ESV.Thirteenth.Int.Conf.Volume.ONE.Section.ONE
ESV.Thirteenth.Int.Conf.Volume.ONE.Section.ONE
ESV.Thirteenth.Int.Conf.Volume.ONE.Section.ONE
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The <strong>Thirteenth</strong><br />
<strong>Int</strong>ernational<br />
Technical<br />
<strong>Conf</strong>erence on<br />
Experimental<br />
Safety Vehicles<br />
$ponsored by:<br />
U.S. Department of<br />
Transportation<br />
National Highway Traffic<br />
Safety Administration<br />
Hosted by:<br />
French Government<br />
Held at:<br />
Paris. France<br />
November 4-7, 1991
fntroduction<br />
The <strong>Int</strong>ernational Experimental Safcty Vehicles (<strong>ESV</strong>)<br />
Program originated under NATO's committee on the Challenges<br />
of Modern Society (CCMS) and was implemcnted<br />
through bilateral agreements between the United States<br />
Govcrnmcnt flnd thc governments of France, the Federafl<br />
Reptrblic of Germany, Italy, thc United Kingdom, Japan,<br />
and Sweden. The participating nations agreed to develop<br />
experimental safety vehicles to advancc thc statc-of-thc-art<br />
in safety engineering and to meet periodically to exchange<br />
technical information on their progress.<br />
To date, twelve international conferences have been held,<br />
each hosted by one of the participating Governments. These<br />
conferences have drawn participants from government, the<br />
worldwide automotive industry, and the motor vehicle safety<br />
rcsearch community. <strong>Int</strong>ernational cooperation in motor<br />
vehicle safety research continues at the highest level. As<br />
work on cxpcrimcntal safcty vehicles was completcd, the<br />
research prograrn cxpandcd to cover the entirc range of<br />
motor vehicle safety. The <strong>ESV</strong> <strong>Conf</strong>erences now serve ils<br />
the international forum through which progress in motor<br />
vehicle safety tcchnology is rcportcd.<br />
The proceedings of each <strong>Conf</strong>erence have been published<br />
by the United States Government and distributed worldwide.<br />
These reports, which detail the safety research efforts<br />
underway worldwide, have been recognized as the definitive<br />
work on motor vchiclc safcty rcscarch. Wc arc sure<br />
that this outstanding example of international cooperation<br />
sccking rcductions in motor vehicle dcaths and injuries will<br />
continue its past succcss.<br />
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Attendees<br />
AUSTRALIA<br />
Brian Fildes<br />
Monash University<br />
Accident l(esearch Centre<br />
Michael Griffiths<br />
Roads & Traffic Authoritv<br />
Peter Makeham<br />
Dept. of Tranriport<br />
fack Mclean<br />
University of Adelaide<br />
BELGIUM<br />
Tadaomi Akiba<br />
Nissan European Tech. Center<br />
Kazuhito Asakawa<br />
J.A.S.r.C.<br />
Kazuhiko Hayashi<br />
Toyota Motor Europe<br />
Yoshihiro Heishi<br />
Nissan European Tech. Center<br />
Herbefi Hennsler<br />
c.E.E.<br />
Susumu Ino<br />
Daihatsu Motor Co., Ltd.<br />
Henk Mannekc'ns<br />
Nissan European Tech. Center<br />
Masami Misaki<br />
Nissan European Tech. Center<br />
Hideo Obara<br />
Nissan European Tech. Center<br />
Keiichi Okabayshi<br />
Toyota Motor Europe<br />
Ushio Ueno<br />
Toyota Motor Europe<br />
Yves Van der Straaten<br />
Ccneral Motors Europe<br />
Hans Van Driessche<br />
Honda Motor Europe<br />
Daniel Verdiani<br />
Commission of European<br />
Communities<br />
Udo Westfal<br />
ACEA<br />
BULGARTA<br />
Krouin Valkov<br />
Ministry of Transport<br />
CANADA<br />
Duncan McPherson<br />
Univcrsity of British Colombia<br />
]ames Newman<br />
Biokenetics Assoc. Ltd.<br />
Stephen Read<br />
University of Waterloo<br />
Christopher Wilson<br />
Road Safety & Motor Vehicle<br />
Rcgulations<br />
CZECHOSLOVAKIA<br />
Vojtech Rieger<br />
U.S.M.D.<br />
DENMARK<br />
Per Frederiksen<br />
|ustice Ministry - Road Safety Div.<br />
Ib Rasmussen<br />
Ministry of Justice/Road Safety<br />
FRANCE<br />
Alain Achard<br />
Renault<br />
Francois Alonzo<br />
I.N.R.E.T.S.<br />
Yves Aubin<br />
Comite des Const. Franc. d'Auto.<br />
Claude Aubry<br />
Autoliv Klippan<br />
Eugene Auffray<br />
F.F.C.<br />
Daniel Augello<br />
Ilenault<br />
Jean-Jacques Azuar<br />
Chausson Engineering<br />
Jean Barge<br />
E.C.I.A.<br />
Marc Behaghel<br />
Comite des Const. Franc. d'Auto.<br />
Agnes Bellini<br />
L.A.B./IJSA - Renault<br />
Farid Bendfallal<br />
L.A.B./IISA - Renault<br />
]. M. Berard<br />
D.S.C.R.<br />
Roger Biard<br />
I.N.R.E.T.S. - L.C.B.<br />
Pierre Bigot<br />
P.S.A. Peugeot Citroen<br />
Georges Blanc<br />
Automobile Normalisation Bureau<br />
Charlcs Blanot<br />
Renault - Direction des Etudes<br />
fean Bloch<br />
I.N.R.E.T.S.<br />
Jean-Claude Bluet<br />
I.N.R.E.T.S.<br />
Felix Bocaly<br />
Pcugcxrt S.A. Research<br />
Marc Bocque<br />
Peugeot S.A.<br />
Serge Bohers<br />
Peugeot S.A.<br />
Jcan Bonnoit<br />
I.N.R.E.T.S. - LBA<br />
Veronique Bordes<br />
I.N.R.E.T.S. - LBA<br />
Antoine Bossard<br />
Automobiles Peugeot<br />
Patrick Botto<br />
Renault - IITACBA<br />
Laurent Bouchard<br />
Renault - IRBA<br />
Robert Bouquet<br />
I.N.R.E.T.S.. L.C.B.<br />
Denis Bourcart<br />
Autoliv Klippan<br />
Jean-Luc Brard<br />
Ireugeot S.A. Research<br />
Pierre Brun<br />
P.S.A.<br />
Francoise Brun-Cassan<br />
L.A.B./PSA - Renault<br />
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13th lnternatlonel Technical <strong>Conf</strong>erence on Experlmental Safety Vehicles<br />
Gilles Brutel<br />
Peugcot S.A. Research<br />
]ean-l,oup Burgaud<br />
Ecolc Centrale de Paris<br />
Marie-Christine Cailleret<br />
Renault - IRACBA<br />
Herve Calmelly<br />
Matra Automobiles<br />
Serge Care-Colin<br />
C.E.T.E. de I'Est<br />
Roland Caroff<br />
Peugeot S.A.<br />
Nelson Casadei<br />
Renault, Research Directorate<br />
Francoise Cassan<br />
Renault<br />
Claude Cavellero<br />
I.N.R.E.T.S. - LBA<br />
Dominique Cesari<br />
I.N.R.E.T.S., L.C.B.<br />
Francois Chamouard<br />
Renault - Biomech./Accident Iab<br />
Paul Charlety<br />
Autoliv Klippan<br />
Remi Chavanne<br />
Automobiles Peugcot - Sochaux<br />
Martine Chereau<br />
Pcugc'ot S,A, Research<br />
Claude Chevalier<br />
Fondation M.I.A.F.<br />
]ean Chewier<br />
R.A.T.P.<br />
Jean-Pierre Cheynef<br />
U.T.A.C.<br />
Alain Clerc<br />
Automobiles Peugeot<br />
Pierre Colinot<br />
P.S.A. Dircction des Etude$<br />
Paul Philippe Cord<br />
LIVBAC<br />
Franck Dauviiliers<br />
Renault - AARMT<br />
Christophe de Baynast<br />
Peugeot S.A. I(esearch<br />
Pascal Deloof<br />
INRETS. CRESTA<br />
Igor Demay<br />
Automobiles Citroen<br />
Andre Deperrois<br />
P.S.A.<br />
|ean Derampe<br />
Peugeot S.A.<br />
Veronique Desgardins<br />
Automobile Citroen<br />
Lambert Detoux<br />
F.F.C.<br />
Louis DeVaulx<br />
P.S.A.<br />
Serge Diet<br />
Renault<br />
Georgcs Dobias<br />
I.N.R.E.T.S.<br />
Claude Dolivet<br />
I.N.R,E,T.S.. L.C.B.<br />
Maric-France Dondel<br />
Rr'nault r Direction dcs Etudes<br />
Regis Dornez<br />
I{enault<br />
Yves Drouadaine<br />
Framasoft CSI<br />
Tour Fiat<br />
Alain Dubos<br />
Renault<br />
Alain Duchesne<br />
Davey Bickford<br />
B. Durand<br />
D.S.C.R.<br />
Marc Ellenberg<br />
C.E.T.E. de I'Est<br />
Philippe Eurin<br />
Ministere, Recherche/Technologie<br />
Denis Even<br />
TELMA<br />
Leonce Evin<br />
Auto Klippan<br />
Jean-Pierre Faidy<br />
P.S.A. DRAS<br />
Gerard Faverjon<br />
L.A.B./Peugeot Renault<br />
Andre Fayon<br />
Renault<br />
Michel Ferlay<br />
I.N.R.E.T.S.<br />
Francis Ferrandez<br />
I.N,R.E.T.S.<br />
Serge Ficheux<br />
U,T.A.C.<br />
Claude Fline<br />
Ministere Recherche/ Technologie<br />
Helene Fontaine<br />
I.N.R.E.T.5.<br />
]ean-Yves Foret-Bruno<br />
Renault<br />
Arnaud Froumajou<br />
Peugeot S.A. Research<br />
]ean Fructus<br />
u.T.A.C.<br />
Philippe Gaches<br />
Peugeot S.A. Research<br />
Gilles Garret<br />
Autoliv Klippan<br />
Bernard Gauvin<br />
D.S.C.R.<br />
Louis Germain<br />
Renault Vehicules Industriels<br />
Olivier Cignoux<br />
I{enault<br />
]ean-Claude Goaer<br />
Renault<br />
Camille Gontier<br />
Ecole Centrale de Paris<br />
Christian Coualou<br />
P.S.A./E.C.P.<br />
Silvie Coujon<br />
Peugeot S.A. Research<br />
Itaymond Guasco<br />
F.I.E.V.<br />
Louis-Robert Guy<br />
PYROSPACE<br />
Mouloud Haddak<br />
I.N.R.E.T.S./L.C.B.<br />
Jean Hamon<br />
P.S.A. DRAS<br />
]ean-Marie Heinrich<br />
L.A.B./PSA - Renault<br />
Claude Henry<br />
L.A.B./PSA - I(enault<br />
Francois Hordonneau<br />
Renault
|ean-Francois Huere<br />
Peugeot S.A. Research<br />
Christophe ]acob<br />
Rcnault - AARMT<br />
]acques Jolivet<br />
Autoliv Klippan<br />
Marco Klingler<br />
INRETS - CRESTA<br />
Serge Koltchakian<br />
Renault - Biomech./Aecidenttab<br />
Michel Kozyreff<br />
Autoliv Klippan<br />
]ean Jacques laine<br />
C.E.T.E., Nord Iricardie<br />
Marc laliere<br />
Rcnault Automobiles Centre<br />
Technique<br />
Patrice [-arguier<br />
P.S.A.. DRAS<br />
Francois l,aurent<br />
Peugeot S.A. Research<br />
Aime LeCalve<br />
Renault<br />
Jean-Yves LeCoz<br />
L.A.B,/PSA-Rcnault<br />
Evelyne l.epoiwe<br />
Renault<br />
Francois Leygue<br />
Ministry of Transport<br />
Richard l"oinand<br />
PYR06PACE<br />
Roland Lucquiad<br />
U.T.A.C.<br />
Philippe Mack<br />
Renault<br />
Jean-Paul Magnier<br />
Davey Bickford<br />
Vincent Maillard<br />
E.C.I.A.<br />
Bruno Margret<br />
GEC ALSTHOM - CIMT<br />
Gerard Martigny<br />
Peugeot S.A. Research<br />
Veronique Martin<br />
Automobiles Citroen<br />
Yves Martin<br />
Automobiles Citroen<br />
Thercse Martinet<br />
Peugeot 5.A.<br />
Gerard Mauron<br />
Peugc'ot S.A. Research<br />
Jean-Pierre Medevielle<br />
I.N.R.E.T.5.<br />
Menard<br />
INNOVATION 128<br />
Serge Morlan<br />
PYROSPACE<br />
Francois Mounier-Poulat<br />
Renault Vehicules Industriels<br />
Richard Najchaus<br />
Renault<br />
Henri Novel<br />
Huliez France<br />
Sean ORiordain<br />
I.N.R.E.T.S. - L.C.B.<br />
laurent Oudenard<br />
Renault - IRBA<br />
fean-Frederic Outters<br />
Automobiles Citrocn<br />
]ean Pages<br />
F.I.E.V.<br />
Christian Perotto<br />
LIVBAG<br />
Claire Petit<br />
Renault - IRBA<br />
John L. Phelps<br />
o.I.c.A.<br />
Yvette Pincemaille<br />
L.A.B./PSA - Renault<br />
Sophie Planque<br />
Renault - AARMT<br />
Yves Portier<br />
A.P.S.A.D., Direction Automobile<br />
Daniel Pouget<br />
Renault<br />
Alain Priez<br />
Renault - IRACBA<br />
Eric Ramaioli<br />
Renault<br />
Michelle Ramet<br />
I.N.R.E.T.S. - L.C.B.<br />
Philippe Ranc<br />
Automobiles Citroen<br />
Attendees<br />
Raymond Ravenel<br />
Comite dcs Const. France D'Auto<br />
fean-Pascal Reille<br />
Renault, Direction des Etudes<br />
Francois Renaudin<br />
SEIiAM, lab. de Biomecanique<br />
|oel ltio<br />
Renault<br />
Nicholas Rogers<br />
IMMA<br />
]ean-Paul Rouet<br />
SAGEM<br />
Patrice Roulois<br />
Heuliez Automobiles<br />
Nakoto Sakai<br />
NIITIDNDENSO<br />
Rene l:rllen<br />
Automobiles Citroen<br />
Patrick Siarry<br />
Ecole Centrale de Paris<br />
Donggang Song<br />
Renault - IRACBA<br />
Olivier Soulie<br />
Automobiles Peugeot-Sochaux<br />
Jean-Pierre Spagnol<br />
Autoliv Klippan<br />
Ceorges Stcherbatcheff<br />
Renault<br />
Christian Steyer<br />
Renault<br />
Xiang-Tong Tao<br />
INRETS LCB<br />
Philippe Tardivon<br />
P.S.A. Direction des Etudes<br />
Claude Tarriere<br />
Renault<br />
Christian Thevenet<br />
C,C.F.A.<br />
Christian Thomas<br />
L.A.B./PSA- Renault<br />
Pierre Toursel<br />
Peugeot S.A. Research<br />
Xavier Trosseille<br />
Renault<br />
Jerome Uriot<br />
Renault - IRBA
13th lnternatlonel Techntcal conference on Experimentat safety vehtctes<br />
Harold Vallee<br />
L.A.B./IrSA - Renault<br />
Gilles Vallet<br />
I.N.R.E.T.S.<br />
facques Van Bunderen<br />
Autoliv Klippan<br />
Kpiakos Vavalidis<br />
Autoliv Klippan<br />
Philippe Ventre<br />
Renault<br />
Michele Vergne<br />
Fondation M.I.A.F.<br />
Roel Verhoog<br />
CESA<br />
Louis-Claude Vrignaud<br />
Sicmcns Automotive S.A.<br />
Gilbert Walfisch<br />
Renault<br />
Remy Willinger<br />
I.N.IT.E.T.S.<br />
GERMANY<br />
Horst Albrecht<br />
Volkswagen AG<br />
Winfried Asmuth<br />
TIJV Rheinland<br />
Toshio Ban<br />
HondaR&DEurope<br />
Hartmut Burger<br />
Volkswagcn AG<br />
Bo Cavell<br />
Autoliv GmbH<br />
Horst Dalibor<br />
Volkswagen AG<br />
Karl Frcderick Ditsch<br />
Ministry of Transport<br />
|ens Eberius<br />
Porsche AG<br />
Harald Eggelmann<br />
Mercedes-Benz AG<br />
Willi Elsenheimer<br />
Adam Opel AG<br />
Eberhard Faerber<br />
Federal Highway Research<br />
Institute<br />
Joerg Fellerer<br />
Bayerische Motoren Werke AG<br />
Detlef Frank<br />
Bayerische Motoren Werke AG<br />
Ioachim Franz<br />
Siemens AC<br />
Bernd Friedel<br />
Federal Highway Research<br />
Institute<br />
Wolf-Richard Frielingsdorf<br />
Mercedes-Benz AG<br />
Klaus-Peter Claeser<br />
Federal Highway Research<br />
Institutc<br />
|wgen Grandel<br />
DEKRA<br />
Iohann Guggenberger<br />
Siemens AG<br />
fosef Haberl<br />
Bayerische Motorcn Werke AG<br />
Hans Hagen<br />
Karl Kassbohrer Fahrzeugwerke<br />
GmbH<br />
l,othar Heider<br />
Mercedes-Benz AG<br />
Wolfram Hetl<br />
University Munich<br />
Thomas Hummel<br />
HUK - Vcrband<br />
Dimitrios Kallieris<br />
University of Heidelberg<br />
Karl-Heinz Kartenberg<br />
Porschc AG<br />
Jorg Kerwath<br />
Hondalt&DEurope<br />
Kikuzo Kitaori<br />
Mitsubishi Motors Europ+ B.V.<br />
]uergen H. Kloeckner<br />
BASt, Federal Highway Research<br />
Institute<br />
Hubert Koch<br />
Industrie Verband Motorrad<br />
Bernhard Koonen<br />
TIJV Rheinland e.V.<br />
Cerald Krabbel<br />
Technische Universitat Bcrlin<br />
Bernd Kraemer<br />
TUV Rheinland e.V.<br />
Hans-Joachim Kraft<br />
Bayerische Motoren Wcrke AG<br />
Heinz Kunert<br />
SEKURIT-GIas Union GmbH<br />
Klaus Langwieder<br />
HUK - Verband<br />
Bog-Soo Lee<br />
Institute of Automobilengineering<br />
Heinz Leffler<br />
Bayerische Motorcn Werke AG<br />
Herbert Loffelholz<br />
Federal Industry of Transport<br />
Horst4eorg Marks<br />
Volkswagcn AG<br />
Gunther Menzel<br />
Volkswagen AG<br />
Yoshimoto Nagamoto<br />
Mazda Motor Corp.<br />
Hiroyaki Nishioka<br />
Toyoda Gosei Co., Ltd,<br />
Michael Popp<br />
Universitat der Bundeswehr<br />
Berud Richter<br />
Volkswagen AG<br />
Ernst-Rudiger Rohr<br />
Mercedcs-Benz AG<br />
Klaus Rompe<br />
TUV Rheinland e.V.<br />
Willibald Roth<br />
Kolbenschmidt AG<br />
Dieter Schaper<br />
Electrolux Autoliv<br />
Thomas Scharnhorst<br />
Volkswagen Ilesearch Forschung<br />
Fahrzeugtechnik<br />
Dieter Scheunert<br />
Mercedcs-Benz AG<br />
Andreas Schindler<br />
TUV Rheinland e.V.<br />
Friedrich-Karl Schlotterbcck<br />
European Components<br />
Deutschland<br />
Achim Schmitz<br />
TIIV Rheinland e.V.<br />
Gerhard Schontag<br />
Mercedes-Bcnz AG<br />
Ruprecht Sinnhuber<br />
Volkswagen AG<br />
Alexandcr Sporner<br />
HUK Verband
Armin Starck<br />
DEKRA<br />
Hans-Eggert Tonnesen<br />
Anton Ellinghaus GmbH & Co. KG<br />
Hidenori LIki<br />
Mitsubishi Motors Europe B.V.<br />
Hans-fosef Vasen<br />
Kolbcnschmidt AG<br />
|esko Veenhuis<br />
Volkswagen AG<br />
Elmar Vollmer<br />
Audi AG<br />
Klaus Von Versen<br />
Engineering Systems <strong>Int</strong>crnational<br />
Lothar Wech<br />
T.U.V. Bayern eV.<br />
Hanns-Pcter Weisbarth<br />
Bayerische Motoren Werke AG<br />
Ulrich Wezel<br />
Porsche AG<br />
Frank Wolf<br />
Mercedes Benz AG<br />
Robert Zobel<br />
Volkswagen AG<br />
HUNGARY<br />
Csaba Siklos<br />
Ministry of Transportation<br />
IRELAND<br />
Denis Wood<br />
Wood and Associates<br />
ISRAEL<br />
Ran Cohen<br />
A.D.A.<br />
ITALY<br />
Elisabetta Amici<br />
Centro Sviluppo Mayterial<br />
Pierluigi Ardoino<br />
Fiat Auto SpA - Centro Sicuarezza<br />
Andrea Benedetto<br />
Fiat Auto SpA - Centro Sicurczza<br />
Dante Bigi<br />
Fiat Auto SpA - Centro Sicurezza<br />
S. Buscaglione<br />
Fiat Auto SpA - Centro Sicurezza<br />
Stefano Buscaglione<br />
Fiat Auto<br />
Fissore<br />
Fiat Auto<br />
F. Fissore<br />
Fiat Auto SpA - Centro Sicurezza<br />
F. Fossati<br />
Fiat Auto SpA - Centro Sicurezza<br />
C. Lomonaco<br />
Ministero dei Trasporti<br />
Fabrizio Luccetti<br />
Fiat Auto SpA - Centro Sicurrezza<br />
lamberto Milani<br />
Italdesign<br />
Silvia Monticelli<br />
Fiat AutoSpA - Centro Sicurezza<br />
A. Pastorino<br />
Fiat Auto SpA - Centro Sicurezza<br />
Claudio Schinaia<br />
Ministero dei Trasporti<br />
F. Zacchilli<br />
Ministero dei Trasporti<br />
JAPAN<br />
Akihiko Akiyama<br />
Honda R & D<br />
Kenji Araki<br />
Sumitomo Metal Industrics, Ltd.<br />
Yoshinori Boda<br />
M.I.T.I.<br />
Mr. Clepkenn<br />
Nissan Motor Cornpany, Ltd.<br />
Hidehiko Enomoto<br />
Hino Motors, Boxy Research<br />
& Development<br />
Naoto Fukushima<br />
Nissan Motor Company. Ltd.<br />
Satoshi Fukushima<br />
Toyota Motor Corporation<br />
Kenichi Goto<br />
]apan Automobile Research<br />
Institute<br />
Attendees<br />
Takeshi Harigae<br />
fapan Automobile Research<br />
Institute<br />
Kazuo Higuchi<br />
Honda R & D, 12th Rescarch<br />
<strong>Section</strong><br />
Kaneo Hiramatsu<br />
fapan Automobile Research<br />
Institute<br />
Masaki Hitotsuya<br />
Fujitsu Ten Ltd.<br />
Kiyoshi Honda<br />
Honda R&D, 1zth Research Scction<br />
Noritoshi Horigome<br />
Ministry of Transport<br />
Masaru Igarashi<br />
Suzuki Motor Corporation<br />
Haruyuki Ikesue<br />
NSK Lrd.<br />
Namio Irie<br />
Nissan Motor Company, Ltd.<br />
Hirotoshi Ishikawa<br />
Japan Automcrbile Research<br />
Institutc<br />
Shin-ichi Ishiyama<br />
Toyota Central R & D Labs, Inc.<br />
Keiji Isoda<br />
Mitsubishi Motors Corporation<br />
Kazuyoshi Katou<br />
Toyota Motor Coryoration<br />
Junichi Kishimoto<br />
Nip1rcn Koki Co., Ltd.<br />
Toru Kiuchi<br />
Toyota Motor Cornoration<br />
Ikuya Kobayashi<br />
Fujitsu Ten Ltd.<br />
Akira Koike<br />
Hino Motors, Vehiele Research<br />
& Exper.<br />
Norio Komoda<br />
Toyota Motor Corp. R&D Planning<br />
Yutaka Kondoh<br />
Toyota Motor Corporation<br />
Ichiro Kurawaki<br />
Yamaha Motor Co., Ltd.<br />
Keiii Kusaka<br />
Kawasaki Heavy Industries, Ltd.<br />
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13th lnternatlonal Technical <strong>Conf</strong>ercnce on Experimental Sefety Vehtctes<br />
Tohru Kuwahara<br />
Isrtzu Motors Limited<br />
Hiroyuki Matsumoto<br />
Mazda Motor Corporation<br />
Inukai Mitsuo<br />
Tokai Rika Co., Ltd.<br />
Toshihito Miyagawa<br />
Toyota Motor Coryoration<br />
Kyoichi Miyazaki<br />
|apan Automobile Rcsearch<br />
Institute<br />
Yoshiyuki Mizuno<br />
Nissan Motor Co., Ltd.<br />
Itsuro Muramoto<br />
Nissan Motor Company, Ltd.<br />
Kosuke Nagao<br />
Ashimori Industry Co., Ltd.<br />
Kenji Nakagawa<br />
Toyobo Co., Ltd.<br />
Akihisa Nakamura<br />
I.A.T.S.S.<br />
Muneo Mshizawa<br />
Takata Corp.<br />
Hideo Obata<br />
CRC Rcscarch Institute Inc.<br />
Akihiro Ohtomo<br />
Nissan Motor Company, Ltd,<br />
Katsumi Oka<br />
Honda R&D, Tochigi Center<br />
Shinichi Sakamoto<br />
Suzuki Motor Corporation<br />
Toshiaki Sakurai<br />
Mitsubishi Motors Corporation<br />
Shouichi Sano<br />
Honda R&D Co., Ltd.<br />
Michihisa Sasonoi<br />
Suzuki Motor Corporation<br />
Kazuhiro Seki<br />
Honda R & D<br />
Katsuhiro Sekine<br />
Pyro Safety Device Co.<br />
Iichi Shingu<br />
Toyota Motor Corporation<br />
Teruhisa Sugita<br />
Takata Corp.<br />
Katsunobu Sumida<br />
Toyota Motor Coryoration<br />
Norio Sumitomo<br />
Toyobo Co., Ltd.<br />
xii<br />
Keizo Suzuki<br />
Tokai Rika Co., Ltd.<br />
Moriyuki Taguchi<br />
Yamaha Motor Co., Ltd.<br />
Nobuhiko Takahashi<br />
Nissan Motor Company, Ltd.<br />
Hideo Takeda<br />
Takata Corporation<br />
Masatoshi Tanaka<br />
Daihatsu Motor Co.<br />
Toshi Tanaka<br />
funsor Technology Co.<br />
Katsunori Taneda<br />
Japan Automobilc Research<br />
Institute<br />
Izumi Tokunaga<br />
Ministry of Transport<br />
funji Tonomura<br />
Suzuki Motor Corporation<br />
Yutaka Tsukiji<br />
Mazda Motor Corporation<br />
Takahiro Tsumga<br />
Toghigi It&D Center<br />
Hiroshi Ueno<br />
Nissan Motor Company, Ltd.<br />
Shuji Yamaguchi<br />
Toyota Motor Corporation<br />
Kuniaki Yamakuse<br />
Honda Motor Co., Ltd.<br />
Takenori Yamamoto<br />
Honda It&D., Ltd.<br />
Yugi Yokoya<br />
Toyota Motor Corporation<br />
Hiroshi Yoshida<br />
Mitsubishi Motors Corporation<br />
Keigo Yoshida<br />
HondaR&DCo.,Ltd.<br />
KOREA<br />
Youngtai Choi<br />
Korea Auto. Test & Res. Instit.<br />
NETHERLANDS<br />
Anna Agter<br />
Ministry of Transport and Public<br />
Works<br />
Hans Ammerlaan<br />
Ministry of Transport<br />
Peter De Coo<br />
TNO l{oad Vehicles Research<br />
Institute<br />
Hans Driever<br />
TNO Road Vchicles Research<br />
Institute<br />
Hans Huiibers<br />
Ministry of Transport<br />
Paul Jacobs<br />
Volvo Car BV<br />
Edgar Janssen<br />
TNO Road Vehicles Research<br />
Institute<br />
Dirk Landheer<br />
Eindhovcn University of<br />
Technology<br />
Henk Lupker<br />
TNO Roacl Vehicles Research<br />
Institute<br />
Jaap Maartense<br />
Volvo Car BV<br />
Cerard Meekel<br />
Ministry of Transportation and<br />
Public Works<br />
Department of Road<br />
Transportation<br />
Yashishi Mizutani<br />
Tokai Rika Co., Ltd.<br />
John Nieboer<br />
TNO I{oad Vehicles Rcscarch<br />
Institute<br />
Joop Pauwelussen<br />
TNO Road Vchicles Research<br />
Institutc<br />
Ian Paul Peters<br />
Yamaha Motor Europe N.V.<br />
Bernard Reys<br />
TNO ltoad Vehicles Rescarch<br />
Institute<br />
Albcrt Roelfsema<br />
Volvo Car BV<br />
L.T.B. Van Kampen<br />
Institute for Road Safety Rcscarch<br />
Carla Van Moorsel<br />
Ministry of Transport<br />
Jan Van Santcn<br />
J.P.M. Van Santen Public Relations<br />
Fred Wegman<br />
Institute for Road Safety Research<br />
|ac Wismans<br />
TNO Itoad Vehicles Research<br />
Institute
Willem Witteman<br />
Eindhoven University of<br />
Technology<br />
RUSSIA<br />
Serguei Efjmenko<br />
State Science and Technology<br />
Committee<br />
Anatolie Eiov<br />
City of Moscow<br />
Vladimir Federov<br />
Ministry of the <strong>Int</strong>erio,r<br />
Vladimir Fedorov<br />
Inspection D'Automobiles de la<br />
Russie<br />
Evgenii Semenov<br />
Foundation for Road Safety<br />
Igor Vengerov<br />
S.T.C.E.C.<br />
Igor Venguerov<br />
Technical Center<br />
SPAIN<br />
Iavier Alvarez-Montalvo<br />
Ministry of Industry and<br />
Commerce<br />
Mercedes Menendez<br />
I.N.T.A.<br />
SWEDEN<br />
Rune Almquist<br />
Volvo Car Corporation<br />
Roger Alven<br />
Alvatrr AB<br />
Sture Andersson<br />
Electrolux Autoliv<br />
Nils Bohlin<br />
Bohlin Consulting/Olstorp<br />
Per Branneby<br />
Saab Automobile AB<br />
Gustaf Celsing<br />
Autoliv Svenge AB<br />
Anders Eugennson<br />
Volvo Car Corporation<br />
Erik Falk<br />
Volvo Car Corporation<br />
knnart Fremling<br />
Swedish Road Safety Office<br />
L. Yngue Haland<br />
Electrolux Autoliv AB<br />
Soren Hedberg<br />
Swedish Road Safety Office<br />
Jan Holmgren<br />
F.T.S.S.<br />
Jan lvarsson<br />
Volvo Car Corporation<br />
Goran Kahler<br />
Saab Automobile AB<br />
]anusz Kajzer<br />
Chalmers University of Technologlr<br />
Birgitta Kamrcn<br />
Folksam Rcsearch<br />
Magnus Koch<br />
Volvo Car Corporation<br />
Maria Koch<br />
Folksam Research<br />
Anders Kull2gen<br />
Folksam Research<br />
Tony Iandh<br />
Saab Automobile AB<br />
Kas Larsson<br />
Saab Automobile<br />
Stefan l-arsson<br />
Volvo Truck Corporation<br />
Thomas lekander<br />
Swcdish Road Safety Office<br />
Anders Lie<br />
Folksam Research<br />
Mats Lindquist<br />
Saab Automobile AB<br />
Per l.ovsund<br />
Chalnrcrs University of Technology<br />
Bjorn Lundell<br />
Volvo Car Corporation<br />
Fritz Hugo Martin Mellander<br />
Volvo Car Corporation<br />
Gert Nilson<br />
Chalmers Univc'rsity of Technology<br />
Curt Nordgren<br />
Assoc. of Swedish Auto. Manuf.<br />
(BIL)<br />
Hans Norin<br />
Volvo Car Corporation<br />
Anders Ohlund<br />
Volvo Car Corporation<br />
fan Olsson<br />
Autoliv Svenge AB<br />
Michael Persson<br />
Volvo Car Colporation<br />
Attendees<br />
Jan Petzall<br />
Chalmers University of Technology<br />
Bengt Iripkorn<br />
Chalnrers University of Technolo6y<br />
Kare I{umar<br />
Swedish Road & Traffic Res.<br />
Institute<br />
V.T.I.<br />
Lennart Strandberg<br />
Swcdish Road & Traffic Res.<br />
Institutc.<br />
V.T.I.<br />
Mats Svensson<br />
Chalmers University of Technology<br />
Sven-Erik Svensson<br />
Volvo Car Corporation<br />
Claes Tingvall<br />
Folksam Research<br />
Thomas Turbell<br />
Swc-dish Road & Traffic Rcsearch<br />
V.T.I.<br />
SWITZERLAND<br />
Itobert Kacser<br />
ETH Zurich<br />
Urs Maag<br />
University of Montreal<br />
Masahiko Naito<br />
Auto. Stand. <strong>Int</strong>emational Ccnter<br />
Gottfried Treviranus<br />
Universtat Zurich<br />
Felix Walz<br />
Institute of Forensic Medicine<br />
UNITED KINGDOM<br />
Gordon Bacon<br />
M.I.R.A.<br />
John F. S. Bidgood<br />
RAC Motoring Scrvices<br />
Philip Bly<br />
Transport & Road Research<br />
laboratory<br />
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1lth lnternatlonal Technlcal <strong>Conf</strong>erence on Experlmentel Satety Vehlcles<br />
Alan Bowker<br />
IJK Transport Dept.-Vehicle<br />
Inspectorate<br />
Jeanne Breen<br />
PACTS<br />
David W. Burleigh<br />
Britax Excelsior Ltd.<br />
Bryan Chinn<br />
Transport & Road Research<br />
Laboratory<br />
Keith Clemo<br />
M.I.R.A.<br />
I-aurence Clift<br />
ICE Ergomanics<br />
Anthony Denniss<br />
T.R.I{.1.<br />
William H. Dixon<br />
Society of Motors Manufacturers<br />
& Traders<br />
Mark Dorn<br />
RSEL, Middlesex Polytcchnic<br />
Eric Dunn<br />
Department of Tmnsport<br />
Alan Dyche<br />
First Technology Systems<br />
Nigel Earle<br />
Ford Motor Company, Ltd.<br />
Malcolm Eden<br />
Ford Motor Company, Ltd.<br />
Paul Fleming<br />
Breed Automotive<br />
Geoffrey Fletcher<br />
Ford Motor Company, Ltd.<br />
Alan Randell Giles<br />
Rovcr Group Ltd.<br />
K. Goense<br />
Airbags <strong>Int</strong>emational<br />
John Harris<br />
Transport & Road Research<br />
Laboratcrry<br />
Julian Hill<br />
University of Birmingham<br />
C. Adrian Hobbs<br />
Transport & Road Rc'scarch<br />
Laboratory<br />
Frcdcrick |ohn Hopc<br />
Hope Technical Developments,<br />
Lrd.<br />
fohn Anthony |eyes<br />
U.K. Department of Transport<br />
xiv<br />
Christopher Kavanagh<br />
Airbags <strong>Int</strong>cnrational<br />
Douglas Kendall<br />
M.I.R.A.<br />
Michael Lewis<br />
Rolls Royce Motors Ltd.<br />
Richard Lewis<br />
Ford Motor Company, Ltd.<br />
Richard Lowne<br />
Transport & Road Research<br />
Laboratory<br />
Murdoch Macaulay<br />
TRRL<br />
Murray Mackay<br />
University of Birmingham<br />
John Miles<br />
Ove Arup and Partners<br />
Andrcw Morris<br />
University of Birmingham<br />
Pat Murphy<br />
U.K. Department of Transportation<br />
Ian Douglas Neilson<br />
P.A.C.T.S.<br />
Robert Newton<br />
ICE Ergonomics<br />
Rock Nigel<br />
ICE Ergonomics<br />
Muir Parker<br />
First Technology Safety Systems<br />
Steve Parkin<br />
University of Birmingham<br />
Ceoffrey Platten<br />
Ogle Design Ltd.<br />
Mostafa Rashidy<br />
Ford Motor Company, Ltd.<br />
Adrian Keith Roberts<br />
Transport & Road Research<br />
Laboratory<br />
Brian Robinson<br />
Transport & Road Research<br />
Iaboratory<br />
Peter I{oy<br />
RSEL, Middle Polytechnic<br />
Majid Sadeghi<br />
Cranfield Impact Center<br />
Geoffrey Savage<br />
RSEL, Middlesex Polytechnic<br />
Pctcr Victor Skuse<br />
Rover Group, Ltd.<br />
Peter Slater<br />
Ford Motor Company, Ltd.<br />
Viv Stephens<br />
M.I.R.A.<br />
Richard Sturt<br />
Ovc Arup and Partners<br />
Peter Thomas<br />
ICE Ergonomics<br />
S. Valkcnburg<br />
Airbags <strong>Int</strong>ernational<br />
Roger Vingoe<br />
HW Structures Ltd.<br />
John Wall<br />
Transport & Road Research<br />
Laboratory<br />
Edmund Ward<br />
ICE Ergonomics<br />
Iraul Wellicome<br />
M.I.R.A.<br />
Nigel Wemyss<br />
Ogle Design Ltd.<br />
Christopher Williams<br />
Ford Motor Company, Ltd.<br />
Christopher Witherington<br />
I{SEL, Middlesex Irolytechnic<br />
UNITED STATES<br />
Stcven Andcrson<br />
ASL<br />
Kenichi Ando<br />
Jetro New York<br />
Robert Arnold<br />
Motor Vehicle Manufacturers'<br />
Assoc.<br />
Robert A. Assunacao<br />
Morgan Melhuish et al.<br />
Thomas Baloga<br />
Mcrccdes-Bcnz NA<br />
Douglas Bc.nnett<br />
U.S. House of Representatives<br />
Barry Berson<br />
Hughcs Aircraft<br />
Donald Bischoff<br />
NHTSA<br />
Russell Brantman<br />
Breed Automotive<br />
American Suzuki Motor Corp.
Terence C'horba<br />
Ccntcrs for Disease Control - F36<br />
Carl Clark<br />
Safcty Systems Company<br />
Robert M. Clarke<br />
NHTSA<br />
Scott Cooper<br />
U.S. House of Representatives<br />
|erry Ralph Curry<br />
NHTSA<br />
Gregory Dana<br />
Association of <strong>Int</strong>ernational Auto.<br />
Manufacturers<br />
Robe* Davenport<br />
University of Zurich<br />
George Davis<br />
NHTSA<br />
Bruca Decker<br />
Toyota Motor Sales, U.S.A.<br />
Robert Denton<br />
Robert A. Denton, Inc.<br />
Kcnncrly H. Digges<br />
University of Virginia<br />
James Donovan<br />
Wilson, Elser, Moskowitz,<br />
Edelman, Dicker<br />
Deborah Ederer<br />
First Technology Safety Systems<br />
William Randall Edwards<br />
Chrysler Corporation<br />
Karl-Heina Faber<br />
Mercedes-Benz of North America<br />
Eugene Farber<br />
Ford Motor Co., Ltd.<br />
Michael Finkelstein<br />
Michael Finkelstein & Associates<br />
David Finncgan<br />
U.S. House of Representatives<br />
|ohn Fleck<br />
I&ITechnologieslnc.<br />
Donald Friedman<br />
Liability Research<br />
Thomas Fugger<br />
Kinematics Research<br />
Junichi Fukuda<br />
Honda R&D North America, Inc.<br />
Peter Fuller<br />
Universitv of l,ouisville<br />
Yoshihiro Goi<br />
Mitsubishi Motors of America<br />
James Hackney<br />
NHTSA<br />
Dictmar Haenchen<br />
Volkswagen of America<br />
Chester L. Hale<br />
American Honda Motor Corp., Inc.<br />
Toni Harrington<br />
Honda North America, Inc.<br />
Philip Hight<br />
Accident Research & Analvsis<br />
Ralph Hitchcock<br />
NHTSA<br />
fan Holgren<br />
First Technology Safety Systems<br />
William Hollowell<br />
NHTSA<br />
Toshio Horiuchi<br />
Nissan Rescarch & Development<br />
Saburo Inui<br />
Toyota Motor Co1p,Services of<br />
N.A.<br />
foseph Kanianthra<br />
NHTSA<br />
Joscph Kennebeck<br />
Volkswagen of America, Inc.<br />
Tawfik Khalil<br />
Motor Vehicle Manufacturers<br />
Association<br />
GM Corporation<br />
Albe* King<br />
Wayne State University<br />
William King<br />
Ford Motor Company, Ltd.<br />
Tadao Kobayashi<br />
American Honda Motor Corp., Inc.<br />
William Leasure<br />
NHTSA<br />
Robert LeFevre<br />
General Motors Corporation<br />
John Lcinotren<br />
Ford Motor Company, Ltd.<br />
David lemmon<br />
University of Cincinnati<br />
Paul Lisovicz<br />
Morgan Melhuish et aL<br />
John Lisowski<br />
Morgan Melhuish et al.<br />
Francois Louis<br />
Rcnault USA<br />
Richard H. Lucki<br />
PSA - USTR<br />
Attendees<br />
James Mahern<br />
Honda R&D North America, Inc.<br />
fuiji Matsumura<br />
Kawasaki Motors Corp., USA<br />
Ed Michcl<br />
Harley Davidson, Inc. :i ,<br />
Manabu Morisaka<br />
Toyota Motor Corp. Serviccs of<br />
Robert Munson<br />
Ford Motor Company, Ltd.<br />
John R. Musgrave<br />
Coburn, Croft & Putzell<br />
Alberto Negro<br />
Fiat Auto USA, Inc.<br />
George Nield<br />
Assoc. of hrtcmational Auto,<br />
Manufarturers<br />
Satoshi Nishibori<br />
Nissan Rcscarch & Development<br />
Linda O'Connor<br />
NHTSA<br />
Brian O'Neill<br />
Insurancc Institute for Highway<br />
Safety<br />
fohn Orlando<br />
U.S. Housc of Representatives<br />
George L. Parker<br />
NHTSA<br />
Helen lretrauskas<br />
Ford Motor Company, Ltd.<br />
Elaine Petrucclli<br />
A.A.A.M.<br />
Geor6;e Irittara, Jr.<br />
First Tcchnology Safety Systems<br />
Wcs Pittman<br />
Vehicle Consultants Inc.<br />
Cortlon Plank<br />
R.S.IJ.A.<br />
Priyaranjan Prasad<br />
Ford Motor Co., Ltd.<br />
Nagarajan Rangarajan<br />
G.E.S.A.C.<br />
Ronald Robbins<br />
Consultrrnt<br />
i1<br />
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13ffi lntefnetbnel Technlcal conterence on Experimentat safety vehtctes<br />
David Romeo<br />
Romeo Engineering<br />
Anthony Sances<br />
Medical College of Wisconsin<br />
Albcrt Schlecter<br />
Chrysler Corporation<br />
Greg Schmeling<br />
Harley Davidson, Inc.<br />
Henry Seiff<br />
M.V.M.A.<br />
Tariq Shams<br />
C.E.S.A.C.<br />
William Shapiro<br />
Volvo Cars of North America<br />
Philip Sheets<br />
Kawasaki Motors Corp., USA<br />
Philip Siracuse<br />
American Suzuki Motor Corp.<br />
Howard M. Smolkin<br />
NHTSA<br />
]ohn Snider<br />
The University of Tennessee<br />
Douglas W. Toms<br />
American Honda Motor Corp., Inc.<br />
Frank Turpin<br />
NHTSA<br />
James Ughetta<br />
Wilson, Elser, Moskowitz,<br />
Edelman, Dicker<br />
Chris Von Will<br />
First Technology Safety Systems<br />
William H. Walsh<br />
NHTSA<br />
Ronald Wasko<br />
Motor Vchicle Manufacturers'<br />
Association<br />
Emroy Watson<br />
Yamaha Motor Corp.<br />
Bill Weber<br />
Hughes<br />
David Weir<br />
Dynamic Research, Inc,<br />
Marc Weiss<br />
Naval Biodynamics Lab<br />
Kenncth Yadvish<br />
Lester, Schwab, Katz & Dwyer<br />
Albert Yamada<br />
Masaoka & Assoc.<br />
Narayan Yoganandan<br />
Medical College of Wisconsin<br />
|ohn Zellner<br />
Dynamic l{esearch, Inc.<br />
Karl-Heinz Ziwica<br />
B.M.W.
<strong>Volume</strong> l. Opening Ceremonies Thru Session 5<br />
Contents<br />
Foreword iii<br />
<strong>Int</strong>roduction ...... v<br />
Attendees ... vii<br />
SECTION 1. OPENING EEREMONIES<br />
Welcomlng Address<br />
Jerry Curry, National Highway Traffic Safety Administration, Department of Transportation<br />
United States<br />
KeynoteAddre$...:.<br />
Jean-Michel Bernard, Minister of Delegation for Road Safety, Arche de la Defense<br />
France<br />
Awards Presentations . . .<br />
Chairman: George L. Parker<br />
Awards for Safety Engineering Excellence . . . 5<br />
Special Awards of Appreciation . I<br />
s E crlo N 2'<br />
o Rr s<br />
f ?Yi-TLf : il,I-lJ$tr-.'nEP<br />
Commissionof theEuropeanCommunities<br />
Daniel Verdiani, Directeur Ceneral, Direction and Cenerale III<br />
...... 9<br />
Germany 10<br />
Karl-Friedrich Ditsch, Ministry of Transport<br />
japan ......15<br />
Noritoshi Horigome, Ministry of Transport<br />
Italy .. 17<br />
Franco Zacchilli, Ministero dei Trasporti<br />
Canada<br />
S. Christopher Wilson, Transport Canada<br />
TheNetherlands ...19<br />
Cerard Meekel, Ministry of Transportation and Prrblic Works<br />
Sweden .....23<br />
Lennart Fremling, Ministry of Transport<br />
xvu
13th <strong>Int</strong>ernatlonal Technlcal <strong>Conf</strong>erence on Expeilmental Safety vehlcles<br />
United States<br />
George L. Parke+ National Highway Traffic Safety Administration<br />
France<br />
George Dobias, Institut National de Recherche sur les Transports et leur Sdcurit6<br />
SECTION 3. TECHNICAL SESSIONS<br />
Technical Session 1r Crash Investigation and Data Analysis<br />
irperson: Fred Wegman, The Netherlands<br />
Cha<br />
sI-o42<br />
; Advanced Accldent Data Collection-Description and Potentials of a<br />
Comprehensive Data Collection System<br />
B. Kamren, M. v Koch, A. Kullgren, A. Lie, A. Nygren, C- Tirrgvall<br />
Folksam Research and Chalmers University of Technology ,,<br />
sl.-o-03<br />
,.... 27<br />
,,,,,.37<br />
Data Linkages in Real Crash Analysis: A Key to Progress in Road Safety 45<br />
Urs Maag, Denise Desjardins, Claire Laberge-Nadeau<br />
Universite de Montreal<br />
sl-o44<br />
ChildCasualtiesinFatalCarCrashes...<br />
, Harold Valee, Marie Christine Caiilieret, Gerard Faverjon, ]ean Yves Le Coz,<br />
jean Marie Heinrich, Christian Thomas<br />
Accident Research and Biomechanics Laboratory Associated with Peugeot<br />
Jean Claude Coltat, Poissy <strong>Int</strong>ercommunal HosPital Centre<br />
ClaudeGot'InstituteofBiomechanicsandAccidentResearch<br />
Alain Patel, Orthopaedic Research lnstitute<br />
...48<br />
I 3t";? Kury*i, of the Speed-Relatecl crash Issue .<br />
Noble Bowie, Marie Walz<br />
National Highway Traffic Safety Administration<br />
sl.-o-05<br />
57<br />
CyclistsandPedestriansinTheNetherlands; DifferentNeeds of InjuryProtection?..........<br />
L.T.B. van Kampen<br />
SWOV Institute for Road Safetv Research<br />
sL-o-08<br />
63<br />
The Cause of Head Iniuries in Real World Crashes<br />
Pete Thomas, Mo Bradforcl, Edmund Ward<br />
Research Institr.rte for Consumer Ergonomics, Lor.rghborough University of Technology<br />
sl-o49<br />
. . . . . 67<br />
Car Model Safety Rating-Further Development Using the Paired Comparison Method . . . . . . 78<br />
M. v Koch, A. Kullgren, A. Lie, C. Tingvall<br />
Folksam Research and Chalmers University of Technology<br />
sl-o-10<br />
Driver Fatality Risk in Two-Car Crashes: Dependence on Masses of Driven and Striking Car . . 83<br />
Leonard Evans, Michael C. Frick<br />
General Motors Research Laboratories<br />
xviii
Contents<br />
s7-o-1.1.<br />
A Collection of Recent Analyses of Vehlcle Weight and Safety 94<br />
Terry M. Klein, Ellen Hertz, Sherry Borener<br />
National Highway Traffic Safety Administration<br />
sl-o-12<br />
CompatibilityProblemsofSmallandLargePassengerCarsinHeadonCollisions<br />
G. Ernst, E. Bnihning, K.P.Glaeser, M. Schmid<br />
Federal Highway Research Instifute, BASt<br />
sl-o-14<br />
Survey of Car-To-Fixed-Obstacle Fatal Crashes 111<br />
Claude Henry, Serge Koltchakian, G6rard Faverjon, Jean Yves Le Coz<br />
Laboratory of Accident Research and Biomechanics Associated with Peugeot SA/Renault SA<br />
Alain Patel, Claude Got<br />
Orthopaedic Research Institute<br />
s1-w-L6<br />
PatternsandcausesofSeriousIn|uryAmongstCaroccupants'<br />
Peter L. Harms<br />
Private Consultant<br />
R.J. Tunbridge<br />
Transport and Road Research Laboratory<br />
sl-w-17<br />
The Use of Crash Injury Research Data by the Vehicle Inspectorate to Identify<br />
Secondary Safety Concerns<br />
Alan Bowker<br />
Department of Transport<br />
135<br />
sl-w-lg ' "<br />
Air Bags in Crashes: Clinical Studies from Field Investigations . .<br />
Donald F. Huelke, Jamie L. Moore<br />
*" " rransp o rta ti o n R es ea rc h I ns t i tu te<br />
ilr';rT:lt-""t#[nl<br />
National Highway Traffic Safety Administration<br />
1rt0<br />
sI-w-21,<br />
The Incidence of Multiple Iniuries in Motor Vehicle Crashes 148<br />
Stephen Luchter, Ruth lsenberg<br />
National Highway Traffic Safety Administration<br />
sL-w-22<br />
Crash Data Plans for the United States 155<br />
William H. Walsh<br />
National Highway Traffic Safety Administration<br />
sl.-w-24<br />
A Proposal for a Simplified Injury Scale "5AIS 9" for Use in Large Scale Accident Studies . . . 1,62<br />
Felix Walz<br />
Institute of Forenslc Medtclne<br />
Klaus langwieder<br />
Office for Motor Vehicle Safety Research, FfUK-Insurers' Association
lSth lnternatlonal Technlcal <strong>Conf</strong>erence on Experlmentel Safaty Vehtctes<br />
sl-w-25<br />
Various Aspects on Crashworthiness Calculations<br />
M. Igarashi, K. Nagai<br />
Suzuki Motor Corporation<br />
sL-w-26<br />
Crash Pulse Recorder (CPR)-Development and Evaluation of a Low Cost Device<br />
for Measuring Crash Pulse and Delta-V in Real Life Accidents .<br />
B. Aldman, A. Kullgren, A. Lie, C. Tingvall<br />
Folksam Research and Chalmers university of Technology<br />
sl-w-27<br />
An Overview of the Vehicle Inspectorate's Database on Bus, Coach and Goods Vehicle<br />
Examinations Following Major Accidents<br />
Donald Macdonald<br />
Department of Transport Vehicle Inspectorate, Accidents, Defect and Recalls Branch<br />
sL,w-28<br />
A General Approach to Estimating Frontal Impact Collision Speeds<br />
Denis P. Wood<br />
Wood & Associates<br />
s1-w-29<br />
Special ProducVPerson CVS-ATB 3-D Simulations . . . .<br />
Donald Friedman<br />
Donald Friedman Liability Research Group<br />
Chairperson: Claudio Schinaia, Italy<br />
s2-o41<br />
<strong>Int</strong>elligent Vehicle Highway Systems-Safety Benefits and Public Policy 205<br />
Eugene I. Farber<br />
Ford Motor Company<br />
sz-o42<br />
Description of Three PROMETHEUS Demonstrators Having Potential Safety Effects . .<br />
Daniel Jean Augello<br />
Renault Research Staff, PROMETHEUS Project Manager<br />
s2-o-03<br />
The First Practical Appllcatlon of a Laser Radar Rear-end Collision Warning System<br />
209<br />
in Production Heavyduty Tnrcks<br />
Itsuro Muramoto, Shigeru Okabayashi, Masao Sakata, Nissan Motor Co., Ltd.<br />
Tohru Yasuma, Kiyoshi Minami, Nissan Diesel Motor Co., Ltd.<br />
Todd Kohzu, Kansei Co., Ltd.<br />
sz-o-04<br />
2'l2<br />
The Anti-Collision Radar in the DRM-SMILER<br />
Pascal Deloof<br />
INRETS-CRESTA<br />
Nathalie Haese, Paul Alain Rolland<br />
CHS-USTLFA<br />
Project . . . 220<br />
i<br />
181<br />
188<br />
792<br />
195<br />
199
Contents<br />
sz-o45<br />
Improved Active and Passive Safety by Using Active Lateral Dynamic Control<br />
and an Unconventional Steering Unit . 224<br />
Per BrHnneby, Bo Palmgren, Saab Automobile AB<br />
Anders Isaksson, Torbjrirn Pettersson, Mecel AB<br />
i<br />
Stig Franz6n, Saab*Scania AB<br />
s2-o45<br />
Proposal for a Guideline for Safety Related Electronics in Road Transport<br />
Systems (Drive Project V1051) 230<br />
Winfried Asnruth, G. Heuser, H. Trier, J. Sonntag<br />
TUV Rheinland<br />
sz-o47<br />
Influence of Electsomagnetic Fields Radiated by Ltghting Discharges<br />
on Automotive Electronic Components<br />
S. Ficheux<br />
UTAC<br />
M. Klingler, M. Heddebaut<br />
INRETS<br />
s2-o-08<br />
235<br />
Improving Vehicle Safety Under Bad Weather . .<br />
]oop P. Pauwelussen<br />
TNO Road-Vehicles Research Institute<br />
sz-o-09<br />
. 239<br />
<strong>Int</strong>eractive Road Signalling-ISls<br />
L" De Vaulx<br />
.<br />
PSA Peugeot - Citroen , ,<br />
s2-Q-10<br />
DetectionandControloftheDegreeofVigilanceofDrivers...<br />
Michel Vallet, Sina Fakhar, Daniel Olivier, Daniel Baez<br />
Institut National de Recherche sur les Transports et leur S6curit6<br />
s2-o-L1<br />
Technical and Medical Aspects Influencing a Motorist's Driving Ability 256<br />
Andrea Costanzo<br />
Rome University "I-a Sapienza"<br />
rechnical<br />
Irsers ':<br />
,i",.r.="Lli.-1,0.::tet"',Ti,$:"0<br />
Co-Chairperson; Kaneo Hiramatsu, Japan<br />
s3-o41.<br />
FactorsthatInfluencetheInvolvementofMotorcycleRidersinTrafficAccidents<br />
Hubert Koch<br />
Industrie-Verband Motorrad Deutschland e. V.<br />
Ulrich Schulz<br />
UniversitAt Bielefeld<br />
s3-o-02<br />
Computer Simulation of Motorcycle Airbag Systems<br />
J.J. Nieboer, A.P. Goudswaard, J. Wismans, E.G. Janssen, A.C.M. Versmissen<br />
TNO Crash-Safety Research Centre<br />
?63<br />
258
lfltl, <strong>Int</strong>ematlonal Technlcal conference on Experlmental satety vehlcles<br />
s3-o43<br />
The Effect of Dummy Leg Design on Motorcycle Crash Test Results . 273<br />
M.A. Macaulay<br />
BruneI University<br />
H. Karimi, B.P. Chinn<br />
Transport and Road Research laboratory, Department of Transport<br />
s3-o-05<br />
Current Situation of Pedestrian Accidents and Research into Pedestrian Frotection in |apan . . 281<br />
Hirotoshi Ishikawa, Kunio Yamazaki, Koshiro Ono<br />
Japan Automobile Research Institute, Inc.<br />
Akira Sasaki<br />
]apan Automobile Manufacturers Association<br />
f,i;3;11'-forTestMethodstoEvaluatePedestrlanProtectionforCars<br />
]. Harris<br />
EEVC Working Croup 10 on Pedestrian Protection<br />
s3-o-07<br />
Development of a Head Impact Test Procedure for Pedestrian Protection 302<br />
K.-P. Glaeser<br />
Federal Highway Research Institute (BASt)<br />
53-O-08<br />
$ubsystem Test for Pedestrian Lower Leg and Knee Protection 310<br />
D. Cesari, F. Alonzo, M. Matyjewski<br />
INRETS<br />
s3-o-09<br />
Finite Element Modelling of Pedestrian Head Impact onto Automobile Hoods . . . . 3'17<br />
David R. Lemmon, Robert S. Ballinger, Ronald L. Httston<br />
Department of Mechanical, Irrdustrlrl and Nuclear Engineering, University of Cincinnati<br />
John Kessler, Jeff Elias, David Zuby<br />
Vehicle Research and Testing Center, Transportation Research Center of Ohio<br />
s3-o-10<br />
The Effect of the Vehicle SEucture's Characteristics on Pedestrian Behavior<br />
Kazuo Higuchi, Akihiko Akiyama<br />
Honda R&D Co., Ltd.<br />
s3-o-12<br />
New Aspects for Optimizing Child Restraint Systems: Experiences from Accidents,<br />
323<br />
Trolley Tests and <strong>Int</strong>erviews .<br />
K. Langwieder, Th. Hummel<br />
HUK-Verband<br />
s3-o-13<br />
Side Protection and Child Restraints-Accident Data and Laboratory Test<br />
330<br />
Including New Test Methods<br />
B. Kamrdn, A. Kullgren, A. Lie, B-4. Skdld, C. Tingvall<br />
Folksam Research and Chalrners University of Technology<br />
s3-o-1.7<br />
. . . .: 341<br />
A Technical Evaluation of Motorcycle Leg Protectors .<br />
Nicholas M. Rogers<br />
<strong>Int</strong>ernational Motorcycle Manufacturers Association<br />
345<br />
XXII
s3-w44<br />
Further Crash Tests of Motorcycle Leg Protectors as ProPosed in the<br />
UK Draft Specification . .<br />
Nicholas M. Rogers<br />
<strong>Int</strong>ernational Motorcvcle Manufacturers Association<br />
Contents<br />
53-W-1,6<br />
APR Proposals for Child Protection in Cars<br />
378<br />
Y. Pincemaille, F. Brun-Cassan, P. Caillibot, J-Y. Le Coz<br />
laboratory of Accidentology and Biomechanics Associated with Peugeot S.A. and Renault (APR)<br />
G. Brutel<br />
P.S.A.-Peugeot{itroen, Laboratory of Automotive Safety<br />
s3-tv-l8<br />
InitialConclusionsofan<strong>Int</strong>enrationalTaskForceonchildReekainingSystems<br />
C. TarriEre, X. Trosseille<br />
Ddpartement des Sciences de l'Environnement, Renault<br />
G. -Carlsson<br />
'l<br />
Volvo Car Corporation<br />
s3-w-20<br />
Wheelchair and Occupant Restraint System For Use In Buses 391<br />
Jan Petziill<br />
Chalmers University of Technology<br />
53-W-22<br />
Bonnet Leading Edge Sub-systems Test for Cars to Assess Protection for Pedestrians . . 402<br />
G.I.L. I-awrence, B.J. Hardy, J. Harris<br />
Transport and Road Research taboratory<br />
s3-w-23<br />
Inadequate Head and Neck Protection of Child Seats<br />
413<br />
Donald Friedman<br />
Liability Research Group<br />
from Advanced Vehicle/flighway Technology<br />
Chairperson: Bernard Durand, France<br />
s4-o41<br />
DriverNeedsandSafetyEffectsofPRoMETHEUSFunctions<br />
H6lEne Fontaine, Cilles Malaterre<br />
Instiht National de Recherche sur les Transports et leur S6curit6<br />
s4-o42<br />
Impact of PROMETHEUS Functions on Traffic Safety<br />
Jtirgen H. Klockner<br />
Federal Highway Research Institute GASI)<br />
424<br />
s4-o-03<br />
The NIITSA MS Program for Enhancing Safety Through Crash Avoidance Improvement 429<br />
William A. Leasure, Jr.<br />
National Highway Traffic Safety Administration<br />
360<br />
x.tilll
Sth <strong>Int</strong>ernatlonel Technlcal <strong>Conf</strong>erence on Experlmentel Selety Vehicles<br />
s4-o44<br />
opportunitiesinAutomotiveSafety:APublicHealthPerspective...<br />
David C. Viano<br />
Ceneral Motors Research Iaboratories<br />
Richard F. Davis, Milford R. Bennett, Robert L. LeFevre, Richard E. Rasmussen, Mitchel C. Scherba<br />
General Motors Corporation<br />
s4-o4s<br />
Safety Aspects of Driving with <strong>Int</strong>elligent Vehicles and <strong>Int</strong>elligent Traffic Systems<br />
Dr.-Ing. Thomas Scharnhorst<br />
Volkswagen AG<br />
449<br />
s4-o-06<br />
PSA Proiect'Tor A Safer Roado<br />
J.P. Faidy, J. Hamon<br />
PSA<br />
454<br />
s4-o47<br />
Automated Vehicle/Highway System<br />
Norio Komoda, Keiji Aoki, Takaharu Saito, Takashi Shigematsu, Hidetoshi Ichikawa<br />
Toyota Motor Corporation<br />
459<br />
s4-o48<br />
'COvER'Safety Synthesis Vehicle 467<br />
Nelson Casadei<br />
Renault<br />
s4-o49<br />
Vehicle Safety ln the 1990's<br />
John M. Leinonen<br />
Ford Motor Company<br />
s4-o-10<br />
Guiding Drivers through a Metropolis: Traffic Safety Aspects of the Guidance and<br />
Information System Berlin (LISB) 479<br />
M.M. Popp, B. Farber, A. Schmitz<br />
University of the Armed Forces<br />
s4-w-L1<br />
Collision Avoldance-Function Allocation to Humans and/or Machines 482<br />
G. Reichart<br />
BMW AG<br />
s4-w-15<br />
FromAccidentologyAnalysistothe<strong>Int</strong>elligentVehicle...<br />
I.P. Colino<br />
ISA Peugeot - Citroen<br />
D. Lechner<br />
INRETS<br />
s4-w-15<br />
Contsol station for Moving Car<br />
A. Clerc<br />
INRETS<br />
s4-w-17<br />
Analysis of EOG and EEG Signals to Detect Lapses of Alertness in Car Driving Simulation . . 499<br />
S. Planque, D. Chaput, C. Petit, C. TarriEre, C. Chabanon<br />
Renault<br />
xxiv<br />
472
Technical Session 5: Side Impact Occupant Protection<br />
' Co-Chairperson: Lan Neilson, United Kingdom<br />
Content$<br />
s5-041<br />
Analysis of Dummy Readings Affected by Secondary Impact Point <strong>Int</strong>ensity<br />
in Side Impact Tests<br />
s05<br />
Tatsumasa Okamoto, Nobuhiko Takahashi<br />
Nissan Motor Co., Ltd.<br />
s5-o43<br />
The Effect of Door Structure on Occupant Iniury in Side Impact<br />
509<br />
Hiroyuki Matsumoto, Hideaki Tanaka<br />
Mazda Motor Corporation<br />
s5-o44<br />
Protection of Occupants Against Side Impact<br />
516<br />
Albert L King, Yue Huang, John M. Cavanaugh<br />
Wayne State University<br />
ss-o45<br />
The Protective Effect of Airbags and Padding in Side Impacts-Evaluation by a New<br />
Subsystem Test Method . . 523<br />
Yngve HAland<br />
Electrolux Autoliv AB<br />
Bengt Pipkorn<br />
Chalmers University of Technology<br />
s5-o-09<br />
Air Bag System for Side Impact Occupant Protection<br />
Toru Kiuchi, Kenji Ogata, Toyota Motor Corporation<br />
Charles Y. Warner, Collision Safety Engineering<br />
John ]ay Gordon, GMH Engineering<br />
s5-o-10<br />
"Renault VSS' Safety Vehicle: Occupant Safety in Side Impacts<br />
J. Rio, D. Pouget, N. Casadei<br />
Renault<br />
s5-o-11.<br />
Parametrlc Study on the Side Impact Simulation of Renault VSS<br />
C. Steyer, R. Najchaus<br />
Renault<br />
s5-o-L3<br />
A Simulation Method of Vehicle Model Coupling with Dummy in Side Impact<br />
Yutaka Tsukiji, Koji Taga<br />
Mazda Motor Corporation<br />
sl-o-1.4<br />
A Resolution of Side Impact Phenomena by Means of Dynamic Nonlinear FEM Simulation<br />
and a Study of Vehicle Body Construction . . 560<br />
Akihiko Inagaki, Nobuhiko Takahashi, Akira Tohyama, Akihiro Ohtomo<br />
Nissan Motor Co., Ltd.<br />
533<br />
542<br />
549<br />
555
13th lnternatlonel Technlcal <strong>Conf</strong>erence on Experlmental Safety vehlcles<br />
ss-o-ls<br />
Results of MVMA Full Vehicle Side Impact Tests on 1990 Model Year Pontiac 6000 Vehicles<br />
Using BioSID and SID 56T<br />
Ronald J. Wasko, Motor Vehicle Manufacturers Association<br />
Kenneth L. Campbell, tlniversity of Michigan Transportation Research Institute<br />
Sherman E. Henson, Ford Motor Company<br />
ss-o-l6<br />
Comparative Perfonnance of SID, BIOSID, and ETJROSID ln Lateral, Pendulum, Sled,<br />
and Car Impacts 573<br />
]oseph N. Kanianthra, Donald T. Willke, Hampton C. Cabler<br />
National Highway Traffic Safety Administration<br />
David S. Zubv<br />
TRC Inc.<br />
s5-o-1,7<br />
Influence of Test Procedure Characteristics on the Severity During Side Impacts . . 588<br />
].A. Bloch, D. Cesari, R. Zac<br />
INRETS<br />
ss-o-L8<br />
A Simple Side Impact Test Method for Evaluating Vehicle Paddings and Side Structures . . . . 592<br />
Mats Lindquist<br />
Saab Automobile AB<br />
si-o-1g<br />
A Dynamic Test Method for a Cay's <strong>Int</strong>erior Side Impact Performance 598<br />
Anders Ohlund, Venti Saslecov<br />
Volvo Car Corporation<br />
sT-o-20<br />
Door Impact Test Procedure and Crush Characteristics for Side Impact Occupant Protection . . 609<br />
Satoshi Fukushima, Shuji Yamaguchi, Tomoyuki Fukatsu, Kenichi Asano<br />
Toyota Motor Corporation<br />
s5-o-21<br />
Crash-Rate and Door-Padding Effects in Side Impact Simulations . . . . 615<br />
Ran Cohen<br />
Armament Development Authority<br />
Edwin M. Sieveka, Wult*r D. Pilkey<br />
University of Virginia<br />
s5-o-22<br />
Evolution and Current State of Development of the Computer-Controlled<br />
Composite Test Procedure . 62l<br />
B. Richter<br />
ACEA/IAMA/h/TVMA<br />
ss-o-23<br />
Current Status of Correlation Between CTP and FST 684<br />
Shuji Yamaguchi<br />
|apan Automobile Manufacturerc Association Inc.<br />
Katsunori Taneda<br />
]apan Automobile Research Institute Inc.<br />
xxvl
Contents<br />
ss-o-24<br />
Future Enhancements of the Computer Controlled Composite Test Procedure (CC-CTP) 646<br />
Ronald J. Wasko<br />
Motor Vehicle Manufacturers Association<br />
s5-o-25<br />
SimulationModelforVehicIePerfornranceImprovementinLateralCollisions<br />
P.I.A.de Coo, E.G. Janssen, A.P. Goudswaard, J. Wismans<br />
TNO Crash-Safetv Research Centre<br />
M. Rashidy<br />
Ford Motor Company<br />
fl*"'jf"solme]ltofaMethodforDynamicSimuIationofSideImpacts<br />
Using a HyGe Accelerator-The S.I.D.E. Procedure<br />
V.M. Stephens, D.G.C. Bacon<br />
Motor Industry Research Association<br />
ss-o-27<br />
tightTruckSideImpactswithSeriousoccupantIniury<br />
Susan C. Partyka<br />
National Highway Traffic Safety Administration<br />
s5-o-28<br />
Development of the MIRA Free-Flight Headform Rig to Simulate Occupant Side-Impact<br />
and Pedestrian Impacts<br />
K.C. Clemo<br />
Motor Industry Research Association<br />
s5-w-29<br />
Experience of Uslng ETJROSID-I ln Car Side Impacts<br />
M.C. Beusenberg, E.G. Janssen, TNO Crash-Safety Research Centre<br />
R. Lowne, A. Roberts, Transport and Road Research Laboratory<br />
K.-P. Glaeser, Bundesarutalt fiir Strassenwesen<br />
D. Cesari,INRETS<br />
ss-w-30<br />
Fatally Iniured Occupants in Side Impact Crashes<br />
Diane C. Lestina<br />
Insurance Institute for Highway Safety<br />
Peter F. Gloyns, Stephen f. Rattenbury<br />
Vehicle Safety Coruultants, Ltd.<br />
ss-w-31<br />
Side Impact <strong>Int</strong>o a Fixed Obiech What is at Stake? . . . .<br />
Mouloud Haddak, Michelle Ramet, Gilles Vallet, Dominique Cesari<br />
INRETS<br />
s5-w-32<br />
Reshained Occupants on the Non-SEuck Side in Lateral Collisions<br />
G.M. Mackay, J. Hill, S. Parkin, J.A.R. Munns<br />
The University of Birmingham<br />
668<br />
673<br />
684<br />
690<br />
707<br />
707<br />
772<br />
xxvll
<strong>Volume</strong> 2. Session 6 Thru Session 10<br />
Contents<br />
SECTION 3. TECHNICAL SESSIONS (CONTINUED)<br />
Technical Session 6: Light Vehicle Rollover<br />
Chairperson: William Leasure, United States<br />
s6-o-01<br />
Pivotal Characterization of Car Rollovers<br />
721<br />
A.C. Malliaris, J. H. DeBlois<br />
DeBlois Associates, Inc.<br />
s6-o4s<br />
Analysis of the Factors Which Influence Rollover Crash Severity TzB<br />
K. Digges, S. Klisch<br />
University of Virginia<br />
s6-o46<br />
Manufacturefs overview of Rollover Resistance Test Technology Tj3<br />
Robert L. LeFewe, Richard E. Rasmussen<br />
General Motors Corporation<br />
s6-o-0s<br />
TheUrbanRollover:Characteristics,Iniuries,Seat-BeltsandEiection<br />
G.M. Mackay, S. Parkin, A.P. Morris, R.N. Brown<br />
Accident Research Unit, University of Birmingham<br />
f,f;?l3" Passenger car Rottover simuration<br />
Toshiaki Sakurai, Yoshiharu Takigawa, Hitoshi Ikeno<br />
Mitsubishi Motors Co., Ltd.<br />
s6-o-71<br />
Roof Collapse and the Risk of Severe Head and Neck Iniury . TSi'<br />
Donald Friedman, Keith D. Friedman<br />
Liability Research Group<br />
s6-w-L2<br />
Effect of Car Size on the Frequency and Severity of Rollover Crashes 765<br />
Charles J. Kahane<br />
National Highway Traffic Safety Administration<br />
xxYul
Technical Session 7: Crash Avoidance Research<br />
ChairPerson; Kare Rumar, Sweden<br />
57-O41<br />
Wheels Anti-Lock Systems for Big Series Passenger Cars .<br />
P. Brun<br />
PSA Peugeot - Citroen<br />
s7-o42<br />
Improvements in Active Safety by Innovation for Automatic Stability Control Systems<br />
Dr.-Ing. Heinz Leffler<br />
BMW AG<br />
s7-o43<br />
Traction ConEol Technology for Improved Driving Safety<br />
Hiroshi Yoshida, Tadao Tanaka, Keiji Isoda, Koichi Kamiya<br />
Mitsubishi Motors Corporation<br />
:<br />
s7-o-04<br />
Controlled Suspension for Bettet Safety<br />
Jmn-Pascal Reille, Charles Blanot<br />
Renault Direction des Etudes<br />
s7-o45<br />
Improvement in High-Speed Safety Through Active Suspension Control<br />
Naoto Fukushima, Namio Irie<br />
Nissan Motor Co., Ltd.<br />
Contents<br />
s7-0-06<br />
Development of Tyre Checking Equipment<br />
802<br />
Roland Lucquiaud<br />
U.T.A.C.<br />
s7-o-07<br />
How About the Average Drlver ln a Crltlcal Situation? Can He ReaIIy Be Helped<br />
by Primary Safety Improvements? .<br />
805<br />
Alain Priez, Institut de Recherche Anatamo-Chirurgical et de Biomecanique Appliqu6e<br />
Claire Petit, Instihrt de Recherche Biom6canique et Accidentologique<br />
Bruno Gu6zard, Lionel Boulommier, Association d'Aide i la Recherche int6ressant<br />
la M6decine du Travail<br />
Andr6 Dittmar, Alain Delhomme, Laoratoire de Thermor6gulation CNRS LJRA<br />
Evelyne Vernet-Maury, Universitd C. Bernard<br />
Edwidge Pailhous, Psychologist, 82 bd. Buzenval, Paris<br />
Jean-Yves Foret-Bruno, Claude Tarriere, Renault France<br />
s7-o48<br />
CrashAvoidanceCapabilityof50DriveIsinDifferentCarsonIce..<br />
Lennart Strandberg<br />
Swedish Road and Traffic Research Institute, VTI<br />
s7-o-10<br />
Simulation as a Design Aid 826<br />
E. Cirardot, P. Tardivon<br />
PSA Peugeot-Citroen<br />
77"1<br />
m<br />
784<br />
790<br />
,T<br />
H :lt<br />
r,i<br />
' : i<br />
794 iI<br />
I;<br />
'+<br />
il<br />
,d<br />
I'r:<br />
ifi
13th lnternatlonal Technlcal Conterence on Expefimentel Safety Vehlcles<br />
s7-o-LL<br />
Analysis of Accidents in Right Turns Using aEvzzy Logic Simulation Model 830<br />
Hiroshi LIeno, Kiyoshi Ochiai<br />
Nissan Motor Co., Ltd.<br />
XXX<br />
Technical Session 8r Biomechanics and Dummy Development<br />
Chairperson: Dominique Cesari, France<br />
si-o{/1<br />
Evaluation of Impact Responses of the EUROSID-I and BIOSID<br />
Takeshi Harigae, Koji Ohsaki, Haruo Ohmae<br />
Japan Automobile Research Institute, Inc.<br />
Tatsumasa Okamoto, Masayoshi Hayashida<br />
]apan Automobile Manufaiturers Aisociation, Inc.<br />
s8-o42<br />
The Biofidelity of the Production Version of the European Slde Impact Dummy<br />
"EUROSID-IU<br />
. ,<br />
8s0<br />
A.K. Roberts, M. Beusenberg, D. Cesari, K-P. Glaeser<br />
European Experimental Vehicles CommittepWorking Group 9<br />
s8-o43<br />
A Comparison of Hybrid III and Cadaver Thorax Response Under Diagonal Belt Loading<br />
Serin 6 Riorddin, Michelle Ramet, Dominique Cesari, Robert Bouquet<br />
INRETS<br />
s8-o-04<br />
The Use of a Multi-Accelerometric Method ln Automotive Safety Tests<br />
862<br />
L. Oudenard, F. Bendjellal, A. Bellini, ]. Uriot<br />
Peugeot S.A./Renault<br />
sl-o-0s<br />
EUROSID I and BIOSID Impact Response Characteristics vg. ISO Biofidelity Requirements . . 877<br />
F. Bendjellal, G. Fuld, E. Hautmann, M. Koch, H. Marks, A. Pastorino<br />
ACEA Working Croup on Dummies<br />
s8,o-05<br />
Scaling HYBRID III and Human Head Kinematic Responses to Frontal Impact<br />
887<br />
Marc S. Weiss, Sal Cuccione<br />
Naval Biodynamics Laboratory<br />
Terry A. Watkins<br />
Universify of New Orleans<br />
s8-o47<br />
Facial Fracture Probability $econdary to Steerlng Wheel Impact<br />
891<br />
Narayan Yoganandan, Anthony Sances, Jr., Frank Pintar, John Reinartz<br />
Medical College of Wisconsin<br />
Mark Haffner<br />
National Highway Traffic Safety Administration<br />
s8-o-09<br />
An Improved Finite Element Model of the Human Thorax<br />
902<br />
Cordon R. Plank<br />
Volpe National Transportation Systems Center<br />
Rolf H. Eppinger<br />
National Highway Traffic Safety Administration
s8-o-1.0<br />
Analytical Trauma Reserrch Using the Chest Band<br />
Nopporn Khaewpong<br />
Chi Associates, Inc.<br />
Rolf H. Eppinger, Richard M. Morgan<br />
National Highway Traffic Safety Administration<br />
s8-o-1,1.<br />
3-D Anatomic Brain Model for Relating Cortical Strains to Automobile Crash Loading<br />
F. Dimasi ,,<br />
Volpe National Transportation Systems Center<br />
J. Marcus, R. Eppinger<br />
National Highway Traffic Safety Administration<br />
s8-o-12<br />
Dynamic Studies with Chest Contours<br />
David Skrade, Narayan Yoganandan, Anthony Sances, Jr., John Reinartz, Frank Pintar<br />
Medical College of Wisconsin<br />
ff"o*,'1-,*,-oneElementtoAssessPassiveSafetyofPassengerCars<br />
A. Schmitz, B. Kraemer<br />
fUV Rtreinland e.V., Institute of Traffic Safetv<br />
s8-w-15<br />
Analysis Method for External Forces Acting on the Dummy<br />
Koushi Kumagai, Fumio Matsuoka, Hiroyuki Takahashi<br />
Toyota Motor Corporation<br />
s8-w-1,6<br />
Brain Tolerance in the Frequency Field .<br />
R. Willinger, D. Cesari<br />
INRETS-LCB<br />
C.M. Kopp<br />
IMFS<br />
s8-w-17<br />
Development of a Sternum Displacement Sensing System for Hybrid III Dummy . . .<br />
Kenji Ogata, Masakazu Chiba<br />
Toyota Motor Corporation<br />
Hisashi Kawai, Fumio Asakura<br />
Nippon Soken, Inc.<br />
s8-w-18<br />
Test Procedures for Defining Biofidelity Targets for Lateral Impact Test Dummies<br />
A.K. Roberts, R.W. Lowne, M. Beusenberg, D. Cesari<br />
European Experimental Vehicles CommittetsWorking Group I<br />
s8-w-19<br />
Influence of the Seat and Head Rest Stiffness on the Risk of Cervical Iniuries<br />
in Rear Impact<br />
|.Y. ForeFBruno, F. Dauvilliers, C. Tarriere, P. Mack<br />
Renault<br />
s8-w-20<br />
Improvements in the ATB/CVS Body Dynamics Model<br />
John T. Fleck<br />
I&JTechnologieslnc.<br />
Contents<br />
907<br />
916<br />
9?4<br />
930<br />
936<br />
940<br />
947<br />
974<br />
xxxl
13th lnternetlonal Technlcal <strong>Conf</strong>erence on Experlmental Safety Vehlcles<br />
Technical Session 9: Frontal Crash Protection<br />
Chairperson: S. Christopher Wilson, Canada<br />
s9-o41<br />
Influence of Rigid Wall Impact Speed on Dummy and Vehicle Loadings 977<br />
Eberhard Faerber<br />
Federal Highway Research Institute (BAS0<br />
sg,o42<br />
Full Size Semi-Frontal Crash Simulations with Passenger Cars at 55 km/h<br />
Against Rigid Barrier 986<br />
Florian Schueler<br />
Insitute for Forensic Medicine, University of Heidelberg<br />
Peter Hupfer, Lothar Wech<br />
TW BAYERN<br />
s9-o-03<br />
Test Procedure Comparison in Frontal Impact 988<br />
Gilles Vallet, Dominique Cesari, Yves Derrien, SeAn 6 Riorddin<br />
INRETS<br />
s9-o-04<br />
The Effects of FMVSS No. 208 and NCAP on Safety as Determined<br />
ftom Crash Test Results . . .<br />
993<br />
James R. Hackney<br />
National Highway Traffic Safety Administration<br />
59-O-05<br />
AvoidingSub.opHmizedoccupantSafetybyMultipleSpeedImpactTesting<br />
Hans Norin, Clas jernstrcim, Magnus Koch, Stephan Ryrberg, Sven-Erik Svelrsson<br />
Volvo Car Corporation<br />
s9-046<br />
Improving the Protection of Restrained Front Seat Occupants in Frontal Crashes<br />
D.f. Dalmotas, E.R. Welbourne<br />
Transport Canada<br />
1'027<br />
sg-o47<br />
Upper <strong>Int</strong>erior Head Impacts: The Safety Performance of Passenget Vehicles . . 1037<br />
Hampton C. Gabler, Donald T. Willke<br />
National Highway Traffic Safety Administration<br />
J. Joseph Wagner<br />
Automated Sciences Group, Inc.<br />
s9-o48<br />
A Study of the Safety Performance of Production Vehicles Equipped with Driver Air Bags<br />
in the NHTSA Test Programs<br />
1047<br />
William T. Hollowell, Fabienne ]. Frey<br />
National Highway Traffic Safety Administration<br />
s9-o-09<br />
Supplemental Air Bag Restraint Systems: Successes and Challenges 1054<br />
Robert H. Munson, ]oseph C. Marsh<br />
Ford Motor Company
s9-o-10<br />
Seat Belt Ptetensioners to Avold the Risk of Submarining-A Study of Lap-Belt<br />
Slippage Factors<br />
Yngve HAland<br />
Electrolux Autoliv AB<br />
Gert Nilson<br />
Chalmers University of Technology<br />
s9-o-11<br />
A Preliminary Field Analysis of Chrysler Driver Airbag Effectiveness<br />
W. Randall Edwards<br />
Chrysler Corporation<br />
sg-o-12<br />
The Need for Improved Shuctural <strong>Int</strong>egrity in Frontal Car Impacts . . .<br />
C. Adrian Hobbs<br />
Transport and Road Research l.aboratory<br />
s9-o-1.3<br />
Frontal Impact Protection Requires a Whole Safety System <strong>Int</strong>egration ' . . . ;<br />
C. Tarriere, C. Thomas, X. Trosseille<br />
Renault<br />
s9-o-L4<br />
Occupant Protection in Coaches<br />
Ross Dal Nevo, Paul Duignan, Michael Criffiths<br />
Roads and Traffic Author*ity of NSW<br />
fl""^T g"g* Co*patible with Child Reshaint Systems and Roadside Safety Featwes?<br />
Thomas Turbell<br />
Swedish Road and Traffic Research Institute, VTI<br />
ihl'lf-t Airbas Model for the ArB Prosram<br />
Tariq Shams, Nagaraian Rangarajan<br />
GESAC, Inc.<br />
s9-o-18<br />
Finite Element Simulation of Airbag Deployment and <strong>Int</strong>eractions With an OccuPant Model<br />
Using DYNASD<br />
T.B. Khalil, General Motors Corporation<br />
R.J. Wasko, Motor Vehicle Manufacturers Association of the U.S'A.<br />
J.O. Hallquist, D.J. Stillman, Livermore Software Technology Corporation<br />
s9-o-19<br />
Modelling the Occupant in a Vehicle Context-An <strong>Int</strong>egrated Approach . . .<br />
R.M.V. Sturt, B.D. Walker, J.C. Miles<br />
Ove Arup & Partners<br />
A. Giles, N. Grew<br />
Rover Group Limited<br />
s9-o-20<br />
Advances in Problem-Adaptive Occupant Modelling with PAM-SAFE<br />
X. Ni, D. Iasry, E. Haug<br />
Engineering Systems <strong>Int</strong>ernational S.A<br />
R. Hoffmann<br />
Engineering System <strong>Int</strong>ernational GmbH<br />
Contents<br />
1060<br />
1058<br />
r07g<br />
tj<br />
H<br />
I<br />
_i<br />
l<br />
'.<br />
7079 '# j::<br />
1088<br />
1 103<br />
,<br />
:<br />
d<br />
ix<br />
..-<br />
1095 =<br />
1 1.tl<br />
L ILI<br />
..<br />
..i-?<br />
:]<br />
i; -1<br />
1098 , -l<br />
;<br />
;<br />
;l<br />
'<br />
.4<br />
:t<br />
.'i<br />
r,<br />
:i.<br />
1114 ,,<br />
i;l<br />
xxxlll<br />
i-t<br />
ai<br />
t-<br />
j<br />
it<br />
1t
13th lnternetlonel Technlcal <strong>Conf</strong>erence on Experlmentel Sefety Vehlcles<br />
s9-o-21<br />
Design Considerations of the Passenger Airbag System . . . . ; 7727<br />
Kazuhiro Seki, Kanichi Fukuda, Kiyoshi Honda<br />
Honda R&D Co., Ltd.<br />
sg-o-22<br />
Achievable Optimum Crash Pulses for Comparhnent Sensing and Airbag Performance . . . . . 1134<br />
Russel Brantman<br />
Breed Automotive<br />
s9-o-23<br />
The MADYI\{O Finite Element Airbag Model 1139<br />
H.A. Lupker, H.B. Helleman, E. Fraterman, J. Wismans<br />
TNO Road-Vehicles Research Institute<br />
s9-o-25<br />
TheDeveloPmentofaComputerProgramtoEnhancetheFitofSeatBelts<br />
Doug Kendall<br />
Crash Protection Centre, Motor Industry Research Association<br />
sg-w-17<br />
ValidationandDescriptionof"PASSIM-PLUs"PassengerAirbagModel<br />
Michael U. Fitzpatrick, Kelly E. Thompson<br />
Fitzpatrick Engineering<br />
s9-w-26<br />
Performance Evaluation of Crash Test Data Acquisition Systems 1"157<br />
Randa Radwan<br />
National Highway Traffic Safety Administration<br />
]ohn Nickles<br />
Research and Special Programs Administration, U.S. Department of Transportation :'<br />
s9-w-27<br />
New Technique Used by P.S.A. for Creating Dynamic Test Apparatus<br />
Enabling Crash Simulation in Accordance with Programmed Laws 7171.<br />
C. Mauron, F. Bocaly, F. Laurent<br />
PSA Peugeot - Citroen<br />
A. DepreFBixio, A. Grenier<br />
Domange-]arret<br />
s9-w-29<br />
A New Compact European Driver Airbag Svstem 1176<br />
Michel Kozyreff<br />
Autoliv Klippan<br />
?f,:T"*Hr:,l<br />
s9-w-31<br />
Overlap Car-to-Car Tests Compared to Car-to-Half Barrier and Car-to-Full Barrier Tests 1180<br />
Carl Ragland, Gayle Dalrymple<br />
National Highway Traffic Safety Administration<br />
s9-w-32<br />
COVER: "Renault \/SS" Safety Vehicle Frontal and Rear Impact Occupant Protection 1186<br />
G. Walfisch, D. Pouget, N. Casadei<br />
Renault<br />
xxxlY
Contents<br />
s9-w-34<br />
Engine Bay Packaging for Crashworthiness Perfomence .<br />
P.V. Skuse, N.D. Grew<br />
Rover Grotrp Limited :,* :<br />
s9-w-35<br />
Improving Rear Seat Safety-A Continuing Proces$ 1194<br />
Bjtirn Lundell, Gerd Carlsson, Petter Nilsson, Michael Persson, Camilla Rygaard<br />
Volvo Car Corporation<br />
s9-w-36<br />
Could a Lap Belt in the Rear Centre Position Save Hunran Lives? 1201<br />
j.Y. Foret-Bruno, C. Tarriere, Renault<br />
L.oudenard,C.Got,InstitutdeRecherchesBiom6caniquesetAccidentologiques<br />
D. Song, Societd d'Etudes et Recherches des Arts et Mdtiers<br />
A . P a t e l , I r r s t i t u t d e R e c h e r c h e s o r t h o p 6 d i q u e s . - .<br />
59-l,V-38<br />
Parameterg Affecting the Perfortrance of Framed Child Seats Anchored by Adult Belts . . . . . 1205<br />
M.R. Dorn, A.P. Roy<br />
Middlesex Polytechnic<br />
R.W. Lowne<br />
Transport and Road Research I*aboratory<br />
s9-w-39<br />
Aged, Used, Crashed Seat Belts 1213<br />
Paul Duignan, Michael Griffiths<br />
Roads and Traffic Authoritv of NSW<br />
s9-w40<br />
Strucfural ConsideraHons in Air Bag Sensor Activation at Low Threshold Test Speed 7220<br />
Matthew Huang, Cassandra Green, Frederick Samson<br />
Ford Motor Company<br />
s9-w42<br />
Application of New Elastic-Plastic-Brittle Material Models to Composite Crash Simulation . . 1227<br />
E. Haug, O. Fort, G. Milcent, A. Trameqon, Enfiineering Systems <strong>Int</strong>ernational S.A.<br />
M. Watanabe, L Nakada, T<strong>ONE</strong>N Corporation<br />
T. Kisielewicz, ESI-APG<br />
59-W43<br />
Identification of Automobile Structural Characteristics from Barrier Crash Tests 7234<br />
Clifford C. Chou, Yun S. Lin<br />
Ford Motor Company<br />
ss-w46<br />
An <strong>Int</strong>elligent Solution to frontal and Side Impact Protection . . . 7245<br />
S. Murtuza<br />
University of Michigan-Dearborn<br />
sg-o47<br />
Optimized Passenger Safety ln the Compact Class<br />
Prof. Dr.-Ing. U. Seiffert<br />
Volkswagen AG<br />
:.!<br />
ff<br />
:r1<br />
ri<br />
:ll<br />
ai<br />
i:
13th <strong>Int</strong>ernatlonal Technlcal <strong>Conf</strong>erence on Experlmental Safety Vehicles<br />
Technical Session 101 Heavy Truck Safety<br />
Chairperson: Bernd Friedel, Federal Republic of Germany<br />
sl0-o-07<br />
Large Truck Safety in the U.S. . 1257<br />
Henry E. Seiff<br />
Motor Vehicle Manufacfurers Association of the U.S., Inc.<br />
sl0-o-02<br />
Typical Risk Situations in Car to Truck Accidents-The Necessity of Improving<br />
the Conspicuity of Trucks<br />
M. Danner, K. Langwieder, H. Biiumler<br />
HUK-Verband<br />
'1266<br />
s10-o-03<br />
Improving HGV Safety-Front Undernrn Guards and Anti-Lock Braking Systems 1275<br />
B.J. Robinson, B.S. Riley<br />
Transport and Road Research Laboratory<br />
s10-o-04<br />
Passenger Protection in Single and Double-Decker Coaches in Tipping Over . 1284<br />
P. Botto, M.C. Caillieret/ A. Patel, Institut de Recherches Orthopddiques<br />
C, Got, Institut de Recherches Biom6canique et Accidentologique<br />
C. TarriEre, Renault<br />
'<br />
s1.0-o-05<br />
Influence of Different Loading <strong>Conf</strong>igurations on the Driving Behaviour<br />
of Heavy Commercial Vehicles . . .<br />
729?<br />
Andreas Schindler<br />
TW Rheinland e.V., Institute of Traffic Safety<br />
51.0-0-05<br />
Reliability, Maintainability, and Durability of Heavy Truck ABS Systems . , 1298<br />
Robert M. Clarke<br />
National Highway Traffic Safety Administration<br />
sl0-o-07<br />
New Concept of Brake for Heavy Duty Vehicle 1313<br />
Tohru Kuwahara<br />
Isuzu Motors Ltd.<br />
Kenji Araki<br />
Sumitomo Metal Industries Ltd.<br />
s10-0-08<br />
Experimental Accident Simulation for Improved Safety of Tank Vehicles<br />
foi Dangerous Goods . . . .<br />
K..Rompe<br />
TLIV Rheinland e.V., Institute of Traffic Safety<br />
s1,0-o-09<br />
UNITAS ZilXFEnvironment and Nature Protection Related <strong>Int</strong>egrated Tanker Safety<br />
Hans-Eggert Tonnesen<br />
Anton Ellinghaus GmbH & Co. KG<br />
xxxvl<br />
'13?4
Welcoming Address<br />
Jerry Curry, Administrator<br />
National Highway Traffic S afety Adminisnation<br />
Depa-rtment of Transportation<br />
United States<br />
The date is January 25, 1971, the place is Paris, the<br />
event is the First <strong>Int</strong>crnational Technical <strong>Conf</strong>erence on<br />
Experimental Safety Vehicles. It is appropriate to return<br />
to this beautiful and famous city for the 20th anniversary<br />
year conference.<br />
Many of us, perhaps most, were not here in January<br />
1971. Yet we are pioneers no less, because we pick up<br />
the challenge and movc ahead, just as the far'sighted<br />
re$earchers, und engineers, and government managers of<br />
that day did.<br />
We have one advantage: Hindsight. We can see and<br />
measure progress of the past two decades. We can be<br />
comfortable in the knowledge that what we are doing is<br />
right.<br />
One of those 1971 pioneers was Robert Brenner, the<br />
Chief Scientist for my agency, the sponsoring National<br />
Highway Traftic Safety Administration. Dr. Brenner's<br />
closing reflections at that l'irst conference included this<br />
borrowed quote (and I am paraphrasing).<br />
".<br />
. . We should never expect to employ in practice all<br />
the motive power of the combustibles used . . . this<br />
effort could be more harmful than useful the<br />
cconomy of fuel is only onc conditictn which should be<br />
fulfilled. . . . In many coses it is secondary . . . it must<br />
often yield precedencc to safety ." Many pcople<br />
committed to auto silfety mi8ht have said that, cven<br />
today.<br />
But'thesc wcre not the words of a govcrnment leader,<br />
or itn automotive industry official, or even of an<br />
advocacy group. No, this wa$ the observation of Jacques<br />
Camot, a Frenchman and a legend in scicntil'ic and<br />
engineering circlcs. Today we can still apprcciate his<br />
insight.<br />
Dr. Brenner of NI{TSA also made another statement,<br />
a simple declaration of fact pertinent to the times . . . he<br />
said: "and then there are 55,000 or more who die every<br />
year in the United Statcs in traffic crashes."<br />
Today I can recast that line its follows: And then there<br />
are the 45,529 who dicd last year in the United Statss in<br />
traffic crashes.<br />
<strong>Section</strong> I<br />
Opening Ceremonies<br />
Another statement of fact, but a rcmarkable difference<br />
in numbers; the morc so when the astounding growth in<br />
the totals of drivcrs, cilrs and milcs traveled is<br />
considered.<br />
Winston Churchill said "History will be kind to me,<br />
because I intend to write it." We don't need to write<br />
anything about the fruits of confcrences like this one.<br />
Wc can look at the record and see pure accomplishment<br />
in thc statistics.<br />
Doug Toms, who held my job in 1971, attended the<br />
"Now<br />
second <strong>ESV</strong> <strong>Conf</strong>erence and commcnted: we have<br />
a worldwide effort on expcrimcntal safety vehicles."<br />
That wasn't quite true. Wc took steps to correct that<br />
this year. We invited the nations of Eastern Europc to<br />
USSR participate, and I am grafified that a numbcr of<br />
thcm have accepted Bulgaria, Czechoslovakia,<br />
Hungary, and the Union of Soviet Socinlist Rcpublics.<br />
So for the first time these nations will bc ablc to share<br />
in the tcchnical wisdotn that flows in such abundatrce at<br />
<strong>ESV</strong> <strong>Conf</strong>erences. And I am plcased too that Korea also<br />
takes part for thc first time.<br />
Tho record of the 1970's and 1980's says clearly that<br />
the junction of nations which we have achicvcd through<br />
<strong>ESV</strong> confercnces resulted in a crash-worthy pilssengcr<br />
car,<br />
Not a perfect cafi we are still experimenting, after all.<br />
But a very fine car-a vehicle with improved frontal<br />
crash protection, with stronger sides, a fricndlier interitlr<br />
and better occupant restraints.<br />
And most of all, restraining systcms that rob the crash<br />
forces of much o[ thcir capacity to kill and cripple.<br />
In thc United States only last year we stepped forward<br />
again, introducing an improved side impact protcction<br />
standard that will be tested dynamically; this standard<br />
alonc will save another 500 livcs in the United States<br />
every yeflr.<br />
You will talk at this confercnce about what rcmains to<br />
be done with the car. Rollovcr propensity for cxample'<br />
And anti-lock brakes, which happily, in America, are<br />
beconring a standiud itcm without the necessity of a<br />
govcrnrlrent requirement.<br />
But anothcr challenge remains on the horizon, waiting<br />
to bc addressed in depth. Not a new subjecl, bccausc the<br />
failures of the driver have always bccn rccognized as a<br />
root problcm of vehicle crashes.
1ilth <strong>Int</strong>ernatlonal Technlcal <strong>Conf</strong>erence on Experlmentel Sefety Vehlcles<br />
When then-U.S. Secretary of Transportation John<br />
Volpc asked an early <strong>ESV</strong> <strong>Conf</strong>erence whether industry<br />
could design a really safc car that also offered good<br />
engine performance, reduced emissions, attractive<br />
styling, and susceptibility to mass production at a<br />
reasonable price, it was an arrow to the bullseye.<br />
Now we have a new target. I pose the query this way:<br />
Can we design a really safe driver, one capable of<br />
dealing with any traffic emergency, and uncxpccted<br />
situation? Can we $natch a crash-bound driver from the<br />
jaws of tragedy?<br />
Might we call this driver an ESD-an experimental<br />
$afety driver, symbolic of the search for crash-free<br />
operation? Of course we can't achieve perfection, but we<br />
can reach for it-<br />
The course of major research in the 1990's should, in<br />
our view, be dirccted to making drivers hetter. Be<br />
cautious with my phrase. I didn't say making Detter<br />
drivers. Although the attempt to raise driving skills<br />
through training and education remains a desirable<br />
objective.<br />
The massive effort mounted to rcduce impaired<br />
driving has been demonstrably effective, for example.<br />
But making drivcrs bctter is an entirely different art<br />
form, almosl a new frontier, accommodating the machine<br />
to the human, rather than vice versa.<br />
The time is here to acknowledge that drivers<br />
inevitably make mistakes. The error-free driver is<br />
beyond our scopc. But the virtually crash-frce drivcr may<br />
be within the probable realm if we can extend the right<br />
kind of helping hand.<br />
The 1990's and beyond will be the era of elcclronic<br />
intervcntion, the inscrtion of an automatic warning or<br />
rcsponse to avert a crash situation before thc driver finds<br />
himself in thc web of disaster. This sounds like<br />
electronic legerdemain, but there will be no magic short<br />
of long and painstaking research in what we now call<br />
"<strong>Int</strong>elligent<br />
Vehicle Highway Systems."<br />
Measuring the human capacity to absorb the wizardry<br />
of thc special sensors, and monitors, and braking and<br />
steering overrides, and a potential multiplicity of dials<br />
and gadgets presupposes the human factors research that<br />
dctermines whether humans will be helped or hurt by a<br />
spccific device.<br />
Another facet, then, is crcating a rcalistic experimcntal<br />
environment where real people are cast into real highway<br />
Keynote Address<br />
Jean-Michel Berard<br />
Minister of Delegation for Road Safety<br />
Arche de la Defense<br />
France<br />
I am pleased to open this <strong>Thirteenth</strong> <strong>Int</strong>ernational<br />
<strong>Conf</strong>erence on Experimental Safety Vehicles, which is<br />
being held in Paris for the third time, and to welcome<br />
2.<br />
situations fraught with danger:yet absolutely without<br />
hazard.<br />
This will be the role of an advanced driving simulator.<br />
which we are studying in the Unitcd States. Technology<br />
will promote the cause of safety only with disciplincd<br />
application, and the simulator may give us that<br />
disciplined approach.<br />
The ultimate henefits appear clearly worth the investment,<br />
an extra half-second's warning of imminent danger<br />
can reduce rear-end and intcrscction crashcs about half:<br />
as well as 30 pcrcent of crashes with oncoming traffic.<br />
Extend the added warning time to a full second, itrrd<br />
approximately 90 percent of the crashes can be avoided.<br />
All of this has relevance for every driver in every nation.<br />
But it perhaps has the particuliu appeal of helping the<br />
older driver. ln the United States the proportion of older<br />
drivers is expanding.<br />
Older drivcrs cxperience known physiological changes<br />
that affect vision and reaction time, for exatnple. But not<br />
at the same rate, and not necessarily at the same age.<br />
Pcrhaps the extent of the driving privilege, carefully<br />
sculpted as to type and range, could virtually be<br />
prescribed for lhe individual, based on demonslrated<br />
capabilitics and limitations.<br />
"Limitations"<br />
is lhc key. Eliminate them, or<br />
compensate for them. How to do that becomes the<br />
research challenge for the 1990's.<br />
Through the <strong>ESV</strong> prism we see car and driver as a<br />
paired cntry on onc sidc of the satety cquation. Solving<br />
for safety inevitatrly requires a melding of car and driver<br />
in a tandem solution. That's what IVHS and simulation<br />
should offer motorists of thc world.<br />
Thcsc <strong>ESV</strong> confcrcnccs in my expcricnce have becn<br />
one of thc most cxccptional information cxchangcs in lhc<br />
aulo safety marketplace. People bring good ideas and<br />
takc away good ideas. They listen.<br />
Very much the opposite of the psychiatrist who at the<br />
end of the day always looked as bright and chccrful as<br />
he did first thing in the tnorning.<br />
A colleague asked him how he coulcl sit hour after<br />
hour listening to all those horrible problems and still<br />
look so good at 5 P.M. The psychiatrist replied:<br />
"Who<br />
listens?"<br />
We have no non-listeners here, and plenty of excellent<br />
talkcrs. I know this will be, as always, a superb<br />
conference.<br />
you to Paris and to thi$ Science and Industry complex,<br />
which I view rs a place ideally suited to your work.<br />
I wish to thank all those who assisted with the<br />
preparations for this conference and who will ensure, in<br />
the days ahead, thflt it procceds smoothly and is a<br />
complete success.<br />
The improvement in the design and equipment of<br />
vehicles clearly constitutes an essential factor for
progress in the area of road safety. For this reason, the<br />
French Government, in conjunction with its EEC<br />
partners, is making a concerted effort to encourage<br />
rescarch in this field and the earliest possible<br />
incorporation of the findings in standard vehicles.<br />
Reducing unsafc road conditions can only bc viewed<br />
today in the context of a comprehensive approach that<br />
takes into account the entire driver-vehicle-trafficinfrastructure<br />
system. Indeed, it is important for<br />
technological innovations to be designed and optimized<br />
based on the road situation and the actual behavior of<br />
users. Therefore, modern communications technology<br />
applied to vehiclcs must permit us to increase<br />
considerably the number of paramcters taken into<br />
account to improve analysis of driving situations and to<br />
ease the burden placed on drivers by the great incrcase<br />
in driver-controlled mechanisms. If one considers all the<br />
parameters that need to be known at all times and all the<br />
functions that the driver must control in real time, it is<br />
clear that he is incapable, in most cmergency situations,<br />
of cvaluating correctly what action to take or how to<br />
handle thc vehicle accordingly. Automatic stecring must<br />
provide a response in these cases of driver failure.<br />
Other than these extremc cases, adapting to real<br />
driving behavior must be an ongoing concern of all<br />
rescarch. The topics addressed at this conference<br />
demonstrate that this approach is now an important area<br />
of interest in your discussions.<br />
Moreover, it is encouraging to note that the research<br />
conductcd in Europe within the framework of the<br />
EUREKA program is beginning to be applied to<br />
experimental vehicles suitable for driving, some of which<br />
will be on display this wcek.<br />
Presentation of Research Policy<br />
A very large number of research projects have bccn<br />
developed in recent years with a view to improving the<br />
safcty of vehicles, such as, in particular, the<br />
PROMETHEUS program, which was started by the<br />
makers of European automobiles within the framework<br />
of EUREKA. Othcrs include the DRIVE program of the<br />
Community and the DRIVE 2 program, which is still<br />
being defined. Lastly, there is the French program<br />
"Safe<br />
Vehicles and Roitd Safety" which the French<br />
Govcrnment has just approved.<br />
The PROMETHEUS progrilm has studied and<br />
developed numetous functions capablc of improving<br />
safety, by warning the drivcr of a possible loss of control<br />
or collision, by providing assistance in difficult<br />
situations, or by improving opportunities for emergency<br />
calls.<br />
An initial phase that demonstrates the technical<br />
feasibility of these different functions has been<br />
completed and European car makers demonstrated these<br />
functions for the lirst time very recently in Turin. The<br />
exposition illustrates these new possibilities, particularly<br />
with respect to PEUGEOT-CITROEN cars.<br />
r Secfion 1: OPenlng Ceremonies<br />
Even more recently, the Commission of the European<br />
Communitics launched<br />
"Drive<br />
a largc-scalc 2" call for<br />
bids for a project to test thc tcchnical feasibility and<br />
public acceptance of new provisions aimed a[ lnore<br />
efficient and safer management of road traffic. The<br />
managcrs of the French infrastructures have, by and<br />
large, responded to this call. The final results arc still<br />
unknown, but we think that several experimcnts<br />
involving urban and inter-urban traffic will be conductcd<br />
in France. The French Governmcnt will fully support<br />
these operations and will carefully follow up on and<br />
evaluate them, with a vicw to determining the most<br />
attractive options and adopting the policies ncccssary for<br />
their implementation. I am pleased that, for the first<br />
time, a technical session is being dcvotcd to this<br />
important matter.<br />
Thc gains to be expected with respcct to primilry<br />
safety should not overshadow the researgh aimed at<br />
improving thc passive safety of vehicles. Progrcss in the<br />
design of structures and the churacteristics ol ntaterials<br />
make it possiblc to improve the protection of occupants<br />
from frontal and lateral impacts. Making optimal use of<br />
protective devices is important. The "COVER"<br />
experimcntal safety vehicle, prescnted by RENAULT,<br />
provides fln cxarnple of new possibililics for the<br />
protection of occupants at speeds of impact highcr than<br />
those tested on the busis of current rcgulations.<br />
The objcctivcs of the new French program cntitled<br />
"Safe<br />
Vehicles and Road Safety," which is based on<br />
more detailed studics on accidents, ate even rlorc<br />
ambitious. State-of-the-art experirnental vchiclcs will<br />
illustrate the actual<br />
possibilities explored by research. Greater compatibility<br />
will be sought bctwcen the different types of vchicles,<br />
with a view to making protection insidc vchicles and<br />
their external damage rcsistancc potential as effective as<br />
possible.<br />
A specific program will be devoted to trucks. The<br />
object is to improve the dynamic stability of lruck-andtrailer<br />
cornbinations and seek ways to rcduce the danage<br />
potential of thc trucks. Finally, research will focus on<br />
socio-econornic questions with a view to better<br />
understanding the role of new technology in rclation to<br />
the real nccds of drivers. I hope that this ncw program<br />
preparcd by PEUGEOT-CITROEN, RENAULT, and<br />
INRETS within thc liamework of PREDIT will lcad to<br />
rapid and concrete results, thcreby cnsuring the<br />
completion of a significant phasc.<br />
This effort, which is quitc cxccptional with respect to<br />
research, will be maintaincd, of course, by important<br />
progrcss in the area of induslrial and regulatory plans<br />
aimed at reducing unsafe road conditittnli in Frlncc.<br />
Industrial and Regulatory Matters<br />
It is theretbre clear that since thc last <strong>ESV</strong> conference,<br />
great progress has been made with rcspcct to research in<br />
all scctors pertaining to road safety, and the scope and<br />
j<br />
j
13th lnternetlonal Technlcal Conterence on Experlmental Satety Vehlcles<br />
variety of the programs already undertaken bode well for<br />
the continuation of this progress. The cffcctive<br />
improvement of safety on our roads is linked to the<br />
application of the findings of this research, which<br />
implies joint action between car makers and public<br />
entities.<br />
I note with interest that, for the first time, matters<br />
pertaining to thc modcrn methods of linkage between the<br />
road and vehicles appear on the program of this<br />
conference. In fact, I believe that in the past, this<br />
conference devoted attention to mfltters linked to passive<br />
safety, while safety involves, first and foremost, an<br />
elfort to avoid accidents.<br />
From this perspective, I think it necessary to address<br />
the question of speed.<br />
There can be no consistent road safety policy without<br />
a policy on speed. This applies to both active and<br />
passive safety. Speed is also an issue in considerations<br />
regarding the emission of pollutants, in particular gases<br />
contributing to the greenhouse effect, and energy<br />
consumption. I therefore think it necessary to define an<br />
international approach to this problem soon and, in the<br />
interest of efficiency, I think that it would be appropriate<br />
to begin with trucks, for which the problem is the most<br />
serious and the solution wcll under way rlt the<br />
international level. In this area, with the electronic<br />
steering systems of Diesel engines, speed limiters thilt<br />
are totally integrated into thc enginc can be envisioned<br />
in thc ncar future. In othcr words, they would be fbolproof,<br />
would ensurc optimal fuel cconomy, and would<br />
minimize polluting cmissions in the actual traffic<br />
conditions of vehicles.<br />
Given this fact, improvements envisioned in the active<br />
safety of vehicles will not succeed in eliminating all road<br />
accidcnts, and it is thcrefore ncccssafy to employ<br />
strategies used for a long time to protect occupants of<br />
vehicles in cases of impact.<br />
In this rcgard, it would be appropriate to build in a<br />
system of protection for occupants in the case of lateral<br />
impacts and to improve the protection of occupants in<br />
the case of frontal impacts.<br />
The formulation of up-to-date regulations on lateral<br />
impacts has bccn long and complex. It was recently<br />
achieved in thc Unitcd States and is in the process of<br />
being succcssfully completed in Europe. It is clearly<br />
desirable for American and Europcan methods to be<br />
harmonized over time, when sufficient expericnce is<br />
gained regarding their application and thc progress that<br />
can reasonably be expected with respect to new models<br />
has been achieved. I am certain that this question will be<br />
one of the most important on the agenda of the<br />
Fourleenth <strong>ESV</strong> <strong>Conf</strong>erence.<br />
For protcction in cases of frontal impact, Europeans<br />
have long believed that seat belts are essential and that<br />
wearing them should be mandatory under all<br />
circumstanccs and whcrcver possiblc. The findings of<br />
studies of actual accidents show that the protection<br />
offered by seat belts is excellent in the case of small<br />
crashcs, vcry good in thc citsc of modcratc crashcs, but<br />
inadequilte in the case of more $erious crashes. For this<br />
reason, numerous innovations have been presented or<br />
will be presented by car makers in the months to come,<br />
with a view to offering added protection. I have in mind<br />
in particular a ncw design of the air bag that is spccially<br />
made for the European market and adapted to small and<br />
mediunr-sized cars,<br />
These quite important technological changes have been<br />
developed spontilneously by car makers. This proves that<br />
safety has become an important marketing feature. The<br />
time has now come to change the regulations, taking into<br />
account these innovations, and to define the adapted<br />
technical and administrative framework that permits<br />
actual safety to be improved with the greatest<br />
international openness.<br />
Therefore. this <strong>Thirteenth</strong> <strong>Int</strong>ernational <strong>ESV</strong><br />
<strong>Conf</strong>erence is opening under the best circumstances, and<br />
I earnestly hope that the work that will be carricd out<br />
this wcck will be as fruitful as it promiscs to bc.
Awards Presentations<br />
Awards for Safety Engineering Bxcellence<br />
Chairman: George L. Parker<br />
<strong>Section</strong> 1: Opening Ceremonies<br />
In recognition of and appreciation for extraordinary contributions in the ficld of motor vehicle safety engineering and<br />
for distinguished service to the motoring public.<br />
Federal Republic of Germany<br />
Josef Haberl<br />
BMW AG<br />
:<br />
Since 1977, Mr. Haberl has been dedicated to improvement<br />
in the area of occupant protection. He was an<br />
essential part in the dcvelopment of the first BMW air<br />
bag system. Mr. Haberl and his department were decisive<br />
in promoting safety devices such as the ergonomic rear<br />
restraint systcm, automatic belt height adjustment, the<br />
seat-integrated belt systcm, and the mechanical belt<br />
pretensioner rcsulting in simplified handling, increased<br />
comfort and ultimately a higher usage rate. All systcnts<br />
have led to a morc efficient restraint function during the<br />
crash and havc contributed to a remarkable increase of<br />
occupant protection in real traffic accidents. Mr. Haberl<br />
is deserving of particular rccognition.<br />
France<br />
Nelson Casadei<br />
Renault<br />
Mr. Casadei has worked in the field of automotive safety<br />
engineering for 22 years. Hc lcads Renault's crash<br />
testing department. Significant contributions have bccn<br />
made in crash precision, reproducibility of tcsts, and<br />
rcsults reliability. Renault has produced three<br />
Experimental Safety Vehicles within the last 20 years<br />
duc to lhe performance of Mr. Casadci and his<br />
cnginecring group. For Mr. Casadei's contributions and<br />
that of his engineers in the field of crash test<br />
methodology, special recognition is given.<br />
Dr. Dimitrios Kallieris<br />
University of Heidelberg<br />
Dr. Kallieris has been associated with rhe Institute of Forensic<br />
Medicinc at the University of Heidelbcrg since<br />
1969. His early research efforts included quantification<br />
of the mechanical loading and failure characteristics of<br />
a variety of human tissucs as well as the developmcnt<br />
and conslruction of an automotive crash simullrtion<br />
facility at the Institute. Dr. Kallicris has conducted nrore<br />
than three hundred biomechanical impacts using the<br />
lnstitute's crash sinrulation facility investigating the<br />
human irutomobile occupant's interaction with a variety<br />
of restraint systcms in frontal impacts, the quantification<br />
of response and injury of humans in side impacts, and<br />
the impact response of pedestrians during vehicular<br />
collisions. For all his cfforts, Dr. Kallieris is recogniz.cd.<br />
Jean DeRampe<br />
Peugeot Sa<br />
Mr. DeRampe's commitment to automotive safety enginccring<br />
has been clearly demonstratcd since 1972, when<br />
he tregan work for Pcugcol 10 develop occupant protcction<br />
in side impact crashcs. His work has taken hirtt ittto<br />
the ficld of passive restraint systems for rcar seat occupants.<br />
He has also shown it is possible to build a small,<br />
fuel efficicnt car while protecting occupants and<br />
pedestrians. Mr. f)erampe is deserving o[ special<br />
rccognition for these occupant protection<br />
accomplishments.<br />
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lSth <strong>Int</strong>ernatlonal Technlcal <strong>Conf</strong>erence on Experimental Safety Vehicles<br />
Francis Ferrandez<br />
INRET'S<br />
Mr. Ferrandez has contributed to the development of a<br />
"diagnosis<br />
analysis" method focusing on how an accident<br />
happened and explaining its occurrence and severity. He<br />
is also responsible for a more comprehensive procedure<br />
involving the analysis of accident mcchanisms<br />
specifically dcaling with primary safety and covering<br />
various aspects of the driver/vehicle/road system. For his<br />
contributions to vchicle safcty, Mr. Ferrandez is<br />
recosnized.<br />
Italy<br />
Dr. Ing. Paolo Scolari<br />
Fiat Auto S.p.A<br />
Dr. Scolari has becn responsible for Fiat Auto<br />
Enginccring since 1970. Dr. Scolari manages and<br />
coordinatcs all research/development and design<br />
activities concerning new company modcls, paying<br />
particular attention to both active and passivc safety. In<br />
Japan<br />
Namio lrie<br />
Nissan Motor Co., Ltd.<br />
Mr. Irie is a pioneer in vehicle safety research and<br />
development of advanced chassis technology for Nissan.<br />
In l97l hc was in charge of Nissan's <strong>ESV</strong> program for<br />
vehicle layout planning, as well as the R&D activities<br />
concerning seat belt and air bag occupant protection<br />
systems. Subsequently, in the development of a safcty<br />
concept car, he was insttumental in advancing research<br />
in vehicle handling and safety, and the driver-vehicle<br />
system from the standpoint of crash avoidance safety.<br />
Through this work he played a key role in cstablishing<br />
basic foundations for research in vehicle dynamics. In<br />
addition he has also been vigorously involved in research<br />
on active chassis control, bringing about major<br />
innovations in vehiclc safety pcrformancc. Wc acknowledge<br />
Mr. Irie's outstanding achievement$.<br />
Yutaka Kondo<br />
Toyota Motor Colporation<br />
Mr. Kondo has been actively involved in research and<br />
development of vehicle safety technology since 1963. In<br />
197'7 , he made a major contribution to the devclopment<br />
Michel Kozyreff<br />
Electrolux Autoliv<br />
Mr. Kozyreff has carried out numerous research and<br />
feasibility studies involving safety belts and air bags for<br />
frontal and side impacts. All safety rcstraint systems<br />
recently installed in motor vehicles by French car makers<br />
wcrc dcvclopcd by Mr. Kozyrcff and his R&D tcam. Mr.<br />
Kozyreff has strongly supported the air bag concept<br />
among French motor vehicle manufacturers since I985.<br />
He has been an active supporter of the Eurobag.<br />
Recognition is given Mr. Kozyreff for his overall<br />
contributions in the area of sat'ety restraints.<br />
addition, he has givcn unrelcntless dedication to the<br />
safcty of motor vchicles in the area of small size and<br />
weight. Dr. Scolari is recognized for his varied<br />
contributions to ilutomotive enginccring safcty.<br />
of the Duplex Emergency Locking Retractor System for<br />
safcty belts and has bcen especially active in the<br />
developmenf of air bag.s. He displayed outstanding<br />
leadership in organizing a consortium of manufircturcrs<br />
for the technical development and merchandising of air<br />
bags. He was a major contributor to the electronic air<br />
bag system on the 1989 Lexus LS 400, the first air bag<br />
to be fldapted to a tilt and telescopic steering column.<br />
Mr. Kondo is deserving of this spccial rccognition.<br />
Katsumi Oka<br />
Honda R&D Co., Ltcl.<br />
Mr. Oka is recognized for his contributions to the<br />
improvement of crashworthincss of Honda production<br />
cars, especially in the body structurc. One of his<br />
achievements is the establishment of the body structure<br />
for small and light vehicles with excellent crash<br />
performance at a speed of 35 mph. Mr. Oka has actively<br />
promoted the dcvclopment of unique occupant protection<br />
devices such as the Honda Pretensioner and Honda's<br />
passenger side air bag. He leads the development oI an<br />
all aluminum vehicle body structure which is crashworthy.<br />
Through his many achievements, Mr. Oka has<br />
contributed greatly to the improvement of automotive<br />
safcty.
The Netherlands<br />
Prof. Ilr. Jac'Wismans<br />
TNO Road-Vehicles Research Institute<br />
Since 1978, Dr. Wismans has worked in the field of<br />
injury biomechanics and passive traffic safety at the<br />
TNO-Road Vehiclcs Research Institute. Dr. Wismans<br />
actively promotes the contribution of injury prevention<br />
by the improvemcnt of safety in road traffic and he<br />
supports intcrnational cooperation in these fields. He has<br />
been a strons motivator of the use of mathematical sim-<br />
Sweden<br />
Magnus Koch<br />
Volvo<br />
Mr. Koch is Principal Scientist at the Volvo Automotive<br />
Safety Center. His work covers a diversity of disciplines<br />
such as vehicle test transducer and measurement systems<br />
technology, computcr applications for test data<br />
acquisition, stereo photogrammetry, crash test dummy<br />
development and usc, test data evaluation and<br />
experimental statistics. His work and knowlcdge have<br />
been instrumental in the developrnent of scveral ISO<br />
Standards and the development of a crash recordcr for<br />
installation in cars. He has been menlor for a numbcr of<br />
students from Chalmers University of Technology who<br />
do projects or thesis work in the industry, increasing the<br />
awareness of safety technology at the enginecring<br />
schools ultimately benefiting automotive vehicle safety.<br />
Mr. Koch is to be commended for his dcdication to<br />
furthering the advancement of motor vehicle safcty.<br />
United States<br />
Dr. Priya Prasad<br />
Ford Motor Cornpany<br />
Dr. Prasad has accomplished significant engineering<br />
research. Dr. Prasad pioneered extensive spinal research<br />
which is prescntly uscd in the designs of aircrirft ejection<br />
seats and vehicle occupant restraint systems. He has<br />
conducted important research on hcad injuries resulting<br />
in formulating the risk of head injury as a function of lhe<br />
Head Injury Criteria (HIC). He conducted pioneering<br />
research on the injury potential of out of position<br />
occupants during air bag dcployment. Dr. Prasad has<br />
analyzed a number of structural math modcls which,<br />
<strong>Section</strong> 1: Openlng Ceremonles<br />
ulation in injury prevention research. Under his<br />
supervision the MADYMO crash victim sinrulation<br />
program has been dcvcloped into a successful research<br />
and dcvelopment tool, which is now used worldwide by<br />
rescarch institutcs. manufacturers and other orsanizations.<br />
Olle Nordstrom<br />
Swedish Road and Traffic Research lnstitute<br />
Since 1960 Mr. Nordstrom has been involved in research<br />
at the Swedish Road and Traffic Rcscarch Institute<br />
dealing with vehicle dynamics, brakcs, and lircs. Hc has<br />
been responsible for rnany studics on braliing and<br />
handling over the yeius including reseiuch on the braking<br />
and handling performance of car/trailcr combinations,<br />
antilock braking performance, influence of tlrale<br />
imbalance on performance stahility of heavy vehicle<br />
combinations and heavy vehicle antilock brahing<br />
performance. Much of his work resulted in proposed or<br />
adopted regulations.<br />
Mr. Nordstrom wirs also involved in the Swedish RSV<br />
program. Mr. Nordstrom was project manager for the<br />
construction of a large test facility at VTI for testing<br />
steering rnd braking characteristics of truck and<br />
passcngor car tires, especially on ice. For his<br />
contributions to motor vehicle safety over a long period<br />
of ycars, Mr. Nordstrom is deserving of special<br />
recognition.<br />
have led the worldwide auto industry to adopt<br />
standardized data sels tbr modeling crash test dummies<br />
and havc also rcsultcd in improvcmcnts to publicly<br />
available crash silnulation software.<br />
Ronald S. Zarowitz<br />
Chrysler Corporation<br />
Mr. Zarowitz conceived and managcd Chryslcr's<br />
<strong>Int</strong>cgratcd Child Scat program working with cnginccrs<br />
Matthcw E. Dukatz, Fred C. Kresky, Jel'frey T. Lambert,<br />
James P. Lezotte, Robert W. Murphy, arrd George S.<br />
Popa, who werc responsible for the design and execution<br />
"!s<br />
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lSth lnternatlonel Technlcal Conlerence on Experlmentel Sefety Vehlcles<br />
of this major advance in child restraints, which is<br />
expected to set a world-wide trend among automobile<br />
manufacturer's. The <strong>Int</strong>egrated Child Seat represents a<br />
significant improvement in providing a convenient and<br />
effective child restraint system, which will increase<br />
Special Awards of Appreciation<br />
usage and benefit thousands of children and their<br />
parcnts. Mr. Zarowitz and his team of cxpcrts are<br />
commended for their advancement of child restraint<br />
occupant protection.<br />
In recognition of and appreciation for outstanding leadership and extraordinary contributions in the field of motor<br />
vehicle safety.<br />
United States<br />
Dr. Leonard Evans<br />
General Motors<br />
Dr. Evans as a research scientist has contributed significantly<br />
to the understanding of factors influencing<br />
automotive safety. During thc 1970s hc conducted<br />
pioneering observational rcscarch on drivcr risk-taking<br />
by vehicle following distances and with safety belt use.<br />
In the 1980s he developed methods of crash data analysis<br />
that have objectively quantified the life-saving<br />
effectiveness of occupant restraints, the importance of<br />
vehicle mass and seating position, and relative risk<br />
differences due to occupant age, gender and alcohol use.<br />
Dr. Evans' research is internationally respected.<br />
Karl-Heinz Faber<br />
Mercedes-Benz of North America. Inc.<br />
Mr. Faber has played a key role in bringing to the United<br />
States market significant safety features such as the Mercedes-Bcnz<br />
Supplemental Restraint System and Anti-lock<br />
Brakes as standard equipment, as well as l.he industry's<br />
first automatic rollover bar for convertibles. He has<br />
championed programs to promote Europe's<br />
PROMETHEUS highway safety project and did pioneer<br />
work in bringing about cooperation between that program<br />
and the emerging U.S. <strong>Int</strong>elligent Vehicle/Highway<br />
Systems initiatives. For these and numerous other<br />
contributions to motor vehicle safety and for his<br />
outstanding managcrial leadership in this ficld Mr. Faber<br />
is especially recognized.
<strong>Section</strong> 2<br />
Government Status RePorts<br />
Chairman: Howard M' Smolkin, United States<br />
Commission of the Buropean Communities<br />
and those concerning speed limiters for commercial<br />
Daniel Verdiani<br />
vehicles and buses, hitching devices for tow trucks' and<br />
Directeur General<br />
commercial vehicle cabins, ilre irt il fairly advanced stagc<br />
Direction and Generale III<br />
. in the Community decision-making process'<br />
Existing special guidelines are updated on a rcgular<br />
<strong>Int</strong>roduction<br />
basis in accordance with technical progress achieved in<br />
Mr. Chairman:<br />
this field, to en$ure the high lcvcl of protcction rcquircd'<br />
I wish to thank you, on behalf of the Commission of Sincc thc last <strong>ESV</strong> <strong>Conf</strong>crcncc, amendments have<br />
the European Communities, for the invitation to submit been incorporatcd into the rcquirements of thc Direstives<br />
to this conference the activity report of the European on Brcaking; installation of scat belts; conduct of the<br />
Community on motor vehicle safety.<br />
steering meihanism upon impact; the rear field of vision;<br />
We are grateful for this opportunity to report' to this and the lateral protection of comtnercial vehicles'<br />
unique gathcring of cxpcrts from thc world over, on the To supplemcnt rhc Comnrunity rcgulations in the area<br />
aclrle"ements and the future goals of the various of medium-term vehicle safety, the Commission is<br />
Community policies affecting the improvement of working on several projccts; I shall mention only two of<br />
highway safcty. Thesc arcfls of conccrn are basically our them, wtrictr shall be the subject of reports submittcd<br />
piiry with regard to completing the internal market' and during this <strong>Conf</strong>erence: the protection of the most<br />
our transportation PolicY<br />
vulncrablc scgment of thc road uscr population; and the<br />
protection of vehicle occupants in case of lateral impact'<br />
EEC Motor Vehicle TYPe-APProvnl<br />
The Commission relies essentially on two appro'lches<br />
As you know, the number one European Community when it establishes the technical bases for its Directives'<br />
objectlve is the completion of its internal market' in Firsr. it obtains the cxpertise availablc itr the tnentber<br />
order to ensure the free circulation of persons, goods' States and from the spccialized agencics, industry and<br />
capital, and services.<br />
consumer organizations, particulfirly wilh thc assistance<br />
In thc motor vehicle sector, this task will be of groups of experts in which all fields are represented'<br />
implemented by establishing the EEC motor vehicle such as the group that has eartred a reputation' even<br />
type-flpproval system, which is scheduled to become within rhe EEC, under the ilctonym<br />
operationat on January l, 1993, and become mandatory'<br />
uit". u three-year trial period, beginning in 1996' for any<br />
new typo of vehicle sold in the Community'<br />
Asiae from its economic impact' the EEC typcapproval<br />
will at the samc time contribute significflntly to<br />
th" improuement of rtot only road safety, but of the<br />
environment as well. Indecd, thc 1985 Singlc Act<br />
requires that the Commission establish a high level of<br />
protcction as the bnsis for its proposals on the<br />
-harmonization<br />
of mcntber'slate laws on health' safety'<br />
and cnvironmcntal Protcction.<br />
Full harmonization will ensure that the strict technical<br />
standards sct forth in the Special Directives for the typeapproval<br />
procedure will be applied throughout the<br />
member Smtes without excePtion.<br />
Most of the Special Directives that are a part of this<br />
typc-approval procedurc have been adopted' Those<br />
tliatittg to tires, satcty glass, weight, and dimensions'<br />
"ERGA-Safety"'<br />
In addition, the Contrnission initiatcs, as necessary'<br />
specific research progralns which it usually coordinates<br />
and, to e greflt extent, fitratrccs'<br />
One suih program was called "BIOMECANIQUE"<br />
(1978-82), which was followed by a program to develop<br />
the "EUROSID" testing dummy, completed in December<br />
1986.<br />
More recently, we participated in an international<br />
research progrilm on intproved protcction of vulncrrble<br />
users, p"d*ttrious and cyclists, from impact with<br />
aututubil*t, and wc arc prcparing to join an<br />
international progrum to compilre vitrious options with<br />
rcgard to latcral impact tcsting to ensure coordination<br />
and evaluation of results.<br />
Transportation PolicY<br />
In addition to the regulations on vehicle manufacturing,<br />
the Clommunity is making, lnd will continue to
13th lnternetional Technlcal <strong>Conf</strong>erence on Experlmental Safety Vehicles<br />
make, an even greater conFibution towards improving<br />
highway safety through its transportntion policy.<br />
The Community institutions, its Parliament, Council,<br />
and Commission, confirmed in a 1985 resolution that<br />
road safety was an essential aspect ofEEC transportation<br />
policy. And let us not forget that 1986 was proclaimcd<br />
European Highway Safety Year.<br />
Important accomplishments cither made or proposed<br />
under this policy include Community guidelines in the<br />
following areas, among others:<br />
. weight and dimension of commercial vehicles;<br />
. Europcan driver's license;<br />
. periodic inspection of vehicles in service;<br />
. limiting thc speed of commercial vehicles;<br />
. wearing of seat belts;<br />
. measures against drunk driving.<br />
Furthermore, this policy allows the Community to<br />
promote research projects such as the creation of a<br />
European data base on highway accidents, not to mention<br />
the "DRIVE" and "PROMETHEUS" programs that<br />
should contribute significantly to the improvement of<br />
road safety.<br />
ln order to ensure a foundation for future road safety<br />
efforts, the Commission rcccntly asked a group of highlevel<br />
experts to draft a report identifying areas of<br />
necessary and feasible Community action. This rcport<br />
contains numerous suggestions on mcasures that can be<br />
taken with respect to both vchicle construction and road<br />
traffic. On thc basis of this report, the Commission will<br />
draft appropriatc proposals and submit them in due time<br />
to the Council and lhe Parliament.<br />
Relations between the EEC and Other<br />
<strong>Int</strong>ernational Organizations<br />
I cannot conclude my report, Mr. Chairman, without<br />
mentioning the Community's relations with other international<br />
organizations in the area of safcty regulations.<br />
Although our priorities arc focused on the internal<br />
market, we do not ignore the broader context which<br />
efforts to improvc safety both require and deserve.<br />
Germany<br />
Karl-Friedrich Ditsch<br />
Ministry of Transport<br />
Twelve years ago the 7th <strong>ESV</strong> <strong>Conf</strong>erence was held in<br />
Paris. On this present occasion, too, wc were pleased to<br />
acccpt thc kind invitation of the French Governmcnt to<br />
come to Paris, and I am piuticularly honourcd to prescnt<br />
my government's $tatus report for the l3th <strong>Conf</strong>erence.<br />
The Uniflcation of Germany<br />
Since the last <strong>ESV</strong> Conl'crence, the chief political<br />
event for the Federal Republic was the unification of the<br />
10<br />
The Chairman of the European Experimental Vehicle<br />
Committee has just referred to thc exccllent cooperation<br />
that has existed bclween the Commission and this<br />
important scientific institution since its creation.<br />
The above-mentioned Commiltcc has successfully<br />
counseled us in our establishment and scientific<br />
managcmcnt ot the BIOMECANIQUE and EUROSID<br />
programs. I hope that such cooperation will continue and<br />
increase when it bccomes necessary to establish highly<br />
technical international regulations such as those<br />
regarding the performance o[ vchicles when subjected to<br />
frontal and lateral impacts.<br />
The Unitcd Nations Economic Commission for Europe<br />
in Geneva is for us the ideal forum for comparing the<br />
experiences of lawmakers and industrialists rcprcscnting<br />
thc world's economic blocs.<br />
The Commission is an active participant in the work<br />
of group of experts WP 29, which keeps it informed on<br />
its own activities, and will also participate as necessary<br />
in thc study programs initiated by WP 29, such as the<br />
program on the lateral impact tcst.<br />
In this perspective, we hopc that the revision of the<br />
1958 Agreernent will allow the European Community to<br />
accede to it as it is, and that this Agreement will be open<br />
to all countries throughout Ihe world interested in vehiclc<br />
safety.<br />
Finally, I should likc to mention the European<br />
Economic Space, which as you know was the subject of<br />
a recent agreement betwccn the Community and the<br />
European Free Trade Association, and which will soon<br />
make it possiblc to unite these two economic blocs in the<br />
area of interest to us hcrc, among others.<br />
Conclusions<br />
Mr. Chairman, I hope that I have succeeded in<br />
providing to this csteemed <strong>Conf</strong>erence, to which I offer<br />
every wish for deserving success, a comprehensive<br />
overview of the activities of the European Community in<br />
this domain.<br />
Thank vou for Your attention.<br />
country on 3 October 1990. On this date the German<br />
Democratic Rcpuhlic became an integral part of the<br />
Fcdcral Republic of Germany. Federal German law also<br />
came into force in thc former German Democratic<br />
Republic at this time. Exceptions and transitional<br />
flrrflngements havc been introduced to alleviate the<br />
problcrns which this event was expected to create. A<br />
numbcr of transitional arrangernents have also been<br />
introduccd in the field of road traffic. Different<br />
regulations apply for instance to maximum spccds on<br />
motorways (100 km/h/130 km/h recomtncnded speed)<br />
and other roads in non-built-up areas (tlO km/h/100
km/h). There will also be a differcnce in the maximum<br />
permissible blood alcohol content (0 mg/80 mg per lff)<br />
ml) for a transitional period. Onc factor of importance to<br />
the vehicle owner is the fact that ir number of vehicles<br />
will need to be retrofitted with rear seat belts. hazard<br />
warning systems and uniform tyres before their general<br />
inspection. Warning triangles and first aid kits will also<br />
have to be carried. The Regulations Govcrning Third<br />
Party Motor Insurancc flnd thc Act Governing Motor<br />
Vehicle Tax have also been in force since the start of the<br />
year.<br />
Legislation Governing Road Traffic<br />
The trial introduction of 30 km/h zones which was<br />
outlined in the Federal Government's last status report<br />
and which was intended to increase road safety has<br />
proven successful, the appropriate provisions for such<br />
being incorporated into thc German Road Traffic Regulations<br />
on I January 1990. Numerous towns and cities<br />
have since introduced 30 kmlh zoncs in rcsidcntial areas<br />
lying outside networks of major roads, Iegal regulations<br />
often being accompanied by structural measures. Sinrilarly<br />
"traffic-restraint" zones can now be established in<br />
commercial sectors and spccd limits of less than 30 km/h<br />
can be imposed. Such stcps are envisaged in particular<br />
for areas of historical interest in order to kecp the<br />
number of traffic signs at an acceptable level.<br />
The last status report also outlined a -'fewer traffic<br />
signs" model, and this has now been successfully concluded.<br />
As a result of this work, a new guideline has<br />
been drawn up by the Federal Ministry of Transport<br />
which is intended to assist municipalities and local<br />
authorities in improving the marking of roads. The<br />
measures are directed in thc main at reducing road<br />
marking for stationary traffic and at improving<br />
signposting.<br />
The Ordinance Governing the Transport of Hazardous<br />
Goods by Road has been improved following a scrious<br />
tanker truck accident in Herhorn in 1987. In an effort to<br />
enhance active safety, thc brakc systems of heavy<br />
vehicles carrying hazardous goods must, as o[ this year,<br />
be fitted with an anti-locking system (ALS), automatic<br />
adjusters for brake lining wcar and heavy-duty retiuder<br />
systcms which function independently of the service<br />
brake. The Federal Governnrent is itlso looking to anchor<br />
these requirements in the European Agreement<br />
Concerning the Carriage of Hazardous Goods by Road<br />
which applies for international traffic.<br />
Buses are still the safest form of transport for their<br />
passengers. The automobile industry has helped to revise<br />
the ECE regulations and to incorporate them into EC<br />
legislation. It was possible for the most part to adopt the<br />
regulations applicablc in the Federal Republic for poweroperated<br />
and automatic passenger doors. Further EC<br />
directives for buses will incorporate rcgulations<br />
Sovcrning the strcngth of seats and seat anchorages and<br />
the fire behaviour of materials used in the passcngcr<br />
Sectlon 2: Governmenf Sfatus Rapofts<br />
compaftment. The German Vehicle Code also states that<br />
bus passengers can only be transportcd lying down if<br />
they are adequatcly protected by rcstraining dcviccs.<br />
Changes to road traffic legislation involvcd changes to<br />
individual provisions of the Vehicle Code and adaption<br />
of national regulations to EC directivcs and ECE<br />
regulations. Particularly worthy of mcntion arc the<br />
change in the maximum permissible length of semitrailers<br />
to 16.5 m, changes in certain axle lttacls and<br />
laden weights, fitting of certlin vehicles with latcral<br />
protectors including obligatory rctrofitting of vehicles<br />
already on the road, an obligation on thc part of other<br />
vehicles to fit wide-anglc rcar-vicw mirrors and<br />
additional lamp mirrors and to incrcase the minimum<br />
tyre tread to I.6 mm.<br />
Accident Statistics<br />
An examination of accident trends must make a<br />
dislinction bctween the area of the Federal Republic<br />
before 3 October 1990 and that of the five new federal<br />
stiltes.<br />
In the Fecleral Republic as it existed prior to this date<br />
the number of road traffic accidcnts over the period 1988<br />
to 1990 remained virtually unchangcd at around 2<br />
million. This must be seen lgainst an increme in vchicle<br />
travel of 87o.<br />
The number of road fatalities has fallen by morc than<br />
a half since 1970 while the number o[ vchiclcs on the<br />
road has increased frorn l8 to 37 million over the same<br />
period and vehiclc trtvcl by 977o.<br />
The numbcr of fatalities attributable to road accidents<br />
in thc Federal Republic (excluding the new federal states<br />
and Berlin (East)) came to approx. 8,200 in 1988 and<br />
roughly 8,000 in 1989. The total of approx. 7,900<br />
fatalities in 1990 represents the lowest figurc sincc l9-53.<br />
The number of passenger cilr occupants killed of roughly<br />
4,500 in 1990 was about as high as it had becn in 1988.<br />
The corresponding figure for 1989 was around 4,3-50.<br />
Thc rcncwcd incrcasc is probably attributable to the<br />
opening up of the inner-German border.<br />
Accident trends in thc fivc ncw fcdcral states need to<br />
be examined separately after Germln unification in<br />
October 1990. Sonrc 1,600 filtfllitics were registered on<br />
this territory in 1988 and around 1,1J00 in 1989. This<br />
figure for 1990 climbed to approx. 3,150. Compared with<br />
the year before (roughly 600 passenger car occupant<br />
fatalities), the number of cur occupants killed almost<br />
increased threefold in 1990. There are rnany rcasons for<br />
thc rise in fatalities in the new federal statcs: an<br />
enormous increase in mobility, a large growth in the<br />
number of (what wcrc by lormer standards) high-power<br />
vehicles on the road, a substantial increase in the number<br />
of inexperienced drivers, particularly younger- generation<br />
drivers, the change in social values and the removal of<br />
intensive police traffic monitoring, inadequate traffic<br />
infrastructure (in terms of both structural and safety<br />
aspects), etc.<br />
ll
lSth <strong>Int</strong>ernatlonal Technlcal <strong>Conf</strong>erence on Experlmentel Sefety Vehtcles<br />
Accident Research<br />
The activities of the Federal Government, the automobile<br />
industry and motor insurance companies are once<br />
again prominent in the field of accident research. The<br />
efforts and advice to improve rear signalling, particularly<br />
as regards increased conspicuousness of braking signals,<br />
havc been continued. Important aspects currently under<br />
discussion include increasing the light intensity,<br />
prohibiting combined tail and brake lights, a possible<br />
minimum distance of 100 mm bctween the two signal<br />
lighting areas and the fitting of a third central brake<br />
light. A braking prewarning system is currently being<br />
discussed which will give an earlier warning of a braking<br />
vehicle.<br />
Headlight systems have seen continuous improvement<br />
over recent years. Systems employing electric discharge<br />
lamps are in the process of being tested.<br />
Additional lateral turn indicators to protect cyclists<br />
when heavy vehiclcs are turning off are to be employcd<br />
for both new and existing vchiclcs with a maximum<br />
design speed exceeding 32 km/h and a length of more<br />
than 6 m. The Federal Govcrnmcnt is endeavouring to<br />
bring about a uniform solution throughout the EC.<br />
As regards govcrnmental accident research, a number<br />
of projects have bcen performed in close cooperation<br />
betwccn govcrnment agencies, the automobile industry<br />
and other research bodies.<br />
At-the-scene accident investigations have been<br />
continued using the modified random sampling method<br />
described at the last conference. Special analyses of<br />
these data have been pcrformed e.g. for assessing the<br />
effectiveness of head rests, for designing a pedestrianfriendly<br />
vchiclc front, for analyzing injuries to vehicle<br />
occupants wearing seat belts and for assessing the<br />
effectiveness of individual sets of measures envisaged in<br />
the PROMETHEUS Programme.<br />
The Federal Ministry of Research and Technology<br />
(BMFT) continues to lend support to research and<br />
development projects designcd at improving passive and<br />
active safety.<br />
The EUREKA project PROMETI{EUS continues to<br />
form a pivotal point of the promotional activity.<br />
PROMETHEUS is concentrating its efforts on developing<br />
intelligent systems to assist drivers. In addition to<br />
such aspects as environmental considcrations and the<br />
reduction of transport costs, the primary goal is to<br />
achicve an increase in active safety.<br />
The necessary studies are being performed in the main<br />
using the PRO-GEN scientific subprogramme. A PRO-<br />
GEN safety group has been set up to satisfy the high<br />
demands placed on safety in the PROMETHEUS project.<br />
Primary areas of activity to date have includcd the<br />
drafting of a safety check list and studies into the<br />
influence which the PROMETHEUS functions have on<br />
safcty. Rcports on thesc topics will he presented in the<br />
technical sessions.<br />
Trials of the ALI-Scout route guidance and information<br />
system (project named: "LISB-Leit und Informationssystem<br />
Berlin") under real traffic conditions in<br />
Berlin ended in March 1991. These trials were intended<br />
primarily to demonstrate the technical feasibility and<br />
operability of thc system, its acceptance by drivers, the<br />
benefits for traffic tcchnology and its cost-effectiveness.<br />
The effects of route guidance recommcndations on<br />
local and non-local drivers are also being dealt with.<br />
This is intcnded to ensure that indicators inside the<br />
vchicle in no way result in any reduction in the lcvsl of<br />
safety.<br />
As regards the safcty aspects of transporting hazardous<br />
goods, the succcssful completion of the development<br />
work and trial testing of the TOPAS safety tirnker truck<br />
has seen a consistent continrration of the BMFT's<br />
promotional policy in the form of the THESEUS project<br />
(Tanktahrzcug mit hochst erreichbarer Sicherheit durch<br />
experimentelle Unfallsimulation = Tanker truck with<br />
maximum safcty attained through experimental acsident<br />
simulation). The results of TOPAS were reported in<br />
detail at the last <strong>ESV</strong> <strong>Conf</strong>erence.<br />
A primary aim of THESEUS is to examine thc safety<br />
of the tanker truck in its entirety, its individual<br />
components and safety deviccs, the types of accident it<br />
is involved in and the other road users it is involvcd in<br />
accidents with. For the first Lime, sysLcmatic and<br />
reproducible studies will analyze the safety standard of<br />
different vehiclc dcsigns and concepts and enable these<br />
to bc cvaluated. The trials revolve around systematic and<br />
reproducible crash tests between tankcr trucks and other<br />
trucks. This is an area about which there is still little<br />
known worldwide.<br />
The results of the studies will make a vital contribution<br />
to increasing the safety of transporting hazardous<br />
goods by road, and in particular to providing new<br />
infbrmation on the requirements on such vehicles which<br />
are essential in safcty tcrms and advisable frotn an<br />
economic standpoint. The project may also be able to<br />
demonstrale the safety benefits of special design<br />
structures. Further details of this projcct and its current<br />
status will be given in onc of thc technical sessions.<br />
The safety of today's coaches has been analyzed in<br />
the SMARAKD project (Sicherheitsmassnahrnen nm<br />
Reisebus an kritischen Details - Safety measures relating<br />
to critical details of coaches). Thc study, which has now<br />
been concluded, made a detailcd cxamination of all<br />
factors inllucncing the safety of buses. By perforrning<br />
detailed, unilorm analysis and evaluation of various<br />
accident surveys, it has been possible to make a<br />
contribution to thc dcvclopmcnt of new and improved<br />
safcty conccpts lor coaches.<br />
The Federal Ministry of Transport has continucd its<br />
extensive research work in all fields. The Federal<br />
Highway Research Institute (BASI) is playing a major<br />
part in this work.
The ECE and EC have drafted a test method which is<br />
designed at protecting the occupants of passenger cars in<br />
the event of a lateral collision. This tcst method, which<br />
employs a full-scale vehicle test, has been the subject of<br />
numerous reports. Efforts are currently undcr way to<br />
dctcrmine whether the composite test method, which is<br />
proposed by industry and takes the form of a computeraided<br />
laboratory tcst, is equivalcnt to thc intcgrated<br />
impact tcst.<br />
The Federal Highway Research Institute is<br />
participating in crash tests as dcfincd by Amcrican<br />
Standflrd ?,14 in order to determine whether the<br />
EUROSID dummy is an equivalent altcrnativc to thc SID<br />
dummy for usc in the latcral impacl test. Thc EEVC is<br />
presenting thrcc rcports on this subject in the technical<br />
seminars at this conference.<br />
As reported at the last <strong>ESV</strong> <strong>Conf</strong>erence, the EC has<br />
supported a research project for developing a test mcthod<br />
for pedestrian protection. Within this international<br />
project, the Federal Highway Research Institute was<br />
assigned the task of analyzing contact between the head<br />
and the front hood. Since the biomechanical basis for<br />
drawing up a test method was insufficient, appropriate<br />
tcsts wcrc initiated which had the specific goal of<br />
resolving this problem and which will be u.sed for future<br />
test series with a hydraulic impact device. A separate<br />
rcport will be given at this conference on the expanded<br />
proposal.<br />
The studies to determine the influence of corrosion on<br />
the changed behavior during impact have been continucd.<br />
The structural behaviour is currently being examincd<br />
using vehicle types which are 5 to 6 years old and which<br />
have undergone modern series anti-corrosion treatment.<br />
In conjunction with the automobile industry and the<br />
Technical Inspection Agency Rhineland (TUV<br />
Rhineland), the Federal Highway Research Institute has,<br />
for the time being, completed its work on a draft EC<br />
directive to protect belted occupants of passenger cars on<br />
impact with the steering wheel. Valucs of 809/3ms and<br />
a maximum accclcration of 120 I were taken as criteria<br />
for assessing a rigid hcad impacter. These values arc also<br />
containcd in a proposal for changing the ECE regulation<br />
No. 12. This work is to be continucd as soon as future<br />
efforts are undertaken to develop a method involving a<br />
deformable impacter in which prcssure pcr unit of area<br />
appears a suitable criterion.<br />
A thorough cxamination has begun to determine the<br />
influence of the impact speed on the dummy loads in a<br />
frontal impact. Small, mid-size and large cars are being<br />
examined at five different impact speeds ranging from 30<br />
to 55 km/h. The influence of this speed tends ro increase<br />
as a linear - rather than a quadratic - function of the<br />
dummy load. Thc rcsults will bc rcportcd at this<br />
conference.<br />
Although purchasers can refer to easily understandable<br />
critcria for most requircments, e.g. cost-effectiveness,<br />
which cars have to meet, this is not yet the cuse with<br />
Sectlon 2: Government Stetus Eeports<br />
safety aspects. A research project into assessing the<br />
passivc safety of vehicles has now been completed and<br />
an initial proposal made for an appropriate method of<br />
procedure. A characteristic fcature of this work is the<br />
linkage between an intensive accident analysis and the<br />
biomechanical interpretation of the physical values<br />
mcasurcd in thc cxperiment.<br />
Charactcristic tests have been conducted for the<br />
planncd further development of ECE regulatirln No. 22<br />
(protective helmets). None of the nine helmet types<br />
testcd satisficd all aspccts of the current testing<br />
conditions at a speed of 35 km/h. Attainable limit<br />
conditions for the applicable limit valucs are given at<br />
impact speeds of up to 30 km/h. Further research work<br />
extends to drafting a test method for the helmet chin<br />
guard. Work is currently being conducted on a national<br />
DIN standard for the purpose of testing protective<br />
clothing for motorcyclists. Thc CEN (Comite Europcen<br />
de Normalisation) is also draftinB a regulation for testing<br />
helmets for cyclists.<br />
The Federal Highway Research Institute has conducted<br />
studies into the behaviour of wheel-chairs in braked<br />
meilns of transportation. These studies have revealed that<br />
wheel-chairs tilt over or slide at deceleration levels<br />
exceeding approxinrately 2m/s2. Proposals for improving<br />
restraint systcms for whccl-chairs and wheel-chair uscrs<br />
travelling in transport systems f'or the disabled have been<br />
drawn up on the basis of impact tests. A number of<br />
qucstions are yct to bc resolved in order to ensure the<br />
safe transport of disilbled persons in modern low-level<br />
buses, e.B. thc most appropriatc positioning in the bus<br />
(either in forward or rcarward facing position). Thcse<br />
buses are currently being analyzed under normal<br />
conditions of operation to obtain data on longitudinal and<br />
transverse decelerations.<br />
I will now look at only a small sclcctiorr of rcscarch<br />
activities which havc been initiatcd spccil'ically l'or the<br />
further development of existing rules and rcgulations.<br />
A projcct to drrl't the requirements which molorcycle<br />
brakes with anti-blocking systems have to satisfy,<br />
particularly as regards braking on curyes, has now bccn<br />
concluded. The information obtained will be used in a<br />
furthcr-rcaching project to dratt the thcorctical and<br />
dynamic principlcs rcquircd for safe motorcyclc braking<br />
on curves,<br />
In ordcr to improve the requirements for direct and<br />
indircct visibility from passcnger cars, a study has been<br />
conducted into the minimum light transmission capacity<br />
of windows in vehicles. One important conclusion drrwn<br />
from this study is that windscreens in futurc should be<br />
testcd aftcr installation and, oncc installcd, must satisfy<br />
the minimum requirements as regards light transmission<br />
capacity.<br />
A study has been initiated to further concretise the<br />
requirements for bus passenger protection. This study is<br />
intended to develop criterir which the senls in modern<br />
coachcs havc to satisfy in thcir role as rcstruint systcms.<br />
l3
13th lnternetlonel Technlcal Gonference on Experlmentel Sefety Vehlcles<br />
The experiments into the passive safety of road<br />
equipmcnt have been continued and extended at lhe<br />
Fcdcral Highway Research Institute's crash test facility.<br />
These experiments have included the testing and<br />
approval of marker posts on the basis of the conditions<br />
sct out in the "Technical Terms of Delivery" as well as<br />
the testing of guiding and slide barriers when impacted<br />
by passenger cars at spccds of 80 km/h.<br />
The interplay of members of the public, communication<br />
systems, organised rescue services and hospitals and<br />
clinics is often crucial in determining the success or<br />
failure of efforts to rescue accident victims. Studies have<br />
shown that laymen can often save lives and provide the<br />
preconditions esscntial for effective action by the<br />
professional rescue services. Rapid reporting of the<br />
accident is crucial in this regard. Nevertheless, it still<br />
takes an average of 5 - 8 minutes until an accident is<br />
reported and a further 8 minutes or so until a rescue<br />
vehiclc arrives at the scene of the accident - the average<br />
rescuc timc for road traffic accidcnts is thcreforc around<br />
l5 minutes. Accident victims are now being treated more<br />
and more frequently by an emergency doctor at the scene<br />
of the accident before being taken to a suitablc clinic for<br />
further treatment. This means that even persons with<br />
serious injuries which would otherwise prove fatal now<br />
still havc a chance of survival. This rcscuc chain can be<br />
further improvcd by greater involvcmcnt on thc part of<br />
laymen. Our studies revealed that no assistance was<br />
provided by members of the public at eyery third<br />
accident, cvcn though this was both necessary and<br />
possible. Thc rescue service can also bc madc morc<br />
efficient through specific efforts to improve communication,<br />
personnel training and coordination with clinics<br />
and hospitals. Scientific bases must be provided for<br />
further development work of this type.<br />
The German motor insurance companies began a new<br />
phase of their accident research work in 1990. All<br />
German insurance companies notified the HUK Association<br />
of accidents involving personal injury within the<br />
framework of third party motor ittsurance. Consequently,<br />
data from a total of well over 100,000 accidents are now<br />
available for special analyscs in thc fulure. These figures<br />
cover one in every four accident fatalities recordcd in<br />
1990. The following fields of study are planncd in order<br />
of priority: front, lateral and tail-end collisions in tcrms<br />
of frequency and serious injury, field studies into the<br />
effect of new technical systems (e.g. airbag) and<br />
measures designed for the protection of drivers and the<br />
other parties involved.<br />
The usually accepted international criteria are<br />
employed for the evaluatiort work. A Simplified Injury<br />
Scale has been devised by a group of mcdical advisers<br />
on the basis of the Abbreviatcd Injury Scale revised in<br />
1990 (AIS 90). This scale combines the advantages<br />
offered by an exact description of injuries based on AIS<br />
90 with simplified application for largc-population<br />
studies.<br />
14<br />
\<br />
One area of particular interest in the HUK accident<br />
evaluations currently taking place is that of young<br />
drivcrs and the problem of their higher-than-avcrage<br />
involvement in accidents. 40Vo of accidcnts involving<br />
serious/fatal injury are caused by drivers up to thc agc of<br />
25. Young mcn have a particularly high risk rate.<br />
Polls conducted as part of the "Young Drivers<br />
Campaign" clearly demonstrated that a very distinct<br />
differentiation must be made with new drivcrs as regards<br />
risk types and life-style. A direct corrclation with<br />
accident frequency does not appear feasible, however.<br />
The German motor insurancc companics are promoting<br />
safety programmes. In conjunction with the German<br />
Road Safety Council (DVR) a model has been devcloped<br />
for voluntary furthcr lraining of ncw drivers which has<br />
been given the name "Young Drivers Drivc Satcly".<br />
Some 2,000 new drivers will take part in a model<br />
experiment in 1991. The Federal Highway Rcscarch<br />
Institute will conduct the evaluation study.<br />
Following several years' analysis work, a representative<br />
database has been compiled from 2,000 accidcnts<br />
involving "trucks 3.5 t and abovc". Thc database<br />
includcs collisions with other vehicles as well as with<br />
pedestrians and two-wheelers.<br />
Fitting underridc protection to the front of trucks can<br />
bc cxpccted to yield a substantial reduction of around l0<br />
to 20Vo in the number of serious injuries suffered in all<br />
passenger car and truck collisions. Preliminary work conducted<br />
within the fralnework of the "Economic<br />
Commission<br />
for Europe" (ECE) has already commenced on a<br />
ncw ECE regulatiort. The requirements which underride<br />
protection mu$t meet will be tested in a research project<br />
conducted by the German motor insurance companics.<br />
An area of primary concern for the motor insurance<br />
companies is the protection afforded to child passcnBcrs.<br />
Material has been gathered on 1,200 child accident<br />
victims. Comparative studics rcvcalcd that unprotected<br />
children arc seven times more likcly to suffer serious/<br />
fatal injury than protected children. The agc group up to<br />
around 2 ycars was found to bcar a particularly high<br />
level of risk. The biomechanical criteria of small<br />
children require still more intensive research.<br />
A HUK project conducted in conjunction with the<br />
ADAC (German Automobile Cluh) performed a comparison<br />
bctween the behaviour of child protection systems in<br />
real accidents and crash tests. The tests revealed that<br />
rcarward facing systems for small children carry the<br />
Iowest loads. The tests also revealed, however, that using<br />
only adult belts to secure childrcn's seats often results in<br />
a very pronounccd rclativc moyement between the<br />
child's seat and the vehicle, a lact which involves an<br />
additional risk of injury. Both the protection affordcd to<br />
children by restraint systems and the actual filting of the<br />
system in the vehicle must be optimised.<br />
An extensive poll of 2,000 parcnts on "Problems<br />
with<br />
child protection systems" revealed that thc children are<br />
often heavier or lighter than the stipulated ECE weight
groups. This was particularly hue of Group I. Almost<br />
50Vo ot the parents questioned stated that their children<br />
did not like u"^ing child protection systems. This also<br />
explains why 84Vo of the persons questioned wanted to<br />
see improvcments made to the current systems"<br />
The majority of parents would like to see higher<br />
quality seat material, easier installation and relnoval,<br />
improved instructions for use which are perntanently<br />
affixed to the protection system, and locks which<br />
children themselves are unable to open.<br />
The use of child seats in the front passenger seat is<br />
being examined in accidcnt surveys conducted by the<br />
German motor insurance companies. The fact that such<br />
systems are easier to use is countcrcd by disadvantages<br />
relating to possible intrusions in the event of frontal<br />
collisions and problcms where vehicles are fitted with<br />
front seat passenger airbags. Closc cooperation with the<br />
manufacturers is required in this area to find suitable<br />
solutions.<br />
The Cerman automobile industry has continued its<br />
efforts to improve vehicle safety. Its annual report "Auto<br />
89/90" once again gives top priority to the protcction of<br />
occupants of passenger cars. Most passenger cars today<br />
have adjustable upper belt anchorages for the front scats.<br />
A number of vchicles are already fitted with belt systems<br />
which are anchored in the seat itself. Air cushion<br />
systcms integrated into the steering wheel are gaining in<br />
popularity and similar systems for the front scat<br />
passenger are anticipated.<br />
In the field of traffic jurisdiction, there are repeated<br />
calls lor accidcnt data recorders to be fitted in all<br />
vehicles. Given thc currcnt state of technology, units are<br />
available which store the travel spced and othcr data<br />
rclating, for cxample, to brakes or turn indicators, for a<br />
period of around 60 seconds. The Federal Government<br />
and the automobile industry believe that the problems<br />
involved in introducing units of this type are less<br />
technical in nilture than legal and organizational.<br />
Endeavours by the automobile industry to improve<br />
vehicle safety naturally also apply tor commercial<br />
vehicles. Efforts are therefore being supported to rcvise<br />
the provisions governing dimensions and weights of<br />
Japan<br />
Noritoshi Horigome<br />
Ministry of Transport<br />
First, a summary of thc cuffcnt state of traffic<br />
accidents in Japan is given. The number of automobiles<br />
owned in Japan totaled approximately 60 million units as<br />
of March 1991, meaning that there is one automobile for<br />
every two Japanesc pcople. The automohile is, therefore,<br />
an indispensable commodity without which the livelihood,<br />
economic and social activities of the Japanese<br />
people could not he maintained.<br />
Sectlon 2: Governmenf Sfatus Repons<br />
vehicle combinations in order to ensure that the length of<br />
the driver's cab meets all ergonolnic and safety<br />
requirements. Scat belts and anchorages are cnvisaged<br />
for all seats in the truck. Consultatiorts on design<br />
requirements and testing of speed limitcrs for trucks are<br />
in the final stages.<br />
A new generation of brake systems, known as "electronic<br />
brake systcms," is currently being developed for<br />
heavy commcrcial vehicles. Whereas existing brake<br />
systems control the braking prcssurc pneumatically, these<br />
new systems control it by electrical or elcctronic signals.<br />
Although these ncw systctns will not be available on the<br />
market until a few years' time, experts in thc automobile<br />
industry and govcrnmcntal agencies are already busy<br />
dcfining tcchnical requirements such as the clcctronic<br />
signal transmission structure.<br />
Since the start of the ycar, the automobile industry has<br />
been offering all new drivers free safcty training when<br />
they buy a new vehicle.<br />
An "Automobile Advertising Monitoring Group" has<br />
been in existence since 1988. By continuously assessing<br />
automobile advertising, it has made a valuahle<br />
contribution to rcducing possible areas of cont'lict<br />
between product advertising and road safcty.<br />
The Fcdcral Republic's status reports for previous<br />
conferences havc also outlined the extensive measures<br />
the Govcrnment has adopted to reduce environmcntal<br />
loading by rnotor vehicles. I will not enlcr into a<br />
discussion of these activities at this point, particularly<br />
since the current conference is interested primarily in<br />
safely aspects and most other participating countries are<br />
restricting themselvcs to such.<br />
Since the last conference was held in Swedcn in 1989,<br />
numerous rcscarch projects into vehicle safety have been<br />
concluded and nunrerous other thcnros hitvc bccn taken<br />
up. The results which have been achieved will be<br />
presented flt this confcrence and we will be following<br />
and discussing them with intcrest and attention. The<br />
generous exchange of expcrience and continued<br />
cooperation in research and dcvclopment work will<br />
remain of inestinrable value in thc future.<br />
With the progress of this motorization, the number of<br />
traffic deaths, totaled ll,ZZl in 1990, it I.3Vo increase<br />
over 1989 and traffic fatalities have remaincd abovc the<br />
10,000 line for three years in it row, from l9tttl to 1990.<br />
A remarkable feature of recent accidents is an increase<br />
in the dcaths of vehicle occupants, and lhcse fatalities<br />
accounted [or 40Vo of thc total traffic accident death toll<br />
in 1990. Also, the numbcr of fatal accidents at night-time<br />
driving accounted for 57Vo of the total fatal accidents.<br />
The most probable causes of thesc factors are a sharp<br />
rise in the numbur of agcd drivers, a drop itt the seat belt<br />
l5
ISth lnternethmtl Technlcel <strong>Conf</strong>erence on Experlmental Satety Vehlcles<br />
use rate (to some 70% from a high of 95Vo reached<br />
shortly after the enforcement of the Compulsory Seat<br />
Belt Usage Law in 1986), and a shift of people's<br />
lifestyles to a night-oriented pattern.<br />
Next is a brief explanation of the fundamental Traffic<br />
Safety hogram of the Japanese government. To cope<br />
with the increasc in traffic accidents, in March 1991 the<br />
Japanese Bovernment drcw up the 5th fundamental<br />
Traffic Safety Program providing traffic safety policies<br />
for the coming five years. The Program is aimed at a<br />
reduction of traffic fatalitics to below 10,000 per year by<br />
1995 through an active promotion of traffic safety<br />
measures.<br />
The main safety measures outlined under the Program<br />
are: the improvement of traffic safety facilities, the<br />
promotion of traffic safety education, the enforcement of<br />
effective traffic safety guidance and control, the<br />
upgrading of rescue operating systems and first-aid<br />
systemi and the expansion of research and development<br />
in thc ficld of traffic safety. Also, two other high-priority<br />
measures are comprehensive invcstigative studies on<br />
traffic accidents nnd securing the safety of motor<br />
vehicles.<br />
With regard to the promotion of safety measure$<br />
related to automobile in the future, the following five<br />
subjects will be explained. These subjects are:<br />
(l) A promotion of comprehensive investigative studics<br />
on traffic accidents<br />
(2) A expansion and strengthening of the Automobile<br />
Safety Standards<br />
(3) A promotion of technological development<br />
(4) A promotion sf research<br />
(5) An international harmonization of automobile standards.<br />
Beginning with Subject l, in order to take truly<br />
effective measures to prevent traffic-accidents, it is<br />
indispensable to grasp what actually happens in traffic<br />
accidents accurately, and to undertake investigativc study<br />
and analysis of the causes of accidcnts from the rcspcctive<br />
stand points of the driyer, motor vehicles and road<br />
construction.<br />
However, the comprehensive studies and analyscs of<br />
traffic accidents in Japan have not becn fully sufficient<br />
so far. Therefore, the government plans to establish a<br />
comprchcnsive traffic itccident research and data analysis<br />
institute in the near future through a collaboration of the<br />
government and private sectors. The major activities of<br />
this irrstitute will be:<br />
(l) To construct a data base integrating the various data<br />
on traffic accidents, a nd perform statistical (macro)<br />
analyscs of traffic accidents, using these data.<br />
(2) To perform individual case (micro) analyscs of<br />
accidcnts occurring in certain local areas.<br />
With regard to subject 2, the expansion and strengthening<br />
of the Safety Regulations will be explained. In<br />
August 1990, the Safety Regulations were revised to<br />
make it mandatory to install antilock brake systems<br />
(ABS) on large tractors, large trailers carrying dangerous<br />
goods, and large buses running on highways.<br />
Also, large trucks will be required install large-sized<br />
reflecting plates on the rear in order to increase the<br />
visibility of the vehicle and thus prevent large truck<br />
rear-end collisions. Further, large trucks will be requircd<br />
install improved rear underrun protective devices, to<br />
reduce thc damage incurred in large truck rear*cnd<br />
collisions. These measure are scheduled to take effect in<br />
Junc 1992.<br />
The Japanese government in October 1990 requested<br />
the Council for Transport Tcchnology to undertake a<br />
study on future Technical Standards to ensure vehicle<br />
safety, and the Council is now discussing this matter and<br />
expected to make recommcndations by the end of March<br />
1992.<br />
Recently, the five types of fatalities listed below have<br />
increased.<br />
(l) Accidents involving motor vehicle occupants<br />
(2) Accidents during night-time driving<br />
(3) Accidents on highways driving<br />
(4) Rcar-end collisions with trucks<br />
(5) Accidents involving young or aged drivers.<br />
Therefore, the Council for Transport Tcchnology is<br />
discussing safety measurcs to copc with these kinds of<br />
accidents.<br />
In addition to these countermeasures, the Council lbr<br />
Transport Technology is also discussing safety measures<br />
in relation to the increasing use of electronics in<br />
automobiles.<br />
Subject 3 pertains to the promotion of technological<br />
dcvclopments. In flddition to the expansion and strengthening<br />
of sal'ety standards, it is also cssential to promote<br />
technological development in order to improve the safety<br />
of automobiles.<br />
The government has been engaged in a five-year study<br />
sincc fiscal year l99l in the hope of developing by carly<br />
in the next century, practical Advanccd Safety Vehicles<br />
(ASV), as we call it, which are automobiles made more<br />
intelligent by exploiting the latcst clcctronic control<br />
technologies.<br />
The specific technologies examined in this study are<br />
how to perform automatic braking and aufomatic stccring<br />
by means of onboard sensors for detccting traffic and<br />
road surface conditions in the vicinity of the vehicle, a<br />
transmission processing and equipment and so forth so<br />
that the vehiclc itsclf can perform the rnost optimum<br />
safety opcrations; all airned at avoiding accidcnts, and<br />
minimizing injuries due to collisions.<br />
The fourth subjcct is that of Japan's promotion of<br />
automobile safcty research. Currently the following<br />
sludics are underway by the govcrnmcnl. and the private<br />
sector:
(1) The lighting of the braking lamp when the retarder<br />
equipped on large-sized trucks and buscs is in<br />
operation.<br />
(2) Improvements of safety in frontal collisions for<br />
passen8cr cars.<br />
(3) The protection of occupants in lateral collisions for<br />
passcnScr cafs.<br />
(a) The improvement of the conspicuousness of lighting<br />
and signalling deviccs.<br />
(5) Rcsearch into accident-avoiding systems for<br />
automobiles.<br />
(6) Rescarch and development of specialized taxi-use<br />
vehicles.<br />
Some of these studies will be presented by Japanese<br />
automobile manulactures at this conference, and it is<br />
hoped that the paflicipants in the conference will activcly<br />
exchange opinions on these fields-<br />
The fifth subject mattcr is the international harmonization<br />
of automobile standards. Since automobiles are an<br />
intcrnational commodity distributed worldwide, it is<br />
necessary to harmonize the automobile standards in each<br />
Italy<br />
Franco Zacchilli<br />
Ministero dei Trasporti<br />
Status reporl not availablc.<br />
Canada<br />
S. Christopher Wilson<br />
Transport Canada<br />
<strong>Int</strong>roduction<br />
It is once again my great pleasure to present the<br />
Canadian status rcport on progress in the area of automotive<br />
safety. Before starting, however. I would like to<br />
take this opportunity to thank the French government, the<br />
United States government, and the French Autonrobile<br />
Manufacturers for making this conference possible.<br />
Canadian Accident Environment<br />
I am plcased to report that we have seen the<br />
continuation of the downward trend in the annual fatality<br />
rate noted in thc last two Canadian progress reports. In<br />
1990. a total of 3.961 traffic fatalities occurred on<br />
Canadian roads and streets. This translates into a fatality<br />
ratc of 2.3 per 10,000 registered motor vehicles, the<br />
lowest rate cvcr recorded in Canada and represents over<br />
a 60 percent decline in the fatality rate since the early<br />
seventics. The 1990 fatalily total also represents the first<br />
Sectlon 2: Government Status Reports<br />
country as much ,* porribh, taking into consideration<br />
the respective traffic conditions of each country.<br />
Accordingly, Japan, along with the other major<br />
automobile producing countrics, has bccn participating<br />
actively in the United Nations ECEAVPZ9, which is<br />
playing a central role in international harmonization<br />
activities of automobile standards. Also, in 1987 Japan<br />
established JASIc, the Japan Automobile standards<br />
<strong>Int</strong>crnationalization Center, to support the harmonization<br />
activities of the Japanese government. Japan expects that<br />
the activities for the international harmonization at the<br />
stage of the ECEAVP29 is promoted further.<br />
Finally, as you are all aware, it is widely recognized<br />
that we today face not only safety problems, but also<br />
global environment issues. In particular, the issues of<br />
reducing COZ emissions and improving the safety of<br />
automobiles may be contradictory, as safety devices will<br />
tend to increase the weight of the automobile. Therefore,<br />
how to harmonize these contradictory requirenrcnts is an<br />
important topic which will be imposed on us in the<br />
future.<br />
time sincc 1962 that the fatfllity count in Canada dropped<br />
bclow 4000.<br />
We believe the increflsed use of seat belts has played<br />
an important part in this downward fatality, This is<br />
reflected in the vehicle occupant ffltality total which,in<br />
1990, is tcn perccnt lowcr than that in 1989. Thc national<br />
seat belt use rate of drivers has been monitored closely<br />
in direct observational surveys conducted annually by<br />
Transport Canada. Through the latter half of the nincteen<br />
seventies and the early eighties, the time period over<br />
which most of thc dramatic decrcasc in traffic ffltalities<br />
occurred, the seat belt use rate among drivers increased<br />
from under l5 percent to over -50 percent. Suhstantial<br />
furthcr progrcss in increasing thc seat bclt ratc hfls bccn<br />
made in recent years. The most recent survey, conductcd<br />
in June of 1991. showed a national scat belt usc rate<br />
among drivers of just over 85 percent, the highest rate<br />
rccorded to date. In 1990, Ministers representing all<br />
provinces, the territories and the federal government<br />
endorscd thc National Occupant Restraint Programmc,<br />
which seeks to attain a 95 pcrccnt usc ratc of seat bclts<br />
by 1995. This goal, vcry clearly, is now within reach.
13th lnternatlonal Technlcal Conterence on Experlmental Setety vehlcles<br />
Undoubtedly, another conffibuting factor has been the<br />
reduction in alcohol relatcd fatalities. In thc past dccadc,<br />
there has been a 28 percent reduction in the proportion<br />
of fatally-injured drivers-who were impaired.<br />
Regulatory Developments<br />
Regulatory priorities in Canada are sensitive to the<br />
global nature of the automotive industry and the importance<br />
of improved international trade unencumbered by<br />
artificial barriers. We hope that our rcgulatory initiatives<br />
rctain the high level of compatibility with foreign<br />
standards that historically existed while, at the samc<br />
time, respond to the needs and priorities of Canadians.<br />
In this context, the past two years have seen a number<br />
of changes to Canada Motor Vehicle Safety Standards.<br />
For the most part, these changes were very similar to<br />
those inFoduced in the United States. Two changes<br />
uniquc to Canada were also introduced. The first of these<br />
was the introduction of requirements addressing occupant<br />
rcstraint systems designed for use by the disabled. Thc<br />
sccond involves an alternative set of injury criteria<br />
addressing t'rontal crash protection requirements. These<br />
ncw criteria are based on the re$pon$es measured with<br />
Hybrid III crash test dummy in a 48 km/h frontal banier<br />
crash test. These new requircmcnts will be outlined in a<br />
separate technical prcscntation at this conference.<br />
Crashworthiness Research<br />
In the vchiclc crashworthiness area, our more recent<br />
rescarch cfforts addressing frontal crash protection have<br />
focussed on gaining a bcttcr understanding of the<br />
rcsponse of the human chest when loaded by a seat bclt<br />
and how accurately these responscs arc replicated by<br />
contemporary frontal crash test dummics such as the<br />
Hybrid III. Wc recently participated in a cooperative<br />
research programmc with both INRETS in France and<br />
the U.S. National Highway Traffic Safcly Administration<br />
to gather comparative chest deflection data using human<br />
cadavers and the Hydrid lll dummy. The cadaver testing<br />
portion of this programme was completed in France. The<br />
test apparatus used in this programme has now been<br />
returned to Canada whcrc it will be used to gain<br />
additional thoracic response data, this time with live<br />
human volunteers. In addition, as part of a scparatc<br />
cooperative programme with NHTSA, we have just<br />
recently completed a large number of frontal barrier<br />
crash tests using a Hybrid III fitted with a special<br />
inslrumentation package which allows the general<br />
dcformation pattern of the chest to be monitored.<br />
The proportion of new passenger cars fitted with<br />
"supplementary"<br />
air bag systems has increased greatly in<br />
Canada in recent years. This trcnd is cxpected to<br />
continue. The field effectiveness of such combination<br />
system$ and the accompanying u$agc ratc of seat belt$ in<br />
these vehicles is being monitored closely by the<br />
Department. We recently initiated a combined field<br />
accident data analysis and crash testing research<br />
18<br />
programme which seeks to quantify the effectiveness of<br />
air bag systems, whcn uscd in combination with munual<br />
three-point seat belts. As part of this programme two<br />
offset head-on vehicle-to-vehicle collisions were<br />
completed in which air bag fitted passenger vehicles<br />
were impacted by much stiffer and heavier pickup trucks.<br />
The findings will be discussed in the separate technical<br />
presentation which I made reference to earlier.<br />
In recent years much of our research effort has been<br />
directed to the issue of side impact protection with<br />
particulu attention being given to the best means by<br />
which such protection can be defined and regulated. We<br />
have bcen following, with great interest, the various<br />
regulatory proposals and initiativcs taken both in Europe<br />
and in the U.S. To assist thc Dcpartmcnt in its own<br />
deliberations over what course of action Canada should<br />
take, a combined field accidcnL analysis and vehicle<br />
crash tcsting programme was initiated in 1988. The crash<br />
testing portion of this programme examined, in the<br />
context of the Canadian situation, thc relativc mcrits of<br />
the various testing procedures and test deviccs cilher<br />
under consideration or adopted in thc U.S. and Europe to<br />
regulate side impact protection. To date, closc lo 30<br />
full-scalc vchicle crash tests have been completed ils part<br />
of this programme.<br />
From the lcsting completed to date, it is very clear<br />
that vehicle performance rankings based on the proposcd<br />
Europenn testing proccdurc can be expected to differ<br />
greatly from those obtained following the U.S. testing<br />
protocol. These diff'erences ciln be attributed prinrarily to<br />
differences in the design of the two moving barriers and<br />
their alignment rather than to differences in the dcsigns<br />
of the European and U.S. test dummies. Of the two<br />
barriers, the U.S. barrier and testing protocol produced<br />
damage patterns which showed much closcr agreemcnt<br />
with those observcd in staged vehicle-to-vehicle<br />
collisions conducted in our programmc. Thc final portion<br />
of our test programine will focus on the sensil.ivil"y of<br />
test rcsults to dummy design and other related<br />
considerations such as the position of thc dummy's arm.<br />
Crash Avoidance<br />
The past ycars have seen a number of regulatory<br />
initiatives addressing crash avoidance, particularly in the<br />
area of vehicle lighting. Two of thc morc significant of<br />
these pertained to increasing the conspicuity of vchicles.<br />
Thc first of thcsc was the requirement for a centre highmountcd<br />
stop lamp. Thc sccond and more recent is the<br />
requirement fcrr a daytime running light syslem. Fitment<br />
of thc lattcr bccame mandatory in Canada as of<br />
November 30, l9tt9, and in the context of North<br />
America, represents a uniquely Canadian requirement.<br />
Both of these requirement$i are currcntly thc subject of<br />
evaluntion studies. As yet sufficient field accident data<br />
have not been compiled to allow definitive statements<br />
regarding what impact either of thcsc standards have had<br />
on accident riltes. In thc casc of thc ccntrc high-mountcd
stop lamp requirement, the preliminary findings are<br />
cncouraging, although thcy show benefits which appear<br />
to be wcll short of those predicted in pilot studies. They<br />
suggest reductions in target accidents of between 7 and<br />
14 percent, depending on class of accident flnd the<br />
control group uscd as the basis of the effectiveness<br />
estimate. In the case o[ the daytime running light<br />
requirement our current efforts are directed largely at<br />
monitoring the use of driving lights in the daytime, on<br />
quantifying both the added vehicle production costs<br />
directly attributable to this regulation as well as the<br />
added costs due to increased fuel consumption and bulb<br />
replacement, and examining other related issues such as<br />
driver behaviour adaptation. The more formal field<br />
accident analysis portion of thc cvaluation programme<br />
will likely not be completed until 1994. However, I<br />
expect to be in a position to share some preliminary<br />
findings with you at the next <strong>ESV</strong> conference.<br />
Heavy vehicle safety continues to be of concern, with<br />
approximately l0 percent of traffic fatalities involving<br />
such vehicles. We are involved actively in joint research<br />
efforts, both with industry and NHTSA, on anti-lock<br />
braking requirements and on improved visibility of large<br />
vehicles. Research is also progressing on thc safety<br />
implications associated with in-vehiclc displays and other<br />
technological advances in road-vehicle-driver communication.<br />
The Netherlands<br />
Gerard Meekel<br />
Ministry of Transportation and Public Works<br />
<strong>Int</strong>roduction<br />
Holland: A unique country with its own special<br />
characteristics.<br />
It is a very "small" country, with:<br />
. l5 million inhabitants on33,724 sq. km. The density<br />
varies from 150 to more than 1100 inhabitants per<br />
square kilometer, with an average of 444 inhabitants<br />
pcr sq. km.;<br />
' a large number of vehicles-6 million;<br />
. a relatively high number of heavy goods vehicles-<br />
444,000;<br />
. an important function/part in the international<br />
transport of goods; and<br />
' a highly mobilc population.<br />
But it is a very "big" bicycle country-over 14<br />
million.<br />
Despite our relative prosperity and level of technical<br />
development, we suffer from enormous transport and<br />
traffic problems.<br />
A. Firstly, road traffic is increasing rapidly. Every day<br />
the accessibility of our cconomic centres is further<br />
endangered. If nothing is done about this problem,<br />
Sectlon 2: Governmer?t Slatus Beports<br />
School Bus Safety<br />
Finally, it is perhaps appropriate to direct my closing<br />
remarks to a class of vehiclc which, by virtually any<br />
standard, is the safest in operation in Canada. Most days,<br />
tens of thousands of children acrosrl Canada are<br />
transported daily to and from school in largc ycllow<br />
school buses. NotwithsLlnding their outstanding sitfcty<br />
record, the safety of thcse vehicles continues to be a<br />
topic of considerable interest, and sometirrtcs, cmotional<br />
debate. This is readily understandable given the precious<br />
nature of the cargo they transport. Recognizing the need<br />
to provide to interested parties morc comprehensive<br />
informalion on this special class of vehicle, the<br />
Dircctorate recently completed a backgrouncl paper<br />
which summarizes information availablc on school bus<br />
accidcnt studies, on safety standards, and on our<br />
demonstration programme of different bus seat and scat<br />
belt combinations, including rearward facing seats. This<br />
report has been distribulcd to provincial and territorial<br />
governments, school boards, safety organizations and<br />
interested membcrs of the public. We arc rcviewing and<br />
responding to the commcnts rcceived.<br />
I thilnk you lor your attention and look forward to<br />
listening to the upcoming technical presentations at this<br />
conferencc.<br />
we will soon be facing a total traffic-block. This<br />
poses a threat to both national and international<br />
transport. Withoul a change in policy, road tratfic<br />
will increase by 7UVo by the year 2010. The western<br />
part of our country would be simply a crazy-paving<br />
of cars. THE MOBILITY PROBLEM WOULD BE<br />
SOLVED!?<br />
Some indicativc figures: Road traffic increascd by<br />
LZVo in the period between 1986 and 1989; on the<br />
main roads this figure is even higher-2O7o. The<br />
economic and social damage as il consequencc ofthe<br />
traffic jam today has increased to the ilrllount of one<br />
billion guildcrs pcr year, and will rise to four billion<br />
in the year 2010 if policies are not chlnged.<br />
B. Secondly, tralfic and transport have negativc effects<br />
on thc environment. Not only is pollution ils a conscquence<br />
of gaseous emissions and noise ernission our<br />
concern, but the conscqucnces of the infrastructure<br />
on the natural environment must also bc reckoned<br />
with.<br />
c. Thirdly, fatalities and injuries on our roads appear to<br />
have stabilised tt an unacceptably high lcvcl. Each<br />
year is a disaster-over 1,400 people are killed and<br />
another 50,000 arc injured. But this happens<br />
gradually. If this were to occur in onc single<br />
accidcnt. the whole Dutch nation would be<br />
l9
ISth lnternatlonel Technlcal <strong>Conf</strong>erence on Experlmenta, Safety Vehicles<br />
devastated. It happened in 1953: the break in the<br />
sea-dykcs and the subsequent flood claimed 1,800<br />
lives. As a rcsult, during the course of the following<br />
35 years the'*Delta-Plan" project was carried out at<br />
a cost of 15 billion guildcrs.<br />
Somc indicative figures: After a period of<br />
declining accident rates, 1989 saw an increase of<br />
around IOVo in the number of road dcaths and<br />
injuries. This put the figures back up to their 1986<br />
level. In 1989 the total number of both fatalities and<br />
injuries among cyclists increased by 20Vo in relation<br />
to the 1988 figures. The cost of road-"hazards" is<br />
estimated at six hillion guilders per year.<br />
Automobilee<br />
Trucks .<br />
Buses .<br />
Motorcycle6<br />
Mopeds<br />
Cycles .<br />
Pedestrians<br />
Others<br />
, Road Gaeualty Figurer (1990)<br />
Deaths<br />
Total . ....1,376<br />
$erlously<br />
Inlured<br />
5,115<br />
407<br />
21<br />
749<br />
2,619<br />
3,277<br />
1,364<br />
28<br />
13,580<br />
Othsr<br />
Inluries<br />
Policy<br />
General<br />
At the end of 1988 the minister of transport in the<br />
Netherlands published her Transport Structure Plan, the<br />
SVV, outlining concrctc goals and the instruments which<br />
should be used to achieve them. The latcst update<br />
contains thorough analyses of the problcms tacing the<br />
transport sector over the next few ycars, both nationally<br />
and internationally-and of these, safcty is of major<br />
importance. Above all, it deals with all aspccts of<br />
Iomorrow's transport system. The goal: a sustainable<br />
society-defined as "socicty which meets the present<br />
generation's needs without jeopardizing future generations'<br />
ability to meet thcirs." The inrplication is that we<br />
must build a transport system which does not shift the<br />
burden of environmcntal problems onto future gcncrations.<br />
This will necessitate bold political choices.<br />
Two problem areas have been idcntified which should<br />
be dealt with in the near future in order to create<br />
tomorrow's traffic and transport system:<br />
1. Environment and amenities of life, and<br />
2. Accessibility.<br />
Today's gcneration must have the courage to take the<br />
necessary mea$urcs. We have a collective rcsponsibility:<br />
we must face it togcther.<br />
20<br />
702<br />
53<br />
2<br />
72<br />
gs<br />
s04<br />
144<br />
I<br />
13,401<br />
1,316<br />
1,316<br />
215<br />
9,463<br />
9.574<br />
4,653<br />
81<br />
38,380<br />
Road Safety<br />
This subject is dealt with in detail in the alreadyexisting<br />
Dutch MPV "Long Term Policy for Road<br />
Safety." It consists of an in-depth programmc within the<br />
aim of producing a Sustainable Traffic System. This<br />
MPV is aligned with the SVV as far as goal-setting is<br />
concerned. The road*safety goal-setting formulated in<br />
both SVV and MPV reads:<br />
. by 199-5, thc number of deaths shall be decreased by<br />
157o and thc number of injured by llVo, relative to<br />
1986;<br />
. by 2010 these figures should be 50Vo and, 40Vo<br />
respectively.<br />
The 1,529 dcaths and 50,081 injured wcre registered<br />
in 1986. It will be very difficult to attain the goats.<br />
However, if today's policy is enhanced, theoretically<br />
speaking it is still possiblc. The Dutch governmenl has<br />
therefore "sharpened" the present MPV-policy. The<br />
enhanced policy is based on two main items:<br />
l.<br />
--spearheads,"<br />
being:<br />
' drinking and driving,<br />
. safety aids,<br />
. speed,<br />
. dangerou$ locations,<br />
and two recently infioduced items:<br />
. hcavy traffic, and<br />
'cyclists.<br />
2. "the policy of encouragement," aimed at stimulating<br />
and supporting the efforts of local councils,<br />
Provinces, trade and industry, and road users<br />
thcmsclves. All piuties involved must be made aware<br />
of rhe full extent of the problem.<br />
In order to give you some idca of the Dutch approach<br />
to road-safety, I would like to present inf'ormation on the<br />
following:<br />
. thc cycli$ts' project,<br />
the Cycle Master Plan and<br />
. the heavy traffic projcct.<br />
Before going into detail, I would like to point out that<br />
there is a major differencc bctwcen the two projccts.<br />
Both deal with the issuc of road-safety. Howevcr, in the<br />
heavy traffic projcct lhc safety aspects of thc vehicle and<br />
those in relation to its surroundings are takcn into<br />
account, whcrcas in the Cycle Master Plan safety aspects<br />
as a consequence of encouraging the use of bicyclcs are<br />
dealt with as wcll.<br />
Cycle Master Plan<br />
Situation<br />
In view of today's problems, and tomorrow's<br />
Sustainable Traffic Plan, the use of the bicycle is to be<br />
encouraged, but without thc attcndant rise in traffic<br />
accidents.<br />
In order to he able to formulate an efficient long-term<br />
policy we need to analysc the bicycle as a mcans of<br />
transport.
The Pros<br />
The bicycle:<br />
. is very suitable for short distances;<br />
. is suitable for getting to and from public transport;<br />
' requires rclatively cheap infrastructural measures;<br />
' is non-polluting, silent, and has minimal impact on<br />
the environment;<br />
. requires little space when eithcr on the road or<br />
parked;<br />
. is now accepted as a means of transport in its own<br />
right-its image is improving;<br />
'is a reliable means of transport as far as time of<br />
arrival is concerned. You won't end up in a traffic<br />
jam;<br />
. is healthy and relaxing;<br />
. is a cheap means of transport, especially in the light<br />
of increasing prices of mtltor vehicles and public<br />
transpoil;<br />
. is an individual means of transport with positive<br />
aspects, e.g. door-to-door transport.<br />
The Cons<br />
. Cyclists run a relatively high risk of being involved<br />
in an accident.<br />
' The social safcly aspect of cycle routes is not always<br />
too good, especially when badly lit, overgrown with<br />
bushes, etc.<br />
. The quality of the cycle routes is frequently poor.<br />
. Lack of cycle-sheds, which leilds to a very high<br />
number of bicycles being stolen.<br />
' Lack of good provisions for combined use of bicycle<br />
and public transport;<br />
. Cyclists are subjected to weather conditionsalthough<br />
according to the Royal Ncthcrlands<br />
Meteorological Institute there is rainfall only 67o of<br />
the time.<br />
Strategy<br />
The Cycle Master Plan is designcd with both mobilitymanagement<br />
and safety-goals in mind, within thc framework<br />
of SVV. All aspects relevant to thc increased use<br />
of the bicycle and a good road safety system are taken<br />
into account. In order to create a bicycle-friendly<br />
environment the Minister of Transport has formulated<br />
several strategies, e.g.;<br />
. Physical planning policy should work towards<br />
concentration of living, working, shopping, and<br />
recreational amenities. in order to recluce the<br />
distances between these activitics.<br />
. Infrastructural policy should focus on safe and<br />
comfortable routes, especially for bicycles, including<br />
specific arrangements, e.g. parking boxes.<br />
'Through a programme of information and<br />
instruction, there shall be a general policy of<br />
encouragement towards a more frequent use of the<br />
bicycle, and wherever applicable, in combination<br />
with public transport.<br />
$ectlan 2: Governmenf Sfatus Reports<br />
The Cycle Master Plan will deal with all aspects<br />
which come undcr the jurisdiction of thc Minister of<br />
Transport by means of a project divided into themes, and<br />
goal settings formulated where applicable.<br />
Thc themes are:<br />
. infrastructure.<br />
. mobility,<br />
. safety,<br />
' anti-theft provisions anrl parking,<br />
. promotion, and<br />
. bicycle + public transport + companies.<br />
The aspects dealt with under the heading of "safety"<br />
are:<br />
l. classification of safety forcyclists and mopcd riders;<br />
2. advice for safe cycle infrastructures;<br />
3. further development of the conccpt of the selfcontained<br />
commercial-residential-recreational<br />
suburb;<br />
4. mopeds;<br />
5. education for cyclists in cycle traffic;<br />
6. a post-acadcmic course on "safe infrastructure for<br />
cyclists";<br />
7. symposium on *'safe and polite traffic, also for<br />
cyclists";<br />
L accidents involving cycles on public highways; and<br />
9. bicycle safety and crash-worthiness.<br />
Bicycle Safety and Crash-Worthiness<br />
Onc of the activities which can be employed to<br />
improve road sat'ety in general is thc stimulation of the<br />
use of bicyclcs. At prcscnt the cyclist runs a very high<br />
risk of injury, which means high numbers and relativcly<br />
seyerc injurics. So, simply stimulating use would mcrely<br />
increase the number of traffic casualtics. The governmcnt<br />
therefore first inaugurated a programmc to explore<br />
thc possibilities of increa.sing the safety of the cyclist.<br />
This prograrnmc is divided into three parts:<br />
. the cyclist,<br />
. the bicycle, and<br />
. the surroundings (infrastructure and other road<br />
users).<br />
Within each part the role of the three actors-the<br />
governmcnt, thc manufacturers, and the consumcrs/road<br />
users-mily be identified.<br />
The Cyclist<br />
Dutch mcdical data for 1990 and l99l has been<br />
examined. The objective was to gain more information<br />
concerning the extent and type of injuries amongst<br />
cyclists. Among the results of this study were two<br />
conclusi0ns:<br />
. The cyclist very often sustains injuries to the head as<br />
the result of the accident (approx. 507o of the<br />
accidcnts).<br />
' With respect to long-term effects of injuries, the<br />
cxtremities of the body need extra protcction.<br />
2l<br />
'!l<br />
{ ,j<br />
#<br />
'!3<br />
fl<br />
-i<br />
.i<br />
:n<br />
iti<br />
,* $<br />
t
13fi lnternetlonal Technlcal <strong>Conf</strong>erence on Experlmentel Setety Vehlcles<br />
Under discussion at the moment is how this protection<br />
can best be provided-by prescribing protective clothing<br />
and/or helmets, and/or by reconstruction of the<br />
surroundings.<br />
The Bicycle<br />
In l99l the government started a research programme<br />
to improve the safety and comfort of the bicycle. The<br />
first stage concerns the arrangcmcnt of those aspects of<br />
the bicycle which have an influcnce on its safety. The<br />
next stage will be to formulate and develop test<br />
procedures for all types of bicycles, specifying the<br />
minimum requircments for a safe bicycle. The last stage<br />
is a future-oricntated project-ignoring the current form<br />
of the bicycle, and with regard to such features as<br />
comfort, safcty and speed, what should be the form of<br />
the bicyclc o[ thc futurc?<br />
The Surroundittgs<br />
This part of the programme is divided into two main<br />
arcas: one concerning the infrastructure und the other<br />
concerning the other road users.<br />
Bccause the major interest of this conference is in the<br />
vchiclcs, we shall concentrate further on the nther road<br />
uscrs. The most frequent opponent of the bicycle is the<br />
private car, and onc of the most frequent types of<br />
accident is where thc front of the car strikes the side of<br />
the bicycle. Through analysis of mathcmatical<br />
simulations and accident reports, combined with the<br />
relevant medical data concerncd (stage l), we are trying<br />
to obtain input for new mathematical simulations of<br />
collisions between cyclists and private cars. Through this<br />
we are trying to gain greater knowledge of thc<br />
kinematics of the cyclist during the accident. The<br />
objcctivc is to learn which parts of the car play an<br />
important role in the injury-producing proccss during the<br />
accidcnt.<br />
Later we hope to get more information about the<br />
possibilitics of crcating a "soft nose" front for private<br />
cars. In this programme the results of thc EEVC projcct<br />
conccrning pedestrians are taken into account.<br />
For the third stagc of this project we are trying to<br />
stimulate the industry to participate in the progamme.<br />
The objectivc is to perform one (or if possible sevcral)<br />
full-scale collision experiments using adjusted models of<br />
existing cars. Using this approach we shall try to<br />
stimulate the car industry to produce cars with built-in<br />
safety-not only for the pflssengers, but also for the<br />
other road users.<br />
Anticipatcd rcsults should contain suggestions for:<br />
' optimized car front-cnds,<br />
. optimized bicycle forms * safe and comfortable, and<br />
. optimized crash-protection for cyclists.<br />
The government programmc concerning the improvement<br />
of the safety of cyclists is expectcd to be<br />
completed by Decembcr 1994.<br />
22<br />
Heavy Traffic<br />
Situation<br />
This projcct must also be regarded within the<br />
framework of SVV. Wc start with the reality o[ a certain<br />
need for transportation, and a related mobility. The<br />
existing national and intcrnational infrastructurcs affect<br />
not only the level of mobility, but also the means of<br />
transport, whether by road, rail, water or air. By virtue<br />
of their construclion, heavy trucks are both unsafe and<br />
aggressive. In view of this, choices must be made<br />
concerning the acceptability of heavy vehicles on the<br />
roads. They are, in fact, incompatihle with other road<br />
users.<br />
A favourable tendency towards combined-mode<br />
transportation an already bc sccn, but first of all the<br />
infrastructure and logistics need to be re-organiscd and<br />
developed into a more intcgrated system which makes<br />
more even and efficient use of the existing transportation<br />
nctworks. It must be borne in mind, howcver, that reorganising<br />
thcsc aspccts may lead to limiting conditions<br />
or consequenccs for road safcty. In the meantime we<br />
must improve heavy truck safety. However, wc rcalise<br />
that not much attention has been given to this calcgory<br />
in comparison with other categories. We arc somewhat<br />
behind as far as our knowledge of heavy truck safely is<br />
conccrncd.<br />
Strategy<br />
Since the safety aspects of heavy traffic have so far<br />
been under-cxposcd in rclation to other categories of<br />
road users we must first catch up. The Heavy Traffic<br />
Project has been divided into two phases. There are no<br />
goirl settings at this stage, due to lack of sufficient<br />
rclcvant information.<br />
Phase 1. Scheduled for completion in Novcmber 1992,<br />
this consists of firstly, improvcment of the present<br />
situation by:<br />
. incorporating safety-related aspects in projccts which<br />
alrcady exist as a consequence of SVV;<br />
' application of existing instrumenls and measures in<br />
order to improve road safety as far as heavy trucks<br />
ars concerned, espec ial ly through technically-related<br />
aspects.<br />
Secondly, with a view to a policy of encouragement:<br />
. f'ormulating a research and development programme<br />
in order to be able to formulate futurc measures;<br />
'creating support as a lirst stcp towards irnplemcntation<br />
of specific measures on a long-telrn basis;<br />
. developing future stratcgy; and<br />
. active international participation with the aim of<br />
dcveloping international lcgislation on aspects of<br />
road safety.<br />
Phase 2. Schcdulcd for completion in June 1993, this<br />
consists o[:<br />
' implementation of results from Phase 1;
evaluation and, where applicable, adaptation of the<br />
project;<br />
. research and development of new measures;<br />
. formulating the long-term policy.<br />
Research and development programmes will be<br />
formulated, based on the quantitative and qualitative<br />
analyses of the unsafe aspects of Heavy Traffic.<br />
Finally, a total evaluation of this project is scheduled,<br />
and the long-term policy will be cstflblished.<br />
Hedvy Truck Safety<br />
In view of the emphasis on truck safety a research and<br />
dcvelopment programme was commissioncd in 1991. The<br />
aim is to establish a good basis for R&D in this area.<br />
The programme deals with both passive and active safety<br />
of heavy goods vehicles and contains vehicle-,<br />
occupant-, and environment-related topics. With respect<br />
to passive safety, the research focusses on front-underrun<br />
protection in frontal collisions with private cars.<br />
Practical solutions arc studied in co-operation with<br />
manufacturers. An EEVC ad-hoc group is also studying<br />
this subject. With respect to active safety, the<br />
possibilities of several criteria and test-methods for the<br />
assessment of the stability and control of heavy vehicles<br />
Sweden<br />
Lennart Fremling<br />
Ministry of Transport<br />
<strong>Int</strong>roduction<br />
I take pleasure in reporting that since the 1989<br />
Expcrimcntal Safety <strong>Conf</strong>erence in Gothenburg, there<br />
has bccn progrcss towards improved safety of vehicle<br />
occupilnts, motorcyclists and other road users. We hope<br />
this trend will be lasting, although one importirnt<br />
explanation to the positive trend of reduced casualties<br />
last year can be influenced by a somewhat decreased<br />
travel indicated by the petrol consumption, that last year<br />
was 5 per cent lower than during 1989.<br />
The number of fatalities in road traffic accidents in<br />
1990 was 772 which is a decrease of 15 per cent compared<br />
to 1989 which had the highest figure since 1979.<br />
The fatality risk in Sweden is among the lowest in the<br />
world. The number of fatillities per a population of<br />
100,000 last year was 9.0 and per 100 million vehicle<br />
kilometres 1.25.<br />
A major goal in the Road Safety Office's effort to<br />
reduce the number of traffic fatalities and injuries has<br />
been to increase the use of occupant restraints. We hlve<br />
seat bclt use laws covcring both front and rear seirts of<br />
passcngcr cars. The use of safety belt use laws covcring<br />
both front and rear seats of passenger cars. The usc of<br />
safety belts has steadily increased from 80 per cent to 85<br />
per cent in front seat and from 10 pcr cent to 70 per cent<br />
Sectlon 2: Government Sfafus Reports<br />
are being evaluated. Another project focusses on the<br />
calculation of the dynarnic stability of articulated trucks.<br />
We foresee that this first step will be followed by further<br />
research on active and passive truck-safety topics over<br />
the coming years.<br />
Conclusion<br />
A lot of problcms, discussions, $evcral rcport$, other<br />
opinions, striking interests, incompatible priorities and<br />
financial aspects, etc., have resulted in SVV, and<br />
consequently many projects have already slarted or will<br />
shortly stafl.<br />
The Dutch Minister of Transport was challenged<br />
nationally. Additionally, as a result of the report '-Our<br />
Common Futurc," wc felt challcngcd by the world. So<br />
the policy was again argued and enhanced, and SVV-II<br />
was created. A great deal of work remains to be done in<br />
the neiu future. You need to challenge in order to be<br />
challenged. You need to be challenged in ortler to<br />
challcngc.<br />
So now we want to challcnge the world, and we are<br />
focussing on YOU AND YOUR KNOWLEDGE. Thank<br />
you for your kind attention.<br />
in rear seat over the last decade. Now, we have monitorcd<br />
a ccrtain dccrcasc o[ safety bclt usc. In thc mid<br />
80's wc launchcd scvcral information and promotional<br />
programs supporting the passage of law of ntandatory<br />
use in rear seat, I July 1986. The belt use improved. We<br />
now believe that the lack of programs designcd to build<br />
public support for belt use during the last years, whcn<br />
we were nearly satisfied with the use rate achieved, has<br />
contributed to the falling use rate. Therefore there is a<br />
need to restart activities to upgrade the existing belt use.<br />
Organized under the Ministry of Transport the<br />
National Road Safety Office is the central administrative<br />
authority for matters related to safety on the roads. The<br />
Swedish parliament set a tilrget in 1982 to reduce on a<br />
continuill basis the number of people killed and injured.<br />
It is obvious that we have not succeeded to attain this<br />
major goal. The numbers hitvc only bccn rcduccd lor<br />
children and motorcyclists during thc pcriod l9lt2 -<br />
1990.<br />
In December 1990 the government appointed an expert<br />
group to give proposals on how to organizc thc traflic<br />
safety sector in thc future, to morc effbctively reduce the<br />
consequencss oI vchicular trnnsportfltion. The investigation<br />
committcc lorwardcd thcir proposals in September<br />
this ycar. Thc proposal is aiming at reducing the number<br />
of organizations dcaling with road sat'ety and to Inilndate<br />
local administriltions to take over the responsibility for<br />
road safcty mcilsurcs in thcir own aroils.<br />
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t?h lnternetlonel Technlcal Conterence on Experlmentel Satety Vehlcles<br />
I)rivers Licensing<br />
Thc developmcnt of the driver haining schemes has<br />
continued. New schemes have been introduced for all<br />
types of driver training. Shortly, there will be new<br />
thcoretical tests for all categories of driving licenses, and<br />
already new tests for category A and B licenses have<br />
been introduced as we reported at the last conference. As<br />
a result we can see an improvement of thc drivcr training<br />
in driving schools,<br />
The training of driving school instructo$ is of very<br />
short duration, in fact the theoretical education is only<br />
20 weeks. To create opportunities for an improved driver<br />
training it is necessary to improve and cxtcnd the training<br />
of the instructors. We are considering an instructor<br />
education at university levcl. The length of the education<br />
is planned to be two years.<br />
New drivers are a high-risk group in traffic. One of<br />
thc main rcasons for the high risk is thc lack of experience.<br />
Therefore, we are considering learner driving from<br />
the age of 16. Wc have in this case been inspircd by a<br />
similar scheme already introduced in France. Training in<br />
a driving school will be compulsory before starting the<br />
learner driving- The extent of the compulsory part has<br />
not yet been decided.<br />
Elderly drivers are another high-risk group in traffic.<br />
A research and development programme has been initiated<br />
in order to evaluale this problem. We are especially<br />
interested in dementia and its consequences upon driving<br />
skills. Furthermore we have started a training programms<br />
on a theoretical basis for a group of elderly drivers. The<br />
aim is to find out whether a training programmc can<br />
contribute to an even larger risk reduction among elderly<br />
drivers.<br />
Finally we have continued our efforts to reduce<br />
drunken driving. The legal blood alcohol content limit<br />
was rcduccd to 0.0280 in 1990. This year we have introduced<br />
a special test for drivers sentenced for drunken<br />
driving with a blood alcohol content of at leasl 0.15c/o.<br />
When applying for a new driving permit a mcdical<br />
certificate about the fitness to drive has to be enclosed.<br />
This certificflte shall be based on a certain time of<br />
observation as well as laboratory tests. When a person is<br />
granted a driving pcrmit, a follow-up within a period of<br />
eighteen months is then compulsory.<br />
Research<br />
The need to improve the passive safety of cars in<br />
lateral collisions has been recognized during recent ycars<br />
both in the United States and in Europe. Side impacts<br />
account for more than 20Vo of all accidcnts and with a<br />
risk of scrious injuries of 35o/o, this is higher than for<br />
frontal collisions.<br />
The main injury causing parameters in side impacts<br />
are, firstly the door inner velocity at thc time of impact<br />
with the occupant and secondly the degree of car body<br />
latcral dcformation.<br />
24<br />
The occupant protection in side impacts can be<br />
improved by e.g. reinforcement of the car body and the<br />
door to reduce the door inncr velocity as well as the car<br />
body deformation, padding and airbag at the inside of the<br />
door to reduce chest, hcad/ncck and pelvis loading.<br />
The present status is that a joint Swedish study has<br />
been undertaken to find out the injury patterns and injury<br />
risks for different types of cars and for different impact<br />
directions, with the main results that head, chest and<br />
abdomen/pelvis are mainly exposed to lifc-threatening<br />
injuries while the neck and legs mainly receive injuries<br />
with risk of permanent disabilities.<br />
A simplified method has been developed and validated<br />
in fullscale tests. in order to be used in research and<br />
dcvclopment of side impact protective sy$tems. The test<br />
method comprises a reinforced door, mounted to a test<br />
sled and with a dummy sitting on a seat at right anglc to<br />
thc crash track. Thc door approaches the dummy at a<br />
constant speed and is then decelerated with a linear<br />
function applied. With this method different dummy<br />
paramctcrs havc bcen studied for a reference door and<br />
for two different door designs. Both designs have shown<br />
good improvements especially the one with polyethylene<br />
foam and an airbag. Thc choice of padding material has<br />
been evaluated by mathemrrtical simulations.<br />
The present status of these two projects will be<br />
rcportcd at this conference.<br />
In parallel with this mechanical test procedure a<br />
mathcmatical mcthod bascd on MADYMO has been<br />
developed. A two dimensional side irnpact. dummy has<br />
bccn developed, which now is validatetl against the side<br />
impact dummy (BIOSID). Most parts of the body are<br />
well correlated to the BIOSID. With rhis marhcmatical<br />
simulation method the mechanical tests are reploduced.<br />
Rear end impact injuries to the neck have been an<br />
increasing prohlem during the past decades in Sweden.<br />
Rear end car collisions cause the so called whiplash<br />
injurics. These injuries, often disabling, will be seen<br />
even in very low impact velocities.<br />
The injury mechanisms are not properly known today.<br />
We do not have adequate knowlcdge to develop an<br />
optimal seat with head-rest for minimizing the risk for<br />
whiplash injuries.<br />
Both basic and applicd research is going on to find out<br />
the injury mechanisms and the principlcs for an<br />
improved seatback/heirdrest design.<br />
Aftcr development of methods for applying both static<br />
and transient dynamic loads to the spine, rescarch has<br />
been undertaken to study biomechanical, biological and<br />
patho-anatomical effects of the spine under different<br />
loading conditions. Different biologicirl and<br />
morphological parameters have shown to influcncc the<br />
mechanical response of the spine, especially the bone<br />
mineral contcnt in thc vertebrae has shown to be a good<br />
predictor of ultimale slrength of spinal riegments.<br />
A method has been developed by Chalmers University<br />
to sludy the flow and pressure gradicnts in the spinal
canal during the whiplash movement. With this method,<br />
studics are now undertaken to investigatc the gradients,<br />
which could be the possible mechanisms to the probable<br />
nerve tissue effects.<br />
A method to study the nerve tissue function caused by<br />
differcnt loading conditions, especially transient has been<br />
developed and is now going to be used in the attempts to<br />
find the injury mcchanisms of whiplash injuries.<br />
Based on the current knowledge a rear impact dummy<br />
has been developed by Chalmers University to be used<br />
in the development of better headrests and seal.backs.<br />
The dummy is based on the Hybrid lll but with a<br />
completely new neck and spine and work is at the<br />
moment going on to validate the new dummy.<br />
Heavy Truck Safety<br />
The number of trucks on our roads is increasing.<br />
Truck-trailer combinations weigh 30 or 40 times as much<br />
as the cars and take far greater distances to stop, pass,<br />
turn and accelerate. Most big truck crashes involve<br />
passenger cars and when these crashes happen it is<br />
almost always the people in the cars who suffer most.<br />
The odds of surviving an impact with a heavy truck have<br />
been steadily diminishing. There is no doubt that we are<br />
in need of invcstigations exploring the feasibility of<br />
incorporating cost-effective design modifications to<br />
trucks.<br />
To demonshate the heavy truck braking problem, the<br />
Nordic countries in 1987 conducted a joint projcct irnd<br />
evaluated 400 heavy truck-trailer combinations for inservicc<br />
braking capabilities. Results from the braking<br />
tests revealed poor general braking performance duc to<br />
lack of maintcnancs and adjustmcnt and far-from-optimal<br />
brakc load distribution within the truck-trailer<br />
combination. For cxample over 50 pcrcent of the<br />
combinations were not able to meet acceptablc dcceleration<br />
criteria. This mcans that hazardous cargo is being<br />
transported under less-than-safe conditions in spite of<br />
fairly sophisticated annual hcavy fiuck lesting schemcs.<br />
Thesc results call for development of brake systclns<br />
that better match brake force distrihution to braking<br />
demand. We are in great need of a successful introduction<br />
of antilock systems and the Eurclpean Community<br />
has already taken the lead.<br />
After thc general ban on thc use of asbestos from<br />
1988, industry was faced with a big task to restorc the<br />
safe brake properties in the heavy vchicles. A part of thc<br />
hcavy lruck braking problem was An in-scrvicc probletn<br />
when replacing brake linings. The aftermarket supply of<br />
linings was unregulated and often incompatible<br />
lining/drum combinations were fnund. An international<br />
standard fbr replacement linings is needed. As an<br />
intermedialc measure we havc established a Swcdish<br />
Standard for rcplacement linings. Tlris standard is legally<br />
applied from January 1992. We arc now expecting a<br />
gradual improvement in this area.<br />
Sectlon 2: Governmenf Stetus Beports<br />
It is equally important that we also continue to<br />
improve the occupational safety in trucks.<br />
In Sweden dynamic testing of heavy truck cabs has<br />
been mandatory since 1961. The testing method.s have<br />
been slightly revised in 1979 and 1981. Thus the<br />
reinforced truck cabs have saved many lives through the<br />
years.<br />
Child Safetv in Cars<br />
Among children and young persons road accidents are<br />
the most frequent single cause of death. The safcty of<br />
childrcn has therefore been a matter of great concern in<br />
Sweden for many years.<br />
The problem of protecting children in cars arises<br />
immediately after the birth of thc child. We have<br />
therefore a nation wide system of lending parents<br />
suitable restraints for newborn babics lor a period of 9<br />
months. We bclieve this is an effective way of promoting<br />
the need for life-long protection in vchicles.<br />
We find it encouraging that the Swedish experience of<br />
rearward facing child restraint systcms, now in use for<br />
over 20 years, reduces the risk of injury by 90-95%.<br />
These seats are used for children up to an agc of 3 years<br />
and are usually mounted in the front seat passenger<br />
position leaning against the dashboard. This excellent<br />
protection is parallelled only by a similar experience in<br />
the U.S.<br />
Thus the widespread use of child restraints in Sweden<br />
especially the rearwurd facing designs, has proved to be<br />
very efficient and is now the best available proteclivc<br />
system.<br />
It seems only reasonable that we should have the<br />
possibility of casy access to propcrly fitted protective<br />
systems for both adults and children in the family car. A<br />
new initiative from the industry to respond to thc public<br />
demand and also to prevcnt misuse of child restraints is<br />
to integrate them into normal car seilts.<br />
Thcsc integrated child restraints, which are designed<br />
and availablc for several flgc Broups, can in fact<br />
introduce a Breater risk when used in the forward<br />
position for smaller children who arc normally at prcscnt<br />
using rcarward facing designs in Swcdcn. This<br />
devclopment ciln create a problem for small children and<br />
has therefore to bo monitored with great carc.<br />
Another problem is that il passcnBer airbag obviously<br />
can be dangcrous in combination with a rearwiud facing<br />
child restraint. Some dynamic tests have been performcd<br />
with different combinations of child seats and dashboard<br />
designs. These tests show that thc dummy accelerations<br />
will rcach very high levcls and thilt somc child seats<br />
cvcn can disintegrate. A paper will bc prcsented during<br />
this conference in Session 9 showing sontc of the results<br />
received and possible remedics lo the problem will be<br />
discussed.<br />
Head-on collisions occur most frequently at an angle<br />
of appnrximatcly l0-30 degrees to lhe longitutlinal axis
13th <strong>Int</strong>ernetlonel Technlcal <strong>Conf</strong>erence on Experlmentat Safety Vehlctes<br />
of the vehicle. However, child restraints are only tested<br />
in zero degree dircction. For forward facing designs a<br />
much higher lorward displacement of the dummy is<br />
recorded for oblique impacts than for the zero degree<br />
direction. This knowledge calls for a revision of the<br />
ECE-Regulation 44.<br />
The protection in side impacts is limited. In Session 3,<br />
a paper will be presented discussing the injury mechanism<br />
in side impacts, and a test method is proposed for<br />
use together with chitd restraints in ECE mass group I.<br />
Vehicle Lighting<br />
Signalling is a very important factor in primary safety.<br />
The prevcntion of rear-end accidents in particular is<br />
largely depcndcnt on the swift receipt and interpretation<br />
of information by the following driver. Such information<br />
is transmitted principally by rear signal lamps on the<br />
vehicle and the signalling functions of rear lights are<br />
becoming steadily more complex. Especially position is<br />
used to code or to draw attention to information. In the<br />
US high mounted stop lamps have shown to have an<br />
excellent effect. For this reason we wanted to introduce<br />
this safety feature by legislative means in 198lt.<br />
Unfortunately ongoing European harmonization in the<br />
vehicle $ector persuaded us to withdraw this proposal. In<br />
the meantime we havc welcomed the initiatives of<br />
manufacturers who arc introducing such safety features<br />
ahcad of any legal requirements.<br />
Thus a number of car models have been equipped with<br />
high mounted stop lamps during rccent years. A field<br />
study has shown that the high mountcd stop lamps arc at<br />
least 1070 effective in reducing rear end collisions in<br />
Sweden. Fully applied the annual benefits for the lamp<br />
from reduced property damagc are estimated at 60<br />
million SEK. The insurance companies jointly have now<br />
launched a campaign to persuade car owners to equip<br />
their cars with high mounted stop lamps.<br />
In order to increase conspicuity of heavy and long<br />
vehiclcs, Sweden is applying the ECE Regulation No. 70<br />
(rear marking plates) for trucks, tractors, trailers and<br />
semi-trailers with a weight cxceeding 3.5 tons.<br />
Sweden, in 1973, introduced a national requircmcnt<br />
for side marker lamps on trucks excccding 6 m and all<br />
trailers, to make these vehicles merri visible for the side.<br />
Now ECE has decided on a Regulation for side marker<br />
lamps, with requirements similar to ours. This draft<br />
regulation has gathcrcd wide support in Europe.<br />
Cars<br />
Pelrol<br />
Injured<br />
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Killed and Inlured In Road Tralfic Accldents,<br />
Gars in Use end Petrol Deliveries 1968-1990<br />
(lnder 1968 = 100)
United States<br />
George L. Parker<br />
Highway Traffic Safety Administration<br />
National Highway Traffic Safety<br />
Administration<br />
The first <strong>Int</strong>ernational Technicat <strong>Conf</strong>erence on<br />
Experimental Safety Vehicles (<strong>ESV</strong>s) was held in Paris,<br />
France, 20 years ago. Since the first <strong>Conf</strong>erence,<br />
dramatic changes in automotive safety have occurred<br />
worldwide due in pafl to the collaborative safety<br />
technology efforts brought about by these confcrences.<br />
Many of the experimental safety devices developed<br />
under the original program are standard equipment on<br />
motor vehicles built today. Through these and other<br />
conferences dealing with motor vehicle safety, we have<br />
been able to increase, on an international lcvel, the<br />
importance oI motor vehicle safety.<br />
The commitment to motor vehicle safety in the United<br />
States is as strong today as it was in l97l when<br />
NHTSA's Chief Scientist, Dr. Robert Brenner,<br />
announced to the audience the "best wishes of President<br />
Nixon for a succcssful meeting." Today, President<br />
George Bush is cqually concerned with transportation<br />
issues, and, in Februiuy 1990, he issued a National<br />
Transportation Policy (NTP). The President, through this<br />
national policy, has made a commitment to the American<br />
public to continue to "cut the death rate and reduce the<br />
traffic death toll below the current level through the next<br />
decade, even in the face of incrcasing lravel."<br />
This transportation policy has been fully supported by<br />
the U.S. Department of Transportation and has brought<br />
transportation issues to an even higher level of<br />
awareness nationwide. One of the major themes of the<br />
NTP is to "Ensurc thflt the Transportation Systcm<br />
Supports Public Safety and National Security." Naturally,<br />
this encompasses all modes of transportation, howcver,<br />
a major challenge rests with the National Highway<br />
Traffic Safety Administration (NHTSA) to reduce the<br />
more than 44.000 deaths and 4.8 million motor vehicle<br />
related injuries which occur annually on U.S. highways.<br />
The National Highway Traffic Safety Admini.stration<br />
has planned a vigorous Research and Developmcnt<br />
program to support the President's NTP goals and to<br />
meet the demands of future tran$portation safety.<br />
Currently, motor vehicle fatalitie$ account for more than<br />
90 percent of the transportation fatalities, and are the<br />
leading cause of injury in the United States. As part of<br />
an overall program, we have developed a 5 year R&D<br />
plan which addresses all aspccts of motor vehicle safety.<br />
The program plan deals with the problems of today, such<br />
as enhanced data collection activities and vehicle crash<br />
avoidance and crashworthiness issues. We have also<br />
examined the issues that may be of concern in the next<br />
century. NHTSA has begun actions to help ensure that<br />
Sectlon 2: Governmenl Status Beports<br />
the needs of the older driver population will be met, that<br />
advanced technology from <strong>Int</strong>elligent Vehicle/Highway<br />
Systcms (IVHS) programs will bc tully used to improve<br />
crash avoidance and will bc a benefit rather than a<br />
hindrance to drivers. Wc have also initiated programs<br />
with university centers to help ensure the science of<br />
motor vchicle safety continues into the next decade.<br />
In addition to its R&D plan, NHTSA has devekrped an<br />
Agency hiority Plan which describes aggressive<br />
programs to address traffic safety. Thcse programs and<br />
activities include reducing the lcngth of time to issuc<br />
rulemaking actions; developing progralns for State and<br />
community implementation which will increasc safety<br />
belt usagc to 70 percent by the end of 1992, incrcase<br />
proper child restrainl usage, and reducc thc number of<br />
drug and alcohol related crashcs. NHTSA is also<br />
strengthening its 1987 collaborative pilot project with the<br />
Centers for Disease Control in the areas of data<br />
collection linkages itnd biomcchanics. The Centers for<br />
Disease Control progrilm is still growing, having just<br />
held its Third Injury In America <strong>Conf</strong>erence which was<br />
co-sponsored by NHTSA. Thc theme fbr this year's<br />
<strong>Conf</strong>erence focused on a National Agenda for lnjury<br />
Control, which includes motor vchicle safety issues for<br />
the year 2000.<br />
Crash Environment<br />
Since l97l thc fatality rate has been dropping in the<br />
U.S. Fatalities per 100 million vehicle miles travclled<br />
were 4.5 in l97l and had declined to 2.I in 1990. Other<br />
fatality ratcs have also declined. The rate per 100,000<br />
population dropped from 25.40 to 17.90; and the fatality<br />
rate per I00,000 registered vehicles declined from 4-5.17<br />
to 23.08. This year, we estimatc lhat 44,000 people will<br />
die, another 5?3,000 will be hospitulized, and 4.8 million<br />
will be injured but not hospitalizcd as a direct result of<br />
motor vehicle crashes. Bascd on a May I99l Fedcral<br />
Highway Administration report, the average Iifetime cost<br />
pcr person injured by a motor vehicle in the U.S. is<br />
$21,000. The average cost per fatality in the U.S. is<br />
$652,500, for a scrious injury (AIS 3-5) thc cost is<br />
estimatcd at $106,600 and f'or a minor injury the cost is<br />
estimated at57.727. All of these estimatcd costs include<br />
property damage.<br />
Passenger car fatalities iue still the largest proportion<br />
of U.S. falalities-s4 percent for 1990 followed by light<br />
trucks and vans at 19.3 percent. Nonoccupant fatalities<br />
accounted tor 16.7 percent, and motorcyclists representcd<br />
7.3 percent of' thc fatalities. The number of dcaths in<br />
each of these categories was down compared to 1989.<br />
How much progress have we made in the United<br />
States ovcr thc last 20 years'l It is projcctcd that if we<br />
had remained at the l97l fatality rate level, 96,600<br />
people would havc dicd on the U.S. highways in 1990.<br />
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We have made tremendous progress over the last 20<br />
years, but we still have a long way to go.<br />
While we continue with our R&D efforts. our<br />
rulemaking activities and our statc and community<br />
programs directed towards reducing motor vehicle<br />
fatalities and injuries, we must also look toward the<br />
challenges the next ccntury may bring and be prepared<br />
to meet the requirements of intelligent vehicle/highway<br />
safety systems, and the needs of an oldcr driving<br />
population.<br />
Crash Data Collection and Analysis<br />
The Natiorral Highway Traffic Safety Administration's<br />
National Center for Statistics and Analysis develops and<br />
uses large $cale automated data bases to support problem<br />
identification, program planning, and program cvaluation.<br />
We have made several important changes to our<br />
data collection sources which we believe will be of<br />
benefit not only to our Agency, but also to the entire<br />
highway safety research community, nationally and<br />
internationally.<br />
Our crash data system is composed of several<br />
components serving varying needs. Our Fatal Accident<br />
Rcporting System (FARS) is a census of all fatal crashes<br />
occurring on public roads in the U.S. Our National<br />
Accident Sampling System (NASS) is a yearly collcction<br />
of data from a statistically representative sample of<br />
crashes occurring in the U.S. This system is composed of<br />
a Crashworthiness Data System and a General Estimates<br />
System. These two primary crash data systems, FARS<br />
and NASS, iue complemented by State crash data<br />
systems compilcd from police accidents reports for a<br />
number of States.<br />
NHTSA's Fatal Accident Report System (FARS) is a<br />
system which providcs basic information on all highway<br />
traffic crashes in the U.S. in which one or more people<br />
die of injuries within 30 days of the crash. This<br />
automated data base systcm has been in operation fbr the<br />
past l6 years and contains detailed information (over 100<br />
data elements on each fatal crash) on approximatcly<br />
800,000 fatalities. In t991, l5 additional data elements<br />
were added to the FARS collection to focus on crash<br />
avoidance mansuvers, heavy trucks and their cargo, and<br />
occupant ejection path. We are al$o continuing the I987<br />
initiative to link FARS data with information from death<br />
certificates and our collaboration with the Federal<br />
Highway Administration to expirnd its Trucks in Fatal<br />
Accidents (TIFA) file. The TIFA filc contains<br />
information extracted from the FARS files and FHWA's<br />
motor carrier accident files. FHWA's motor ciurier data<br />
files contain detailed information on regulated carriers<br />
such as the characteristics of medium/heavy trucks<br />
involved in fatal crashes, cargos carried, con[iguration of<br />
the trucks, and the characteristics of drivers opcrating<br />
them. These efforts provide us and the entire highway<br />
safety research community with valuable insight into the<br />
factors influencing injury scverity, the crash involvement<br />
28<br />
of heavy trucks, and other critical areas in fatal traffic<br />
crashes.<br />
Our National Accident Sampling System (NASS)<br />
provides information from investigations of a statistical<br />
sample of police reported crashes at all lcvels of injury<br />
severity. NASS is composed of two data files, the<br />
Crashworthiness Data System (CDS) which contains<br />
detailed information on approximately 7,000 crashes<br />
each year and the Gencral Estimatcs System (GES) in<br />
which crash information is extracted from a samplc of<br />
about 46,000 police accident reports annually. In 1990,<br />
a 6-month NHTSA-wide review of the Agency's crashworthiness<br />
data needs concluded that "representative<br />
national estimates" were essential to the Agency's<br />
research and regulatory programs and that the CDS<br />
sampling plan should be modified to increase the<br />
likelihood of selccting crashes that resulted in serious<br />
injury. Because it has been shown that il person who is<br />
actually hospitalized is more likely to have a serious<br />
(AIS 3+) injury than onc who is not hospitalized, the<br />
CDS sampling methodology will be modificd in 1992 to<br />
identify such crashcs. This rcvision is cxpcctcd to yield<br />
about 20 percent more serious injury cases. Work also is<br />
in progress to convert the CDS to the AIS 90 injury<br />
coding and to add other available and useful trauma data<br />
to the data files. The General Estimatcs System provides<br />
data necessary t'or the Agency to produce accurate<br />
estimates of the magnitude irnd general trends in<br />
highway safety. In 1989, the GES sampling phn was<br />
modified slightly to increase the annual sample of heavy<br />
truck crashes to about 7,000.<br />
NHTSA's Statc Data Systems Program provides a data<br />
base consisting of all police reported crashes. This data<br />
basc allows for a wide variety of highway safety issucs<br />
to bc assessed. Collectivcly, thc 50 Unitcd Stalcs spcnd<br />
over 500 million dollars each year collecting information<br />
abrlut the crashes that occur on the Nation's highways.<br />
Thcrc are ovcr l3 million policc rcportcd crashcs<br />
annually. A major effort to enhance the analytic utility<br />
of police reported accident data was initiated in 1990.<br />
Thc objective of this program is to crcatc national<br />
uniformity in the variables that are essential to the use of<br />
police reported accident data for highway safety<br />
analyses. This can be achicved by adding a limited<br />
numbcr of critical automatcd dala rcporting elcments<br />
(CADRE) to thosc thc Statcs alrcady collcct. A final list<br />
of CADRE items will bc puhlished in thc Fcdcral<br />
Register this fall, and we are working with the States to<br />
ensurc the adoption of these new data elernents in all<br />
Statcs. In addition, we have expandcd our use of State<br />
accident files as a source of data, and currently havc on<br />
hand data from 28 Statcs. Thcsc data covcr severitl years<br />
of crash expericncc and havc been a valuable source of<br />
information for crash avoidance, crashworthiness, and<br />
highway safety analyses.<br />
Another data collection activity that we have placed a<br />
high emphasis on is linking crash data files to hospital
ecords, trauma center records, and emergency services<br />
systcm records, better known as trauma files. We believe<br />
the trauma data are a potentially important source of<br />
information for quantifying the relationship between<br />
crash characteristics, motor vehicle design features, and<br />
the injury consequences of motor vehiclc crashes. At<br />
present, however, obstacles to linking these data with<br />
police accident reports remain and experience in utilizing<br />
these data to address many highway safety issues is<br />
limited. An initial invcstigation of these issues is being<br />
examined in a joint protect with the State of Virginia to<br />
study injury mechanisms in motorcycle crashes. This<br />
project will provide the experience needed to assess the<br />
extent lo which trauma data can support highway safety<br />
analytic requirements. This project will also assist in<br />
dcvcloping a model trauma data system and assessing the<br />
status of trauma data system$ nationally.<br />
Major analytic activities undertaken by thc Agency<br />
since the last <strong>ESV</strong> <strong>Conf</strong>erence include: an analysis of<br />
occupant head injury protection, relative injury/fatality<br />
risks for front and reitr seat child occupants, an investigation<br />
of door latch and hinge failure, an analysis ot the<br />
characteristics of heavy truck crashes, a study of the<br />
relationship between measurcs of static and dynamic<br />
vehiclc stability and light duty vehicle rollover<br />
propensity; and an investigation of the relationship<br />
between passenger car weight and fatality and injury<br />
likelihood. We are presently estimating that from 1983<br />
through 1990, almost 25,000 lives have been saved by<br />
the use of safety belts; from 1982 through 1990, over<br />
1,500 children's lives have becn saved by the use of<br />
child restraints; and from 1982 through 1990, over 4,700<br />
lives havc been saved from the use of motorcycle<br />
helmets. We estimate that livcs savcd from 2l year old<br />
minimum drinking age laws currently avcrage approximately<br />
1,000 per year, with over 11,000 lives saved<br />
since 1975.<br />
Motor Vehicle Safety Research<br />
Advisory Committee<br />
In May of 1987, the Motor Vehicle Safety Research<br />
Advisory Committee (MVSRAC) was established to<br />
foster increased communication with researchers working<br />
in industry and academia. The Cotrttnittee has servcd as<br />
a forum for the considcration and cotntnunication of<br />
current and planned research projects of both NHTSA<br />
and other organizations.<br />
The Committee has provided the Agency with<br />
information leading to a bettcr undcrstanding of motor<br />
vehicle safety research needs in the areas of rollover<br />
crash prevention and protection, biomechanics of injury,<br />
crash data analysis, hcavy truck safety, and the use of<br />
"Information<br />
Age" technologies to improve tnotor<br />
vehicle saflety. Subcornmittees have bccn cstablished to<br />
examine specific research topics in greater tcchnical<br />
detail.<br />
Sectlon 2: Government Sfafus Repofts<br />
Crash Avoidance Research<br />
Crash avoidance research continues to provide the<br />
basis for reducing the number of crashes and/or their<br />
severity through changes to the vehicle to improve the<br />
vehiclc's performance or the match between the driver<br />
and the vehicle.<br />
I nt e lli ge nt V e. hicle H i g hway Slrter4s<br />
A major new initiative in Crash Avoidance rescarch<br />
sincc the last <strong>ESV</strong> <strong>Conf</strong>erence is the <strong>Int</strong>clligent<br />
Vehicleftlighway Systems (IVHS) program. Recent<br />
developments in the fields of electronics, artificial<br />
intelligence, and communications provide the basis for<br />
designing and producing the smart sensors, compulers,<br />
and control systems needcd to facilitate and augment<br />
driver and vehicle performance. In-depth crash<br />
investigation studies in the United have consistcntly<br />
shown that human error is a major contributory factor in<br />
most crashes. Advanccd technology providcs the<br />
potential to help drivcrs better sense impending danger,<br />
sense and alcrt drivers of lapses in their judgement or<br />
skill, aid them in performing the driving task, and,<br />
ultimately, compensate for some of their errors.<br />
NHTSA's eftbrts in IVHS havc two major thrusts.<br />
First, NHTSA is embarking on an cxtcnsive program to<br />
define specific crash avoidance situatiotts and conditions,<br />
to develop performancc specifications for promising<br />
IVHS applications that could improvc thc crash<br />
avoidance capabilities of drivers and vchicles in these<br />
situations, and to evaluate the performance, reliability,<br />
and costs associated with devclopcd products and<br />
systems. Second, NHTSA is working with other DOT<br />
agencies and other participants to assess thc safety<br />
impact of other IVH systems which arc being developed<br />
primarily lor thcir mobility or congestion relicf bcnefits.<br />
The keystone ol'lhc NHTSA performance speci[ication<br />
research will be multidisciplinary progrilms for<br />
countcrmeasure$ that help prevent crashcs or help reduce<br />
the scvcrity of a crash. The programs will require the<br />
integration of a numbcr of facets. An initial step will bc<br />
a review of collision data files such as the National<br />
Accidcnt Sampling System (NASS), thc General<br />
Estimates System (GES), the Crash Avoidance Research<br />
Data file (CARDfilc) and individual State databascs as<br />
a means of defining problems in a quantitative way. This<br />
review will bc couplcd with preliminary cstimatcs of<br />
benefits that might accrue to the implcmcntation of<br />
various countermeasures. This study is already underway<br />
and is expected to bc complctcd by mid- 1992. Thc initial<br />
problem definition step will be followed by individual<br />
progrflms to develop pcrformance specifications for<br />
countermeasurcs for high priority problem areas. These<br />
individual programs will include development of specifications<br />
for the performance of the driver/vehicle<br />
interface as wcll as the perfortrtance of such hardware<br />
features as sensors, data proccssing equiprnent, and<br />
29<br />
,i
13th lnternatlonal Technlcal <strong>Conf</strong>erence on Experlmental Safety Vehlcles<br />
software and communication links. A key question that<br />
will be addressed in each program is "What is the best<br />
way to elicit a necessary collision avoidance action from<br />
a driver"? It is expected that initial work will focus on<br />
rear-end collisions. collisions associated with lanechangcs,<br />
collisions that involve leaving thc road, and<br />
intcrsection collisions. Thcsc programs will bc initiated<br />
this year and will be integrated with human factors<br />
projects that are already in place. Current human factors<br />
projects include an assessment of driver workload,<br />
studies of the human factors considerations for in-vehicle<br />
crash avoidance warning signals, and development of a<br />
capability for vehicle-based driver performance<br />
monitoring.<br />
In the second area, the current emphasis is on<br />
congestion relief sy$tems that provide route guidance and<br />
navigation information to driver$. An underlying<br />
hypothesis of these system$ is that drivers with such a<br />
system will be able to navigate better than drivcrs who<br />
do not. If this is true, drivers should have a more<br />
worry-free and safer driving cxpcricncc because they<br />
would be routed around congestion and delay-causing<br />
incidents, and should, therefore, spend less time being<br />
lost or confused about their location. The counter<br />
hypothesis is that drivers might need to dcvote so much<br />
time and attention to obtaining the ncccssary information<br />
that safcty could degrade. Thus, these systems may have<br />
a measurable impact on safety, either positive or<br />
negative, depending on their design and operation. These<br />
two sides of the safety question will bc addrcsscd as part<br />
of the system evaluation.<br />
NHTSA is currently working with other pilrtners<br />
(General Motors, the American Automobilc Association,<br />
the Federal Highway Administration, the State of<br />
Florida, and the City of Orlando) to evaluate the<br />
performance of the TravTek system. TravTek (short for<br />
Travel Technology) is an advanccd motorist information<br />
demonstration project which will provide navigation<br />
a$sistance, real-time traffic information, routc sclection,<br />
and other information to tourists and other travelers in<br />
Orlando, Florida, for a period of I year starting January<br />
l, 1992. A key element of the TravTck program is<br />
inclusion of a plan to evaluate trip/network efficiency,<br />
congestion avoidance, time savings, system reliability,<br />
and safety. NHTSA expects to continue to work cooperatively<br />
with its sister administrations within the<br />
Department of Transportation to assess the sal'ety impact<br />
of future field operational tests.<br />
Human Factors<br />
Since the last <strong>Conf</strong>erence our human factors program<br />
has included:<br />
. Work was complctcd describing the functional and<br />
pcrformance specifications for passive retroreflective<br />
marking systems that could bc addcd to<br />
heavy truck trailers to make them more conspicuous<br />
to other drivcrs at nisht.<br />
30<br />
. Two studies were completed to evaluate the<br />
performance requiremcnts necdcd for daytime<br />
running lights (DRL). Onc study cxanrined thc upper<br />
intensity limits needed to control glare from DRL in<br />
rearview mirrors, flnd the other involved collecting<br />
data on minimum intensity lcvcls needed to enhance<br />
vehicle conspicuity undcr daytime ambicnt light<br />
levels.<br />
. Research was continued on developing headlight<br />
system illumination requirements based on driver<br />
visibility needs and glare limits. We examined the<br />
ability of existing object detection models to predict<br />
driver capabilitics and arc dcveloping a computcrbascd<br />
analysis procedure to derive illumination<br />
requirements for a headlight systems.<br />
. Bccausc of concerns about the number of children<br />
struck by school buscs, rcscarch was undertakcn to<br />
dctcrminc human fflctors requirements for crossview<br />
convex mirrors.<br />
. A study was completed of the various human factors<br />
issues associated with foot pedal con[iguralions.<br />
This research was in response to concerns about<br />
"sudden<br />
acceleration" crashes that may have been<br />
caused by drivers hitting the accelerator instead of<br />
the brake.<br />
In addition, over the past year, the Agency<br />
implemented a comprehensivc human factors rcscarch<br />
program to support the expanding effort to develop<br />
<strong>Int</strong>elligcnt Vehicle/Highway Systems. The goal of the<br />
Agency's human factors program is to ensure that the<br />
IVH systems are suitably matched to thc capabilitics and<br />
limitations of thc drivers who must use the devices. An<br />
extensive series of studies are planned to quantify<br />
critical driver sensory, perceptual, and motor capabilitics,<br />
and to define and measure relevant mental and decision<br />
making capabilities and their interactive role in driving<br />
safety. The initial Agency initiativc includes:<br />
. A project to determine how best to present/display<br />
crash avoidance warning signals to drivcrs in ways<br />
that will ensure they understand them quickly and<br />
respond appropriately. A key issue to be addressed<br />
is whether standardized systcm function<br />
characteristics and display formats for each system<br />
are needed/appropriatc to avoid drivcr confusion.<br />
Also, in situations where multiple systernr; are<br />
employed, hierarchies will be dcveloped describing<br />
which systems should take precedence over others,<br />
so that compcting signals are not simultaneously<br />
presented to drivcrs.<br />
. A project to determine if real-time measurements of<br />
drivers' driving performance can be made and<br />
assessed as a basis for developing an in-vehicle<br />
monitor that could warn drivers of transient lapses in<br />
a driver's performance.<br />
. A project to dcyclop mcasurement techniques for<br />
assessing the extra workload imposed on drivers by
additional displays, warning signals, or other aids<br />
that are equipped on vehiclcs ostcnsibly to hclp<br />
drivers better navigate or control their vehiclc.<br />
. A projecl to develop standardized mcthods of<br />
measuring and evaluating the visual content and<br />
informational value of the direct and indircct visual<br />
ficlds of view out of a vchicle that are afforded<br />
drivers.<br />
National Advanced Driving Simulator<br />
NHTSA is assessing the merits of consEucting a<br />
National Advanced Driving Simulator (NADS) to support<br />
a national research program to achieve improvements in<br />
the transportation system through reduced crash rates,<br />
improved vehicle design, increased roadway efficiency,<br />
and expanded mobility for special populations such as<br />
elderly and handicapped drivers. Realistic high fidclity<br />
simulation would provide researchers with the ability to:<br />
(l) examine hazardous situations in great detail that<br />
cannot be evaluated in field test conditiotrs because of<br />
the possible safety hazard to test subjects, (2) exactly<br />
replicate conditions for a large number of subjects<br />
thereby enabling a genuine as$essment of the role of<br />
human factors in traffic safety, (3) acquire for thc first<br />
time accuratc mcasures of human rcsponse and control<br />
during critical crash situations, and (4) exercise precise<br />
experimental control of environmental conditions (ice,<br />
snow, fog, etc.), vehicle characteristics, and human<br />
characteristics. Research projects would focus on the<br />
complex interactions among the vehicle, the driver, and<br />
thc highway environment by means of multi-variate<br />
experiments that involvc operator-in-the'loop driver<br />
performance during critical driving situations.<br />
The technical feasibility and conceptual design study<br />
of the NADS has been completed. No lechnical barriers<br />
were identified in this analYsis.<br />
Two NHTSA-sponsored studies have been completed<br />
to identify the research needs of potential user groups'<br />
such as automobile and truck manufacturers. vehicle<br />
component suppliers, traffic safety engineers, highwiry<br />
designers, public health officials, human factors<br />
rcscarchcrs, and motor vehiclc administrators' Thcse data<br />
will be used as the basis for developing detailed<br />
functional design specifications tbr the simulator facility'<br />
In addition, the Transportation Rcsearch Board<br />
conducted an independent assessment of user needs'<br />
The National Science Foundation (NSF) provided<br />
assistance to the U.S. Dcpartment of Transportation in<br />
conducting a national competition among major<br />
transportation research universities to identify the<br />
qualified educational institution to host the NADS. NSF<br />
has provided the results of its efforts to the Departmsnt.<br />
Heavy Vehicle Research<br />
Heavy truck safety continues to draw a great deal of<br />
publicity and attcntion in the U.S. Heavy truck crashcs<br />
are not unduly frequcnt, hut aro often spectacular' Thcy<br />
Sectlon 2: Government Sfafus Bepons<br />
frequently result in fatalities, usually to occupants of<br />
other vehicles involved in collisions with trucks, and<br />
often lengthy traffic tie'up$ result. Current<br />
vehicle-rclatcd rescarch programs intended to reduce<br />
heavy truck crash and injury rates are focused on brake<br />
system performance, handling and stability, crashworthiness/aggressivity<br />
reduction, and humln factors.<br />
Five different tractor antilock systcms have bcen<br />
evaluated on the test track in a rnnge of braking and<br />
steering maneuvers. As a result of this efforl' we havc a<br />
much better understanding of the relationship betwccn<br />
cost/complexity and perftlrmance. The 2-year, in-service<br />
field evaluation of 200 antilock brake-equipped heavy<br />
truck tractors has been completed. Seventeen fleets, the<br />
seven major U.S. heavy truck manufacturers, ilnd the<br />
five suppliers of antilock brake systems, cooperatcd in<br />
this tcst involving vehicles based in six cold weather<br />
climate citics. Maintcnance rccords, data from a special<br />
on-board instrumentation system, and feedblck from<br />
drivers and mechanics were used to judge the reliability'<br />
durability, and maintairrability of thc systems. In 1990'<br />
the program was expanded to include the evaluation of<br />
antilock systems on 50 trailers.<br />
Thc Heavy Truck Subconrmittee of the Motor Vehicle<br />
Safety Rcscarch Advisory Committcc has becn very<br />
activc, forming two task Sroups, one on antilock brake<br />
test procedure development, the other on tire traction<br />
performance meilsurement. The antilock brake tcst<br />
procedures task force successfully conducted a series of<br />
round-robin tests flt several different industry and<br />
government test sites focusing on the issue of tcst<br />
surface variability.<br />
The tirc rcsearch task force pfesented a plan for an<br />
industry/government cooperative research plogramwhich<br />
the Agency is in the process of implementing. The<br />
first phase of the program involves developing<br />
standardized methotls of measuring and reporting truck<br />
tire traction performance. The second phasc will involve<br />
testing a wide of range of tires with the test procedure to<br />
develop a catalogue of data chiuacterizing the range of<br />
performance available from current tire designs.<br />
Light Vehicle Rollover Research<br />
Utility vehicles and light pickup trucks continue to<br />
make up an increasing share of the U.S. car market. At<br />
the same time, crash data stutJics conducted try NHTSA<br />
and others show that thcsc vchiclcs dcmonstratc an over<br />
involvement in rollover crashes. The crash data also<br />
shows that rollover crashes produce higher levels of<br />
fatalities and injuries. NHTSA has completed an<br />
extensive research progrflm to investigate thc causcs and<br />
possible solutions to light vehicle rollover crashes' As a<br />
part of this research effort, an extensive rollover crash<br />
database was constructed and validated with respect to<br />
such things as vehicle make/model identification, crash<br />
factor definitions, and data coding. A full scale vehicle<br />
test program was conductcd to reveal thc vchiclc factors<br />
3t
lSth lnternatlonal Technlcal <strong>Conf</strong>erence on Experlmentel Sefety Vehicles<br />
influencing rollover and to generate vehicle dynamics<br />
data for validating a vehicle handling simulation being<br />
used to study vehicle rollover. In addition, a statistical<br />
analysis of these rcsults was performed to assess or<br />
establish correlations between rollover rates and vehicle<br />
characteristics such as wheelbase and center of gravity<br />
location. Continuing rollover research at NHTSA will<br />
involve primarily additional statistical analysis of our<br />
rollover database to further define thc magnitude of the<br />
contributions of vehicle, driver, and environmental<br />
factors to vehicle rollover causation.<br />
Crashworthiness Research<br />
NHTS A's Crashworthincss rcscarch program currently<br />
focuses on three major crash modes for the protection of<br />
occupants of passenger cars, trucks, and vans: frontal,<br />
side impact, and rollover. The fundamental knowlcdge<br />
necessary for crashworthiness advances is obtained<br />
through our biomechanics research efforts. NHTSA's<br />
crashworthiness programs have successfully applied this<br />
scientific approach to achieve major advances in motor<br />
vehiclc safety such as air bag flutomatic crash protection<br />
systems. Crashworthiness advances prescntly bcing<br />
developed will further advance the state-of-the-art in<br />
vehicle design crash protection. The end result will be<br />
the developmcnt and application of cost-effective motor<br />
vchicle safety technologies that prcvcnt injuries and save<br />
lives.<br />
Crash Data Files<br />
NHTSA is using the National Accident Sampling<br />
System (NASS) and Fatal Accident Reporting Systems<br />
(FARS) crash data files to support the problem<br />
determination phase of its crashworthiness research<br />
projects. The NASS data contain very extensive detailcd<br />
information regarding each available case. For the<br />
various research projects, these data are being reviewed<br />
to identify thc number and types of injuries, the<br />
mechanisms causing the injuries, -tnd the associated<br />
crash conditions, and vehicle parameters.<br />
Also, NHTSA is continuing to utilizc the crash data<br />
files from individual States to supplement the FARS flnd<br />
NASS crash files. The Crashworthiness State Dfllabase<br />
(CWSD) currently consisting of thrce Statcs,<br />
Pennsylvania, Texas, and Indiana, has been developed to<br />
particularly support the crashworthiness prograrns of the<br />
Agency. These particular Statcs were selected because of<br />
the detailed information contained on make/model<br />
designation, body regions injured, injury source, and<br />
other important crashworthiness parameters.<br />
Frontal Crash Protection<br />
With the implementation of Federal Motor Vehicle<br />
Safcty Standard (FMVSS) No. 208, which requires<br />
automatic occupant protection in fronlal collisions,<br />
continuing research is focusing on identifying the<br />
remaining safety problcms for restrained occupants.<br />
32<br />
tffhile the lives and injuries which will be saved by this<br />
standard are substantial, it is estimated that, even after<br />
full implementation of this standard, frontal impacts will<br />
account for approximately 10,900 passenger car and light<br />
truck fatalities per year. Research has been initiated to<br />
investigate concepts to mitigate this safety problem<br />
including the evaluation ol' advanced automatic<br />
restraints, improved structural integrity, and improved<br />
energy absorbing interiors. Crash data, full scale crash<br />
te$ting, and analytical modeling are providing NHTSA<br />
insight into the magnitude of the problem and specific<br />
injury mechanisms.<br />
Crash environments being invcstigated includc higher<br />
speed impacts and offsct impacts which can result in<br />
high lcvcls of intrusion. Improvements to interior<br />
components such as the steering assembly, instrument<br />
panel, and pillars are continuing to bc tcstcd, especially<br />
as to their ability to rcduce hcad injuries.<br />
Side Impact Research<br />
The Agency's rcscarch program for the last several<br />
years culminated in the issuance of a Final Rule<br />
amending FMVSS No. 214 in Octobcr 1990. In this<br />
amendment, a dynamic test procedurc has bccn specificd<br />
for passenger cilrs to augment the static test procedure<br />
written to provide side door strength. Thc ncw dynantic<br />
test procedure establishes minimum requirements for<br />
thoracic and pelvic protection for near-side occupants in<br />
side impact crashes. Rescarch has bccn completed that<br />
demonstrates the specified protection levels can be<br />
achieved by structural modifications and/or the addition<br />
of side door padding. Even though thc ncar tcrm side<br />
thorax and pelvic impact research has been concluded,<br />
work has bccn continuing in both the analytical and<br />
testing area. Wc have developed a mathematical model<br />
for simulating passengor car side crashes. This model has<br />
been extensively used in paramclric studics and<br />
countcrmcasure cvaluation. We are extending this model<br />
to simulatc light truck crashes.<br />
Light truck testing was initiatcd in 1988. Wc are<br />
currently using the amended FMVSS No. 214 dynamic<br />
test procedure to continuc sidc impact tcsting of light<br />
trucks and vans in ordcr to develop baseline data on<br />
these vchicles. Particularly, we are focusing on light<br />
trucks and vans (LTVs) in which the seated height of the<br />
occupant is similar to that of passenger cars.<br />
Even with the upgrade of FMVSS No. 214 to address<br />
the thoracic and pelvic injuries, head injury remains as<br />
a major contributor to the fatal harm experienced in side<br />
crashes. Unfortunately, even survival of a head injury is<br />
frequently debilitating. NHTSA disability studies show<br />
that 50 percent of the medium term cognitive impairment<br />
is due to contact with thc A-pillar and roof rails.<br />
Our upper interior head proteclion research program<br />
secks to improvc head prolection in occupant head<br />
impacts with the upper interiors of passenger vehicles.<br />
The upper interior is defined to be the side roof rails, the
front header rails, and the A/B-pillars. Since the last<br />
conference, thc research program has achicved several<br />
important milestones. As a result of this program, an<br />
updated analysis of the U.S. crash data was done and we<br />
now estimate that, in 1989, head impacts with the upper<br />
intcrior claimed the lives of an estimated 4,000 persons<br />
and left anothcr 9,300 occupants with scrious head<br />
injury. The program has developed a promising<br />
component level head impact test proccdurc which has<br />
been extensively validatcd in sled tcsts. Most recently,<br />
the program has complcted a characterization of head<br />
injury potential across a sample of the U.S. passenger<br />
car and LTV fleet. We have found that head impact<br />
injury potcntial is a strong function vehicle design, and<br />
protection varies widely from vehicle to vehicle.<br />
Minivans and vans appcar to havc designs which yield<br />
scvere responses. Howcver, padding the upper interior<br />
was found to be a feasible and exceptionally effective<br />
method of reducing head injury potcntial.<br />
Ejection Reduction P ro gram<br />
Approximately 9,300 people are killed each year on<br />
U.S. highways as a result of ejection from passenger cars<br />
and light trucks. Of these, about 3,300 iue ejected<br />
through the side doors. NHTSA has conductcd studies of<br />
crash-involved vehicles where door latch failures rnay<br />
have occurred in order to understand the failure<br />
mechanisms in crashes. A numbcr of tcsts have been<br />
conductcd to determine the ultimate strength of latches<br />
on various makes and modcls of vehicles using procedurcs<br />
in the current door latch safety standard. To<br />
date, there has been no strong correlation found between<br />
openings and the measured latch strength. New tcst<br />
procedures are being developed to mimic the combincd<br />
longitudinal and lateral loadings thc door latch was<br />
observed to have experienced in a recent review of<br />
crashes involving door openings. This combined loading<br />
provides a more realistic representation of the latch<br />
failures seen in the real world crash experience.<br />
Rollover Research<br />
Our rcscarch in crashworthiness rollover protection<br />
has emphasized a refincd definition of the problem, the<br />
development of improved test dcvices, and analytical<br />
techniques. Experimental testing has continued to<br />
concentrate on the crashworthiness of LTVs in a<br />
controlled rollover event. These were recently conducted<br />
on small pickup trucks to a$$ess the structural integrity<br />
of the vehicles. We have initiflted finite element<br />
modeling of the roof structure to explore possible design<br />
changes which would improve the roof structure<br />
performance and to dctcrmino its effect on restrained<br />
occupant injury. Wc havc also continued to improve our<br />
rollover simulation capability by improvements to the<br />
Articulated Total Body (ATB) occupflnt simulator.<br />
Advanced restraint system conccpts are being explored<br />
with the ATB model.<br />
Sectlon 2: Government gtatus Repons<br />
Biomechanics Research<br />
Thc primary pursuits in the area of biomechanics<br />
continue to be efforts in impact injury research directed<br />
toward increasing our understanding of injury<br />
mechanisms, development and application of unique<br />
instrumentation necessary to capture and characterize the<br />
mcchanical conditions of injury that convcntional<br />
inslrumentation cannot measure, application of tinite<br />
element modcling technology toward dctailed structural<br />
modeling of thc human, and thc efforts to translatc this<br />
knowlcdge into physical test devices that will enhance<br />
our ability to assess and ameliorate the hazards of the<br />
automotive crash.<br />
Impact injury research activities are now being<br />
pursued at three NHTSA-sponsored Impact Injury<br />
Research Centers: the University of Virginia, the<br />
Medical College of Wisconsin, and the University of<br />
Heidelberg. These centers have now fully implemented<br />
the NHTSA-developed deformation measuring<br />
methodology which can determine the cross-sectional<br />
geometry of the thorax during impact cvcnts and are<br />
investigating the pcrforrnancc of various safety systems<br />
in frontal impacts. The grcatcr dctail of the actual<br />
deformations of the thorax during irnpact provided by<br />
this instrumentation promises to give greater insight into<br />
the injury mechanisms at work in frontal impacts, which,<br />
in turn, should providc more definitive means and<br />
methods of evalurting accurately the saf-ety of vchicles<br />
in the fulurc.<br />
Efforts to apply the finite element tcchnology to the<br />
detailed modeling of anatomical slructurcs arc<br />
continuing. In addition to ongoing cllorts to dcvclop<br />
detailed anatomical models of the brrin/skull and the<br />
complete upper torso, development of a cervical spine<br />
model has also been undertaken. These modcls. when<br />
fully dcvelopcd, will be capable of simulating, for the<br />
variety of automotive crashes, hoth the impact response<br />
and thc typc, location, and severity of any expected<br />
injuries.<br />
We have completed the design, development and<br />
construction of the first prototype of NHTSA's advanced<br />
test dummy thorax. This design has achicvcd grcatcr<br />
thoracic anatomical similarity than current dummies by<br />
extencling the lower rib cage and improving the shoulder,<br />
spine, and clavicle structure. It possesses more realistic<br />
regionrl stiffness characteristics to insure proper<br />
interaction with safcty bclts and air btgs and has<br />
improved impact response fidclily wtrilc rcducing<br />
temperature sensitivity and matcrial dcpendcncc. An<br />
initial design evaluation effort will start shortly, and we<br />
hope to involvc as many intcrcstcd organizations as<br />
possible. Efforts also continue on thc devclopmcnt of an<br />
advance neck which will prescnt thc hcad to possible<br />
impact points with a more correct attitude and velocity,<br />
as well as mimic observed human responscs more<br />
accuratelv than current neck svstems do.
lSth tnternetlonel TeChnlcal <strong>Conf</strong>erence on Experlmental Safety Vehlcles<br />
Highway Safety Research<br />
NHTSA's behavioral research program continues to<br />
concentrate on alcohol and drug impaired driving and<br />
occupant protection. In addition, we have devcloped a<br />
research plan on ways to improve the safety and mobility<br />
of older drivers and pedestrians in response to the rapid<br />
expansion of this segment of our population.<br />
Alcohol and Drug Safety Research<br />
During the last decade, our alcohol research program<br />
has developcd, tested, and evaluated specific counter'<br />
mcasure techniques and strategies such as eye gaze<br />
nystagmus, license suspension, and comhined enforcement<br />
and publicity programs. Many of thesc tcchniques<br />
were found to be cttcctive and are used in States and<br />
communities around the nation.<br />
Our current alcohol research emphasizes four areas:<br />
. Norms Development. We are idcntifying changes<br />
that have to be made in attitudes, knowledge,<br />
motivations, etc., to gain wider acceptance of ANTI'<br />
DWI standards of behavior; as well as studying ways<br />
of inducing these changes.<br />
. Youth. We are investigating and evaluating the<br />
effects of strategies such as special sanctions for<br />
youth who drive after consuming alcohol and<br />
programs to support the 2l minimum drinking agc'<br />
' Detcrrcnce. We are studying the effects of specific<br />
sanctions for driving while intoxicated, including<br />
vehicle and license plate impoundment and insurance<br />
sanctions.<br />
. Community Traffic Safety hograms. We are<br />
devcloping methods to support alcohol and other<br />
traffic safety programs at the community level.<br />
Our drug rescarch seeks basic knowledge on thc<br />
influence of drugs in traffic safcty. We are assessing the<br />
incidence and role of drugs in fatal traffic crashes and<br />
arc measuring the effccts of different doses of specific<br />
drugs in a driving simulator and in on-the-road driving'<br />
Safety BeIt tlse Research<br />
The first safety belt use law in the United States<br />
became effective in the State of New York in December<br />
1984. At the time, belt usc (as measured by our survey<br />
of passenger car drivers in 19 U.S. cities) was 15<br />
percent. At the May 1987 <strong>ESV</strong> meeting, we reportcd that<br />
24 States and the District o[ Columbia had passed beltuse<br />
laws and belt use had rcached 42 percent. Our report<br />
at the 1989 meeting noted laws in 33 States and the<br />
District of Columbia and belt use at 47 percent. We are<br />
pleased to rcport continued passage of State belt-use<br />
laws: we now have laws in 4l States and the District of<br />
Columbia. Earlier this year, NHTSA embarked on a<br />
program, in partnership with the States, to increase<br />
safety belt use to 70 percent by the end of 1992 through<br />
a combination of public information and belt law<br />
enforcement. Our l9-city survey results now show belt<br />
34<br />
use at 54 percent, but use determined from State surveys<br />
is 59 percent.<br />
NHTSA's current research on occupant protcction<br />
spans several areas: (1) completing dcmonstrations of<br />
integrating safety-seat and belt-law enforccmcnt and<br />
public information into regular police activitiesi (2)<br />
identifying characteristics of population subgroups<br />
involved in fatal crashes in order to develop more<br />
effective stratcgics for reaching these groups with betterdefined<br />
messages; (3) developing program strategies for<br />
identified target groups such as part-time users and<br />
parents of young children. We continue to monitor belt<br />
use trends and provide assistance to in designing,<br />
conducting, and analyzing belt observation surveys.<br />
Motorcycle helmet use is now required for all<br />
motorcyclists in 24 States and the District of Columbia.<br />
Motorcycle driver helmct use observed in thc l9-city<br />
survey shows that, in cities covered by State helmct-use<br />
laws, nearly all drivcrs are helmeted. In citics not<br />
covered by laws, howcver, fewer than 50 pcrcent of<br />
drivers wear helmets.<br />
Older Drivers and Pedestrians<br />
Our older driver and pcdestrian research is aimed at<br />
reducing crash risks without unduly restricting pcrsonal<br />
mobiliLy. We have examincd existing Stilte liccnsing<br />
requirements and proccdures that apply spccifically to<br />
older drivers, especially testing rcquirements based on<br />
advanced age alone, and the use of rcslricted licenses for<br />
drivers with marginal qualifications. Working with the<br />
American Association of Motor Vehicle Administrators,<br />
we havc contributed to thc development of model<br />
licensing regulations for older drivcrs. We have<br />
completed development of information programs for<br />
oldcr pedestrians and are studying the conccpt of<br />
creating safety zones around housing areas for our older<br />
citizens.<br />
We are currently analyzing data obtainetl from a<br />
cooperative study with the National Institute on Aging<br />
relating health status, driving practices, and crash<br />
experience of older persons. Our long-tcrm research is<br />
dirccted toward devcloping methods for dclccting<br />
problem older drivers and providing guidance for<br />
physicians, occupational therapists, family members, and<br />
licensing officials in assisting oldcr drivers make<br />
appropriate decisions about driving.<br />
Rulemaking<br />
Since our last meeting in Sweden, NITTSA's rulemaking<br />
activitics have resulted in 26 regulations or<br />
proposed regulations. Eighteen of these were in thc area<br />
of crashworthiness, while eight were rclated to crash<br />
avoidance. Some of the more noteworthy actions were<br />
the extension of the passengcr car Occupant Crash<br />
Protection standard (FMVSS 208) to light trucks, the<br />
amendment to FMVSS 214 (Side Impact Strength) to<br />
include dynamic performance tests requirements in
addition to static test requirements for passenger cars-<br />
Standard 214 was later amended for extension to light<br />
trucks. The following represents the actions taken by<br />
NHTSA since May of 1989.<br />
Crashworthiness:<br />
. On June 14, 1989, a Final Rule was published<br />
adding the requirement to FMVSS No. 208' "Occupant<br />
Crash Protection," that lap/shouldcr belts be<br />
installed at all forward-facing reilr outboard seating<br />
positions in passenger cars. The purpose of the rulemaking<br />
was to provide more crash protection to rear<br />
seat occupants that than that of the previously<br />
required lap belts. The effective date was December<br />
11, 1989.<br />
. On September 25, 1989, a Final Rule was published<br />
extending FMVSS No. 202, "Head Restraints," to<br />
light trucks. The purpose of the rulemaking was to<br />
reduce the frequency and severity of neck injuries in<br />
light trucks. Thc effectivc date was September I'<br />
199 1.<br />
. On November ?, t989, a Final Rule was published<br />
extcnding the rear seat lap/shoulder requirement of<br />
FMVSS No. 208, "Occupant Crash Protection," to<br />
light trucks. The purpose of the rulcmaking was to<br />
create more effective crash protection for rear seat<br />
occupants in light trucks. The effective date was<br />
September I, 1991.<br />
. On December 21, 1989, a Notice of Proposed<br />
Rulemaking (NPRM) was published establishing<br />
performance requircments for automatic locking<br />
retractors in seat bclt systems, in FMVSS No. 208'<br />
"Occupant<br />
Crash Protection," for trucks, buses, and<br />
multipurpose pa$senger vehicles over 10,000 pounds<br />
gross vehicle weight rating (GVWR). The purpose<br />
for the rulemaking was to make these seat belt<br />
systems more comfortable, and thus increase the<br />
usage. The effectivc date was May 28, l99l'<br />
. On July 26, 1990, a Final Rule was published<br />
amending the Agency's specifications for the 3'yearold<br />
child test dummy used to tcst child restraint<br />
sy$tems. Specifications are provided for a new head<br />
with a higher natural frcquency response and for two<br />
different types of accelerometers which may be used.<br />
The effective date was May 28, 1991.<br />
. On October 30, 1990, a Final Rule was published<br />
amending FMVSS No.214, "Side<br />
Impact Strength,"<br />
to include dynamic perforntance test requirements, in<br />
addition to static test requirements, for passenger<br />
cars. The effective date was Novcmber 29' 1990'<br />
. On January 29, 1991, a Final Rulc was published<br />
amending FMVSS No. 208, "Occupant<br />
Crash Protcc'<br />
tion," so that manufacturers would have the option<br />
to use the automalic safety belt warning systems in<br />
passenger cars equipped with manual belts- The<br />
warning system for cars equipped with manual bclts<br />
Sectlon 2: Government Sfatus Reports<br />
is not as stringent as the one for automatic belts. The<br />
effcctive datc was January 29, l99l'<br />
. On March 15, 1991, a NPRM was published proposing<br />
to enhancc the objectivity and applicability of<br />
school bus joint strength requiremcnts and tcst procedures<br />
in FMVSS No.22l, "School<br />
Bus Bodv Joint<br />
Strength." Its purposc is to clarify and expand<br />
procedures for testing the strength of school bus<br />
body joints.<br />
. On March 15, 1991, a NPRM was published proposing<br />
to increase thc minimum emergency exit space,<br />
based on the capacity of the bus, in FMVSS No.<br />
217, "8us Window Retention and Relcase"'Thc proposal<br />
would also require school buses to provide<br />
irnprovcd access to side emorgency doors.<br />
'On April 16, 1991, a Final Rulc was published<br />
amending FMVSS No. 208, "Occupant<br />
Crash Protection."<br />
and No. 209,<br />
"Seat<br />
Bclt Assemblies"' to eliminate<br />
the static testing requircments for safety bclts<br />
that are dynanrically tcsted. This has been antended<br />
because the dynamic test nrore accuratcly reflects the<br />
occupant protcction in a crash. The effective date<br />
was April 16, 1991.<br />
. On June 6, 1991, a Final Rule was published amending<br />
FMVSS No. 201, "Occupant Protection in<br />
<strong>Int</strong>erior lmpact," to alter the requirements concerning<br />
the instrumcnt panel for vehicles with passengerside<br />
air bags. The purpose of thc rulemaking is to<br />
encourage greater availability of such air bags. The<br />
effective date was July I, 1991.<br />
. On February 19, 1991, a NPRM was published<br />
proposing to modify FMVSS No' 213' "Child<br />
Restraint Systems," to require manufacturers of child<br />
safety seats to providc a postage paid registration<br />
form to first purchasers of the seats.<br />
. On March 21, 1991, a Final Rule was published<br />
extending the front-seat automntic crash protcctlon<br />
requirement of FMVSS No. 208, "Occupant Crash<br />
Protcction," to light trucks. The rule will be phascd<br />
in during the model years 199-5-1997 and will be<br />
fully effective in the model ycar 1998.<br />
. On April 16, 1991, a Final Rule was published<br />
extending FMVSS No. 216, "Roof Crush Resist'<br />
ance," to light trucks of 6000 pounds or less GVWR-<br />
The purposc of the rulemaking is to resist intrusions<br />
in the roof by providing crush resistance. Thc<br />
effective date is Septcnrber I, 1993.<br />
. On June 10, 1991, a Final Rule was published<br />
extcnding FMVSS No.2l4,'-Side Door Strength," to<br />
light trucks. The purposc of the rulernaking is to<br />
resist intrusions in side doors by providing crush<br />
resistance. The effectivg date is September I' 1993.<br />
' On July 17, 1991, a notice was published announcing<br />
the publication by NHTSA of a planning document<br />
that discusses planned rcsearch and possible<br />
upgrades to FMVSS No. 213, "Child Restraint<br />
systems."<br />
35
lSth lnternailonel rechntcel conference on Expertmentat setety vehtctes<br />
. On August 12, 1991, a NPRM was published proposing<br />
modifications to the seat adjustment requirements<br />
of FMVSS No. 2L3, "Child Restraints<br />
Systems."<br />
. On August 12, 1991, aNPRM was published proposing<br />
adding a newborn infant test dummy to part 572.<br />
The issue of using the dummy in FMYSS 2l 3 testing<br />
will be explored in future rulemaking.<br />
Crash Avoidance:<br />
. On June 29, 1989, a Final Rule was published<br />
amending FMVSS No. 108, "Lamps, Reflective<br />
Devices, and Associated Equipment," to include an<br />
additional type of standardized replaceable light<br />
source to be used in replaceable bulb headlamps on<br />
motor vehicles. The effective date was July 31,<br />
1989.<br />
. On April 9, 1990, a Final Rule was puhlished<br />
amending FMVSS No. 108, "Lamps, Reflcctive<br />
Devices, and Associated Equipment," to include an<br />
additional type of standardized replaceable light<br />
source to be uscd in replaceable bulb for headlamp<br />
systems on motor vehicles. The effective date was<br />
May 9, 1990.<br />
. On March 26, 1991, a Final Rule was puhlished<br />
which replaced the existing FMVSS No. 102,<br />
-'Transmission<br />
Shift Lever Sequence, Starter<br />
<strong>Int</strong>erlock, and Transmission Braking Effcct,"<br />
requirement that there must be permanent display of<br />
gear position information for automatic transmission<br />
vehicles which do not have a gear shift lever park<br />
position. This Final Rule requires display of gear<br />
position information only when the ignition is in a<br />
position capable of operation. Thc effective date for<br />
the deletion of the old requirement wfls April 25,<br />
1991. The effective date for the amendment was<br />
September 23, 1991.<br />
. Ott April 10, 1991, a Final Rule was published<br />
extending the center high-mounted stop lamps<br />
requirement of FMVSS No. 108,<br />
--Lamps,<br />
Rcflective<br />
Deviccs, and Associated Equipment," ro light trucks<br />
with a GVWR of less than 10,000 pounds. The rulc<br />
is optional as of September l, 1992, and mandatory<br />
as of Scptember l, 1993.<br />
. On April 19, 1991, a Supplemental NPRM (SNPRM)<br />
was published proposing that FMVSS No. 108,<br />
"Lamps,<br />
Reflective Dcvices, and Associated<br />
Equipment," be amended to allow the physical<br />
combination (but not the optical combination) of the<br />
centcr high-mounted stop lamp with cargo bed lamps<br />
on vehicles other than passengcr cars.<br />
. On May 2,1991, a NPRM was published proposing<br />
that FMVSS 111, "Rearview Mirrors," be amended<br />
to increase the field-oFview around school buses.<br />
This could be accomplished either by direct view or<br />
by mirrors.<br />
36<br />
. On May 3, 1991, a Final Rule was published<br />
establishing a new safety standard requiring ncw<br />
school buses to be equipped with a stop signal arm.<br />
The intended effect of this rule is to reduce the risk<br />
to pedestrians near stopped school buses. The<br />
effective date is September l,1992.<br />
. On May 3, 1991, a NPRM was publishedproposing<br />
two alternative amendments to the requirements of<br />
FMVSS No. 121, "Air Brake Systems," concerning<br />
electrical power systems. The first alternative is that<br />
trailer antilock systems would be required to be<br />
powercd by a separate electrical circuit, with the<br />
stop lamp circuit being used as a source of backup<br />
power. Under thc second alternative, the Agency<br />
would rescind the cxisting requirement that lrailer<br />
antilock systems bc powered from the stop lamp<br />
circuit. The reason this rulemaking is being<br />
undertaken is that thc Agency is concerned that<br />
requiring antilock systems to be powered from the<br />
stop lamp circuit inhibits some state-of-art trailer<br />
antilock systems.<br />
<strong>Int</strong>ernational Harmonization<br />
Finally, in closing, it is appropriate to restate<br />
NHTSA's ongoing commitment to fostering worldwide<br />
harmonization of motor vehiclc salety standards to the<br />
maximum extent practicilble. This policy is, of course,<br />
governed by applicable U.S. laws and procedural<br />
requirements, and by our ovcrriding concern that tho<br />
current level of motor vehicle safety in the United not be<br />
degradcd.<br />
Efforts toward greater harmonization have been<br />
conccntrflted in the areas ofbrakes. lighting systems, and<br />
side impact protection for passenger car occupants. Also,<br />
during the past few ycars, we have also become rnore<br />
involved in fostcring institutional changes to facilitate<br />
worldwide harmonization. The following arJdress<br />
progress in each of thcse areas sincc the lzth <strong>ESV</strong><br />
<strong>Conf</strong>erence.<br />
B rake s<br />
The effort to harmonize brake standards for paisenger<br />
cars on a worldwide basis began in the carly 1980's. At<br />
the last <strong>ESV</strong> <strong>Conf</strong>crcnce, we reportcd that the issues of<br />
a test procedure for measuring adhesion utilization might<br />
be resolved by the use of a simple wheel lock sequence<br />
test as a screening test with thc use of torquc wheels as<br />
backup. We furl.her indicated that such a test procedure<br />
was being evaluated and thc rcsults would be discussed<br />
in informal scssions of the Meeting of Experts on Brakcs<br />
and Running Gear (GRRF) of the Economic Commission<br />
for Europe (UN/ECE).<br />
The resulls of those discussions and the review of<br />
comments to the previous Supplemental Notice of<br />
Proposed Rulemaking (SNPRM) lcd the Agcncy to<br />
further revise and refine the test proccdures and
performance requirements and to publish a new SNPRM<br />
in July, 1991. It is r-rur tcntative conclusion that this new<br />
SNPRM will achieve the goals of harmonization while<br />
bcing fully consistent with the requircments of our<br />
lcgislation. The comment period, originally set to end on<br />
October 31. 1991. has been extended to January 10,<br />
1992, to provide for the consideration of additional test<br />
data to be submitted.<br />
Lighting .Sysrems<br />
At the last <strong>ESV</strong> <strong>Conf</strong>erence we reported on the status<br />
of several proposals that hild been made to thc ECE for<br />
further harmonization of lighting standards. At thtt time'<br />
proposals concerning the permittcd tnaximum intensity<br />
of yellow rear turn signals and of stoplamps and the<br />
amendment of appropriate ECE Rcgulations to pcrmit the<br />
approval of certain replaceatrle headlanrp trulbs had<br />
progressed, but were yet to reach fruition.<br />
Given the agreement by the Working Ptrty on the<br />
Construction ot Vehicles (WP29) that harmonizcd<br />
standards need not be identical stlndards, but standard<br />
that provide corridors of ovcrlapping performflnce or<br />
windows of compliance, flgreement was reached on<br />
permitting higher intensity levels for yellow rear turn<br />
signals and stopltmps in responsc to U.S. actions<br />
concerning the minimum intcnsity levels. The<br />
appropriate ECE regulations have been amended to<br />
permit the U.S. HB-3 lnd HB-4 bulbs while FMVSS 108<br />
has been amended to pcrmit the HB-Z bulb (a closcr'<br />
tolerance European H-4 bulb). Also, wc have been<br />
petitioned to amend FMVSS No. 108 to permit the<br />
European H-7 replaceable headlamp bulb. The petition is<br />
under consideration and a decision concerning rule'<br />
making will be mude early next year.<br />
Our proposals concerning center high-mounted<br />
stoplamps is still under active considcration within the<br />
Meeting of Experts on Lighting and Light-Signalling<br />
(GRE). We have reached agreement on the harmoniz.ation<br />
of vertical installation requirements t'or lighting<br />
systems, and work on harmonization of horizontal<br />
installation rcquirements and harmonizcd low beam<br />
France<br />
George Dobias<br />
Institut National de Recherche sur les<br />
Transports et leur Sdcuritd<br />
Since 1989, the picture of road safety in France has<br />
slightly improved, despite a significant increase of road<br />
traffic, especinlly for inter-urban travel. Howcvcr, a<br />
slowing down in this trend has treen noticeilble sincc the<br />
end of 1990.<br />
While the number of accidents as well as the number<br />
of injured pcoplc decreascd during this period, the<br />
Secfion 2: Government Sfatus Heports<br />
photometric continues. The ECE has adopted il new<br />
regulation on optiorral side marker lanlps that sets<br />
intcnsity and color regulltions that arc not in total<br />
agreement with those we would have preferred but which<br />
nevertheless will enable compliance by a wide rangc of<br />
vehicle designs.<br />
Side Impatt Protection<br />
NHTSA's final rule on upgrading FMVSS No. 214'<br />
"Side<br />
Door Strength," was issued in October, 1990. The<br />
amendment establishes chest und pelvic injury criteria to<br />
be used in full-sclrle crash tests. In its notice' NHTSA<br />
addressed the question of harmonization with Europe and<br />
noted the diffcrences in thc ntovable barrier (the LJ.S'<br />
barrier being heavier and representiltive of passcnger<br />
cars and light trucks likely lo be the striking vehicles in<br />
thc U.S.) and lhc availability of the EUROSID (side<br />
impact durnmy) ilt that time, and the uncertitinty, also ilt<br />
that titne, as to whether Europe would adopt<br />
requirements based on a full scale dynatnic crash test.<br />
Thc Agency notcd further that as Europe contittued to<br />
develop its standartl and test procedures, it would<br />
considcr whether further rulemaking is appropriatc.<br />
Progrcss on development of alternttive side impact<br />
dunrnties, the EUROSID heing onc oI them, is pronrpting<br />
the Agency to issue an advitnccd notice of proposed<br />
rulemirking on the subject in the vcry near future.<br />
Insilruilonal Matters<br />
Finally, the United St:ttcs has been vcry active in the<br />
proccss ol'reviewing nnd revising the "1958 Agrecment<br />
Concerning the Adoption of Uniform Conditions of<br />
Approval and Reciprocnl Recognition of Approvirl tor<br />
Motor Vehicle Equipment and Parts." The Agrcenrent<br />
provides the process by which ECE Regulittions are<br />
ildot)tcd and amendcd. The currcllt review is airned at<br />
providing il proccss thitt is rcflcctive of the world<br />
situittion in the ilulonlotive sector and which will serve<br />
the goals ol' aulotrtotivc safety and improved environment<br />
for thc coming years.<br />
numbcr of derths was reduced by only a small amount;<br />
thus risk exposure goes on decreasing while acciclcnt<br />
scvcrily rrteilsurcd by the ratio: nunrber ol deaths/nurttber<br />
of ucciclcnts goes on incrcasing. This negative evuluation<br />
appeflrs relatcd to the lrehaviour of younger drivcrs<br />
driving sporty and powcrlul cars, to the increilse in the<br />
numtrer of ntotortrikes and likcly in the number of hcavy<br />
goods vehicles.<br />
The following diagrtms illustrate this evaluation<br />
which is not specific to France.<br />
The progress trrought in national and local road safety<br />
policies, whether they dctl with the drivcr, the vehicle,<br />
37
1lth <strong>Int</strong>ernetlonal Technlcal conference on Expertmentat sefety vehictes<br />
ffi<br />
E s<br />
F<br />
F m<br />
E'"<br />
{<br />
tm<br />
CHAflIIE tr.I TIS ITIJIIBER OF FATALITIES<br />
rc ?1 2 t! 14 1J 16 n ?8 T & 81 8t 83 & it tu 87 88 S9 m Yeffi<br />
CIIANGE IN TTIE SERIOUSNESS OF ACCIDENTS<br />
(DEATHS PI1R IOO ACCIDENTS)<br />
CHANGE IN THE NTJMBBR OF DEATHS<br />
BY TT{DEX OF TR1FFIC FLO1V<br />
F<br />
Yem<br />
fr TtnnA frfr n ?tt mrr E ts F ot s tu &q Yls<br />
the infrastructure or the traffic conditions explain the<br />
stated improvements.<br />
. With regard to the driver, training conditions have<br />
been renewcd on the basis of the National Training<br />
Program devised by INRETS following a request by<br />
the Ministry of Transport. Application programs<br />
have becn built and driving school teachers arc now<br />
being trained. The originality of this program lies<br />
within the introduction of some training on car use<br />
conditions as well as on possible risk situatitlns the<br />
future driver might have to face.<br />
Simultaneously, the anticipated learning of the<br />
driving from the age of 16, with the presence ol'an<br />
experienced driver aboard the vehiclc, was extendcd<br />
to the whole French territory. First rcsults seem very<br />
promising and the younger drivers, training in this<br />
way, have 4 to 5 times less accidents than others.<br />
At last, the point demerit will be introduccd<br />
starting from June 1992, with an initial capital of 6<br />
points which, for cach recorded offense, will be<br />
diminished by a number of points depcnding on the<br />
severity of offense. It will be possible to replenish<br />
one's points capital by undergoing a specific<br />
training. Such training is now being experimented.<br />
. Regarding the vchicle, the most important measure<br />
is the introduction, from January l, 1992, of a<br />
periodical technical inspection, in accordancc with<br />
the usual practice in other European countrics. Seat<br />
belt use for rear passengers was also madc<br />
mandatory on Deccmber I, 1990. The effects of such<br />
a mcasure remain to bc cvaluated.<br />
' Thc improvement of road inliastructures has mainly<br />
dealt with:<br />
- the extension of the network of motorways,<br />
infrastructures providing the highest lcvel of<br />
safety, with a ncw master plan aiming at adding<br />
4,000 km to the existing network;<br />
- the continuation of thc trefltment of accidcnt black<br />
spots, with a markedly increased budget for the<br />
fiscal ycar 1991;<br />
- many actions within cities aimed at opposing<br />
physical limitations to traffic speecl.<br />
' The main meflsure regarding road traffic was to<br />
lower thc usual speed limit within cities from 60 to<br />
50 kmph. Some roads may be posted at 70 kmph and<br />
othcrs at less than 50 krnph (cspecially in rcsidcntial<br />
neighborhoods) through a Mayor's decision.<br />
The State has been going on with its policy of inccntives<br />
towards local fluthorities through the promotion of<br />
various programs such as road safety plans at the<br />
--department"<br />
level or "Villes plus sures" (Safer Cities).<br />
In the research and dcvelopment ficld, France<br />
participated in various EEC or European programs. For<br />
example, DRIVE I and DRIVE 2 aimed at promoring the<br />
use of telematics and information technologies in orrler<br />
to enhance travcl safety and el'llcicncy. Various field<br />
trails dealing with corridor traffic control (CORRfDORS)<br />
or urban network traffic control (POLIS) should bc<br />
conducted in France within the DRIVE 2 framework.<br />
French car makers are involved in the EUREAK,<br />
PROMETHEUS and CARMINAT projects, rhc goal of<br />
which is to develop equipment for the road-vehicle/<br />
vehicle-vehicle communications and for road guidance.<br />
The French Government decided on October 23, 1991,<br />
to launch a rcscarch and development program called<br />
--Vehicules<br />
et securite routiere" (Vehiclcs and Road<br />
Safety). This program, jointly sponsored by car-makers<br />
and INRETS, is pursuing scveral objectivcs:
. better knowledge of accidents and recent trends with<br />
an important research program iuound accidentology;<br />
. better prevention of accidents, through the developmcnt<br />
of new driving aids;<br />
r better protection of car occupants while considering<br />
the structural aggressivity of opponent vehicles and<br />
exploring new means of protection for collisions<br />
occurring at higher speeds.<br />
This work will concern both passenger cars and heavy<br />
goods vehicles and should lcad to the production of<br />
experimental vehicles, which is in line with the very<br />
philosophy of the <strong>ESV</strong> conferences. One component of<br />
the program will be madc up of socio-economic research<br />
aimed at the results assessment with regard to the needs<br />
and stakes, at checking public acceptance of driving aids,<br />
and at promoting a closer partnership between all the<br />
parties involved in road safety.<br />
Consequently, the program is aimed at the development<br />
of:<br />
. detectors of loss of alertness, devices for stopping<br />
against an obstacle, warning devices on elements<br />
crucial for safety;<br />
. priority ranking of warning systems;<br />
. systems to actively manage vehicle's behaviour and<br />
road/vehicle interaction (simultaneous managcmcnt<br />
of braking, steering, suspension functions balancc in<br />
crilical situations).<br />
Rescarch is to bc carried on:<br />
' improving visual perception of environment and<br />
signing:<br />
. alerting the driver by continuous monitoring of<br />
vehicle functions;<br />
. improvement of vehicle dynamic behaviour;<br />
Sectlon 2: Governm€nf Status Reports<br />
. data transmission between roadside equipment and<br />
the vehicle;<br />
' the effect of traffic on vehicle interactions.<br />
The research program is to focus on road user and car<br />
occupant protection, dealing mainly with the following<br />
points;<br />
. reduction in severity of frontal impacts against a<br />
fixed obstacle and of lateral and lrontal irnpacts<br />
between vehicles;<br />
. to improve safcty in crashes, i.e., optimization of<br />
energy absorption of seat structures and higher performance<br />
of seat/restraint device systems;<br />
. roacl user and car occupant protection in impacts<br />
with hcavy goods vehicles;<br />
. design of restraint devices for children of various<br />
ages;<br />
'improvement of vehicle dynamic behaviour by a<br />
better design of chassis structure (modelling,<br />
testing), braking and stccring;<br />
. reducing the aggressivity of hcavy vchicles;<br />
. design of driving and monitoring aids: real time<br />
dynamic monitoring (stability and trajectory,<br />
vigilance detectors) with priority for motorcoachcs<br />
and vehicles carrying hazardous cargo.<br />
Another component of this program is thc dcvelopment<br />
of il range of driving simulators to bc uscd in cars<br />
and heavy vehicle drivcrs' lraining, which will take<br />
advantage of the achievements of the large driving<br />
simulator being built jointly by PSA, RENAULT and<br />
INRETS.<br />
Lastly, in March 1991, a Forum of European Road<br />
Safety Research Institutes (FERSI) was established to<br />
promote a joint scicntitical approach of road safety<br />
related issues.<br />
.;t<br />
'.1<br />
;l
<strong>Section</strong> 3<br />
Technical Sessions<br />
Technical Session I<br />
Crash Investigation and Data Analysis<br />
Chairperson: Fred Wegman, The Nctherlands<br />
st.o.02<br />
Advanced Accident Data Collection-Description and Potentials of a<br />
Comprehensive Data Collection System<br />
Kamren B, v Koch M, Kullgren A' Lie A'<br />
Nygren A, Tingvall C<br />
Folksam Research, Chalmers University of<br />
Technology<br />
Abstract<br />
The most important input for developntent and<br />
evaluation of crash protection is real life accidents data.<br />
The dala is however time consuming to collcct and the<br />
output is in relation to what can be measurcd in<br />
laboratory testing, primitive. Important parameters are<br />
often collccted by untrained people as secondary task in<br />
lhe rescue work at lhe accident scene. The precision and<br />
accuracy of the data can therefore often be qucstioned<br />
and the possibilities to draw conclutions are often<br />
limited. By using modern technology, such as photogrammetric<br />
measurements of exterior and interior of the<br />
vehicle deformations, cheap crash pulse recorders (CPR),<br />
and by training workshop and rescue personal, the<br />
possibility to collect high quality accident data can be<br />
dramatically increased. In this prescntation, such a<br />
comprchensive system is described, in terms of potentials<br />
and possible output, as well as a theorctical background<br />
for increasing precision of collected datit.<br />
Background<br />
Real life accidents is the leading source for priorities<br />
in accident rescarch, legislation and vehicle construction.<br />
Methods used to gather and analyze information from<br />
accidcnts will thereforc bc of great importance. One field<br />
of certain intere$t is thc measurent of accident severity.<br />
There are mainly three fields where this is essential.<br />
A. Estimate of the accident severity distribution.<br />
B. Estimates of the relation between accident severity<br />
and injuries (risk, mechanism, severity, ctc.)<br />
C. Estimates of a protective measurc in a vehicle by a<br />
controlled study.<br />
Today, the accident severity is assessed by accident<br />
reconrrtruction or by indircct statistical methods (paired<br />
comparisons, (l)).<br />
Accidcnt reconstruction used for analysis of occupant<br />
protcction is always a result of a retrospcctive method.<br />
Accidcnt severity is assessed by measuring adequate<br />
pilrameters on the vehiclc in order to calculate the energy<br />
absorbed. The accident sevcrity is often given in change<br />
of velocity (aV), although this is sometimes relatcd to<br />
either burier velocity or energy equivalent or sometintes<br />
change of velocity during impact (2), (3).<br />
The data required for accident rcconstruction are<br />
different typcs of measurement on vehicles and<br />
sometimes from the accident spot. In mo$t cases some<br />
generalizcd constants are requircd. The precision of the<br />
assc$sment of acsidcnt severity is thercfore not otrly a<br />
matter of the methods used and the generalizations of<br />
constants in the models used, but also a matter of the<br />
measurelnents takcn from the vehicles involved.<br />
In accident research including accident reconstruction,<br />
there will always be enor tcrms also in the independent<br />
variables, that is the accident scvcrity. This is, howcver,<br />
overlookcd thus causing somc serious problems. In this<br />
pilper, the error in the accident scverity term is discussed<br />
in relation to sotne simple examples, and a modcl for<br />
morc advanced data collcction and methods is shown.<br />
Thc aim of the paper is to show how betlcr tttcthods can<br />
affect the results of future data collection. The aim of<br />
the paper is also to show how bctter methods can be<br />
cheapcr than otherwisc used methods.<br />
Accuracy of estimation<br />
In order to demonstralc lhc influence of measurement<br />
effors, a simple regression rnodel was used for a sirnple<br />
simulatcd data set where the relation betwccn accident<br />
severity and somc nlcasurement of injury or damage to<br />
the vehicle was studied. The modcl used is a simple<br />
linear model, but a log-linear or logit approach with a<br />
4l<br />
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13th lnternatlonal Technlcal Conterence on Expeilmental Satety vehlcles<br />
dichotomized dependent variable could have been studied<br />
instead, with the same conclusions possible to draw.<br />
In the simulated data set, the measurement variable<br />
was given an error of 0, 10, 20 and 307o standard<br />
deviation for each value of Y. Thc number of<br />
observations was 60, with ten cases for each Y. In table<br />
I the data set as a diagramme is given and in table 2 the<br />
outcome is shown. It can be seen that the rcgression<br />
coefficient is strongly affected and where the error was<br />
30Vo,the coefficient is reduced by more than 507o.It can<br />
also be seen that the standard deviation of the regression<br />
coefficient is increased to a large extent. In a more<br />
realistic data set, with more cases in low speed and less<br />
cases in high severity, the loss of precision would have<br />
even morc effects on thc parameter estimates.<br />
Table 1. Schematic rsletion between eccident $everity<br />
(X) and injury risk (Y) and a lineer equetion describing<br />
the relation<br />
90<br />
X<br />
,',1,<br />
.!,'<br />
,:/,<br />
,i<br />
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,,/,, .<br />
.:r'<br />
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Table 2. Regresslon coefflclents (a for <strong>Int</strong>ercept and b<br />
for slope) end emount of varlance explained (R'; by a<br />
slmple linear model Y = I + bX where X is sublect to<br />
measuremont orrors of 0, 10, 20 and 30c/o<br />
paremeter 0Vo enor l0% error ZOVo error 30% error<br />
&<br />
b<br />
t(b)<br />
R2<br />
15<br />
20<br />
2.23<br />
1.93<br />
65.7<br />
0.98<br />
25<br />
10.6<br />
t.67<br />
1r.5<br />
0.85<br />
30<br />
35<br />
26.3<br />
t.l9<br />
9.5<br />
0.61<br />
,7<br />
40<br />
45<br />
38.8<br />
0.81<br />
6.4<br />
0.41<br />
50<br />
The phenomenon presented in table 2 is well known<br />
from the shtisticirl litterature and the chanue of the<br />
regression coefficient is sometimes given as<br />
42<br />
a= B where<br />
(l+E)<br />
E=<br />
J"t<br />
Jrt<br />
that is, the regression coefficient and the calculated<br />
relationship is affccted by thc measurcmcnt crror.<br />
The possibility to draw conclusions is also affcctcd as<br />
the relation between what can be detected and the<br />
meflsurement error is highly affected.<br />
An another related problem is misclassification of<br />
variables. In the following example, the belt use among<br />
ciu occupants is misclassified to different amount. In<br />
table 3, the -'true" data is given with the estimated belt<br />
effectiveness of 507o given by thc formula;<br />
Effect = I - r(b) | r(u) , where<br />
r(b) and r(u) are the estimated risk of injury for belted<br />
and unbelted occupants respectively.<br />
Table 3. calculated belt effectiveness wlth different<br />
emount of misclassification<br />
Level of misclassification Belt effectiveness<br />
OVo<br />
LOVo<br />
20%<br />
30%<br />
50%<br />
42%<br />
33Vo<br />
24Vo<br />
It can be sccn in table 3, that a random misclassification<br />
of 30Vo leads to a calculatcd bcll cffectivcncss<br />
that is reduced hy more than 507o. Already a misclassification<br />
lcvcl of l07o is of great importance. This has got<br />
two important implications. Firstly, the estimation of the<br />
effectiveness is reduced cvcn whcn the samplc size<br />
increases and secondly, the numbcr of observations that<br />
must be collected to show that thc scat bclt is cffcctive<br />
at all must be increased.<br />
Advanced accident data collection<br />
The elements of advanced data collection is to<br />
increase the accuracy of the collcctcd dflta dramatically<br />
in order to producc bcttcr cstimates and with fcwer<br />
observations. There are mainly three areas whcre this is<br />
described; estimation of crash severity, measurement of<br />
vehicle deformation and assessment of injuries including<br />
use of restraints and contact areas.<br />
Photogrammetrical measurement<br />
In order to measure exterior and interior vehicle<br />
deformations with high accuracy and minimize the<br />
systematic error, a photogrammetrical measurement<br />
system was developed (a).<br />
:'<br />
:
Ttre photogrammetricat system is based on specially<br />
adapted small format cameras and a special software for<br />
threedimens ional measurements.<br />
Using the special camera a standard set of 24<br />
photographs are taken covering both the exterior and the<br />
interior of the car, Before taking thc photographs, the car<br />
is prepared with scaling rods on the roof and some<br />
adhesive stickers. The fieldwork is normally done in less<br />
than 15 minutes.<br />
Data processing is done in a centralized workshop<br />
whcrc a small group of people evaluate the measurements.<br />
The photos of importance are mounted on a<br />
digitizing tablet connected to a standard personal<br />
computer and the points of interest are measured and<br />
their threedimensional coordinates are calculated. The<br />
work station is seen in fig l.<br />
Flgure L Worlrstation for the Photogrammeticel Syetem<br />
informations on occupants<br />
questl()nalres<br />
diagnoses of injuries<br />
Advanced data collection<br />
observation on accident spot<br />
ambulance (police<br />
Sectlon 3: Technlcal Sess/ons<br />
A set of standard points are available for the car<br />
models measured. These previously known undefornted<br />
points are uscd to orient the measuremcnts into a specific<br />
coordinatc system. These points are also used for<br />
deformation vector calculation.<br />
The measurements are presented as deformation<br />
vectors for standard points. AII other meflsurements flre<br />
presented coordinates in the car specific coordinate<br />
systcm. The output is shown in fig 2.<br />
The accuracy in the system in cvery single pair of<br />
photographs is approx 5 mm and after transformations<br />
the global accuracy is better than l5 mm in space.<br />
CPR - Crash Pulse Recorder<br />
The measurement of the crash scvcrity is made by an<br />
in vchiclc recorder with the main purpose of making aV<br />
estimations of impacts (5). It is a very simplc one<br />
dimensional accelerometer which can register the<br />
accclcration time history, though with a lower precision<br />
and a lower sampling frequency than an accelerometer<br />
for laboratory usc.<br />
Thc CPR, fig 3 is based on a spring mass system<br />
where the displacement of the mass in an impact is<br />
measured. The registration of the displacements of the<br />
mass is donc on a photographic film by light emitting<br />
diods (LED) driven by a crystal oscillator circuit with a<br />
frequency of 1000 Hz. The circuit has its own power<br />
supply. The circuit is activated by a micro switch when<br />
the mass starts to move in a crash.<br />
crash recorders (CPR)<br />
ACCIDENT photogrammetric<br />
rllcasurements<br />
interior inspection<br />
with video canleras<br />
contact points<br />
evidence of restraint use<br />
AV<br />
rnean acceleration<br />
tirle duration<br />
deformations<br />
exterior and interior<br />
Y Z disnlacements<br />
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lSth lnternatlonal Technical Conterence on Experlmental Safety Vehlcles<br />
After an impact the registrations on the photographic<br />
film, fig 4, is measured and the CPR is calibrated to get<br />
adcquate parameters measured. The accuracy of the CPR<br />
is mostly linked to production quality and quality of the<br />
mcasurement equipment for the photographic film. The<br />
overall accuracy of aV estimations will be better than<br />
SVo,<br />
4. IilEASUREMENTS EXTEBIOR POINTS<br />
8. MEASI,JE:MENTS STAUC;UHE AND SFE':AL<br />
Figure 2. Output lrom the Photogremmetical<br />
llJleasurement System<br />
<strong>Int</strong>erior inspection<br />
In order to get a more objective picture of the interior<br />
of the vehicle, the interior inspection should be done<br />
after all other information has been gathered and by an<br />
expert team. This can be done by using a videocamera<br />
and whcrc the film is analyzcd afterwards togcther wilh<br />
measurements of deformation and accident severitv.<br />
ht<br />
Flsure s cP;<br />
"*<br />
Observations on the accident spot can be picked up by<br />
interviewing the ambulance team.<br />
Discussion<br />
In this paper the measufement error in the redonstruction<br />
of real life accidents is addressed. This is an area<br />
where most studies related to the relation between a<br />
measurement variable and an outcome resulting from this<br />
parameter does not take any error into account.<br />
In this pflper, some simplificd cxamples of measurement<br />
errors arc shown together with the eff'ects on the<br />
outcomc of estimates. Even fairly small errors leads to<br />
estimates that are significantly affected, normally<br />
reduced. This means thflt protective measures can be<br />
overlooked even if they are effective and even if a large<br />
sample of accidents is used (6). In cases where there are<br />
measurement errors the number of observations will not<br />
eliminate the influcncc. This is an cxtremely important<br />
fact, well known in statistical analysis but more or less<br />
forgotten in quantitative accident research. lt is easily<br />
realized, that there are plenty of results from studies that<br />
are heavily biasecl and relationships bctwccn variablcs<br />
that arc wrongly statcd to bc wcak. It is bclicved that<br />
especially the relation between accident severity and<br />
injury risk is biased<br />
The reliability of the data is not the only important<br />
issue in accident reconstruction. Also the validity must<br />
be addrcssed. In this papcr, ways to measurc also other<br />
parameters than just deformation of vehicles is<br />
dcscribed. The possibilities to measure with more<br />
advanced methods will lead to questions raised about<br />
what are the most adequate parameters to use in<br />
reconstruction.<br />
The rcliability of assessmcnt of change of velocity is<br />
hases on several parameters when using reconstructive<br />
f f i w ] tlw<br />
Figure 4. Dlsplacement heglstration of the CPR on a Photographic Film<br />
44<br />
J,.,,t,,<br />
t., l,t/s) - ys<br />
-\+-
methods. In a study of the CRASH-3 method, the mean<br />
error was 13.8-17.8 7o but the objects studied were fairly<br />
simplc. In other materials the error may well be larger,<br />
also including possible systematic elrors.<br />
The term advanced data collection is addressed to an<br />
approach where the measurement crrors are minimized to<br />
a level where they do not lead to interference with<br />
estimates and where the number of observed accidcnts is<br />
minimized. Instead of studying a large population, a<br />
subset of vehicles are studied in more detail. If these<br />
vehicles are prepared with on-board measurement<br />
devices. and if the crashed vehicles are all studied with<br />
advanced technique, a population of approx l0 000<br />
vehicles will produce a number of accidents in one year<br />
that will give a high precision in i.e., injury risk for<br />
occupants.<br />
An on boiud recorder can give a level of precision that<br />
can be used for advanced data collection if it is simple<br />
and cheap. In this paper such a recordcr is presented.<br />
The describcd rccorder can be used for frontal collisions<br />
and givc a good estimate of thc change of velocity as<br />
well as the time and mean deceleration, without using<br />
measurements of the static deformation of the vehicle.<br />
This is of great importancc, as the the deformations of<br />
the car will be a function of the change of velocity and<br />
not vice versa as it is in reconstruction using<br />
deformation measurements. Still, deformations of the<br />
vehicle outside and insidc is of interest,and a method for<br />
increasing mcasurcnt reliability is prescnted. In this<br />
technique, using photogrammctry, the measurements ciln<br />
be done afterwards and by cxperts thus minimizing both<br />
systematical, random and intraobserver elrors. In a study<br />
of the reliability of cxterior measurements, thc crror was<br />
at least 5 times larger than when using photogrammetry.<br />
In the data collection used today, most vchicle data is<br />
gathered by individual members of a team, and at one<br />
momcnt. In the technique presented in this paper, the<br />
data consists of materials not possible to destroy by<br />
incorrect judgement by the data collectors. Instcad, the<br />
data collection and the data proccssing is separated and<br />
where it is an important part of thc concept to use<br />
sr.o.03<br />
Data Linkages in Real Crash Analysis:<br />
A Key to Progress in Road Safety<br />
Urs Maagr<br />
Denise Desjardins<br />
Claire Laberge-Nadeau<br />
Universite de Montreal<br />
Abstract<br />
Govcrnmcnt agencies and insurance companics collect<br />
and record on computer files enormous ilmounts of data<br />
lUntil<br />
th. end of May 1992, <strong>Section</strong> de mathdrnatiques, Univetsiti de Gen6ve.<br />
<strong>Section</strong> 3: Technical Sessions<br />
experts when processing the data collected. Restraint use<br />
judged by using several sources such as interior vehicle<br />
inspection (belt tongue andjoints, anchourages, webbing<br />
etc.), interview with occupants and ambulance teams.<br />
In the future, fast and precise statements of the<br />
performance of new safety systems and constructions are<br />
strongly necded. The methods used today cannot serve<br />
this purpose sufficiently and a change in the scicntific<br />
methods is essential. It thercfore seems to be more<br />
realistic lo use small populations of vehicles studicd<br />
where the fleet has been prcpared and where an<br />
organization that can minimize errors is developed.<br />
References<br />
I. Gustafsson H, Hiigg A, Krafft M, Kullgren A,<br />
Malm$tedt B, Nygren A, Tingvall C, Folksam Car<br />
Model Safety Rating 1989-90.<br />
2. F Hartemann, J Y Foret-Bruno, C Henry, G<br />
Favcrjon, C Got, A Patel, J C Coltat, Thc<br />
charactcristics of frontal impacts in real world<br />
accidents, ln: proceedings of the <strong>ESV</strong>-confercnce<br />
1987;42a-4r.<br />
3. D Otte, Comparison and realism of crash simulation<br />
tests and real accident situations for the<br />
biornechanical movcmcnts in car collisions,<br />
Proceedings of the STAPP car cra$h conference,<br />
902329, 1990.<br />
4. Lie A, Tingvall C, Johansson S, Johansson S-O,<br />
Photogrammetric measurements of damagcd vchicles<br />
in road traffic accidents, In: proceedings of the <strong>ESV</strong><br />
confcrence 1989.<br />
5. Aldman B, Kullgren A, Lie A, Tingvall C, Folksam<br />
Research and Chalmers University of Technology,<br />
Dep of injury prevention. Crash Pulse Recordcr<br />
(CPR) - Devclopment and evaluation of a cheap<br />
device for measuring crash pulse and delta-V in real<br />
lifc accidents, Accepted for publication in the<br />
procccdings of the <strong>ESV</strong> confcrence 1991.<br />
6. Malliaris A C, Digges K, Crash protection oflered<br />
by safety belts. In: proceedings ot the <strong>ESV</strong><br />
conference 1987 : 242-252.<br />
on road accidents. The collection of this data serves<br />
mainly for administrative purposes and only occasionally<br />
for research. The objectivc of lhis paper is to arguc and<br />
to show that useful research projects can be carried out<br />
relativcly cheaply, using basically administrative data, if<br />
linkage of files and linkage with other sourccs i$<br />
possible.<br />
In Qucbcc where there is compulsory Bovernment car<br />
insurance, except frlr material damagcs, there is a<br />
45
13th lnternatlonal Technlcal <strong>Conf</strong>erence on Experlmentel Safety Vehtctes<br />
particularly favourable situation making possible the<br />
creation of complete and rich databases organized by<br />
individual records. This article shows the research<br />
potential of such databases on the example of two<br />
studies, one on the effects of age and experience in<br />
accidents with injuries, the second on medical conditions<br />
and drivers' records. It is also pointed out that the<br />
researchers have to assume a great responsibility in order<br />
that the privacy of individuals is maintained very strictly,<br />
i.e. data about an individual must be kept confidential,<br />
and the files should not carry any identity of individuals,<br />
only numbers.<br />
fntroduction<br />
Sincc accidents are relatively rare events, usually<br />
between 5 and 107o of permit holders are involvcd in an<br />
accident in any given year, large databases are needed to<br />
study trends, associations between variables, rates for<br />
subgroups, etc. Furthermore such data sets should be<br />
availablc by individual and not just in an aggregate form;<br />
they should contain also the history of driving records.<br />
Researchers often would like to be able to gathcr the<br />
data for their projects themselves to make sure thal the<br />
right variables for an appropriate sample of the population<br />
are available. We know that in most cases this is<br />
only a dream since thc cost and the time necessary ro<br />
acquire such a set of observations are far in excess of the<br />
availablc grant moncy. What are the alternatives? A lot<br />
of information is present in government agencies, police<br />
reports and insurance companies. In the case of a state<br />
insurance much of this information may even be<br />
centralized. The initial problem is how to obtain, verify<br />
and collate the information held by different agencies. A<br />
second problem is how to enrich the available information<br />
in order to answer a given research question.<br />
It will be shown that the situation in Quebec is<br />
particularly advantageous for research using govcrnmcnt<br />
files, possibly enriched by survey data. The use of such<br />
a database must be foundcd on a mutual trust between<br />
the government agency and research teams. Two reccnt<br />
examples will serve to illustrate the tremendous<br />
possibilities available to do projects for reasonable<br />
amounts of money. The importance of a strict ethical<br />
conduct by the reseatchers, their assistants, students and<br />
technical collaborators is also discussed.<br />
The Quebec Situation<br />
Statc insurance against car accidents exists in Quehec<br />
since the fall of 1978. Material damages to cars and<br />
property are excluded because they are covered by<br />
private insurance. The state insurance is now administered<br />
by the Societe d'assurance automobilc du Quebec<br />
(SAAQ), previously known as the Regie d'assurance<br />
automotrile du Quebec (RAAQ). Over the years, the<br />
SAAQ was given the responsibility of gathering and<br />
administering the official data in the Province of Quebec<br />
on driving permits, car rcgistrations, dernerit points,<br />
46<br />
infractions, suspensions, police accident reports,<br />
insurance claims, medical reports pertaining to such<br />
claims and corresponding payments. Almost all the data<br />
is on computer files which the SAAQ uses for its annual<br />
reports and for projects carried out by its intcrnal<br />
research group. Parts of these files are available to<br />
researchers in anonymized form. The quality of the data<br />
is generally as good as the original source as shown<br />
through verifications carried out by members of our<br />
team. Data about payments will be most trustworthy<br />
becausc accounts get audited. Since all thesc filcs are<br />
controlled by the same agency, it is relatively easy to<br />
link them and to create sub files containing specific<br />
variables and subgroups of the population. Thus a very<br />
large and rich database is available for rescarch. To<br />
exploit even parts of the base, a rcscarch team needs a<br />
powerful computer and a knowledgeable analyst.<br />
The data are of course not public. Access is only<br />
granted for specific projects and to peoplc that meet wirh<br />
the approval of thc SAAQ. Only relevant variables are<br />
released and idcntifiers are always removed.<br />
A further and oftcn necessary step is the addition of<br />
data either obtained through a survey or from another<br />
source such as an insurance company (matcrial<br />
damages). In such cases thc mcrger of the SAAQ file<br />
with the outside file is done by the agcncy who holds the<br />
key to thc idcntificrs for the files which are deleted<br />
before the merged file is made available.<br />
Two Examples<br />
The effects rtf aye and experience on accidents with<br />
injuries<br />
This study is hased entirely on the filcs of the SAAQ.<br />
It was made possible by some special computations done<br />
for our tcan by the agency. The two areas lookcd at<br />
wcrc: a) rrge at first licensing, and b) accident ratcs as a<br />
function of agc and cxpcricnce.<br />
The minimal legal age to obtain a driving permit is l6<br />
ycars which is lower thln in most European countrics<br />
where it is l8 years. Over the pcriod from l97I to I985,<br />
the acquisition of driving permits by 16 year old has<br />
increirsed steadily form 6Vo to 42Vo for men and from 27o<br />
to 21Eo for women. By age 18, about 75Vo oI the men<br />
havc a driving permit. The attributcs "lack of<br />
cxpcrience" and "young" are thus confounded when<br />
looking at global accident statistics.<br />
Thc scconcl part of the study attempts to shed some<br />
light on thc scparalc cffects of age and of experience.<br />
Each drivcr involvcd in a car crash resulting in injurics<br />
was categorizcd by sex, age and by driving expericncc.<br />
The age variable was grouped by yeius from 16 to 24,<br />
then the groups 25-34, 35-44, and 45 or more. The<br />
experience variable was dichotomizcd into "one year or<br />
less" and "morc than one year." Young drivcrs, i.e.<br />
below 25 yeflrs, were the principal target group. No<br />
exposure variahle was available. which must be taken<br />
into account when interpreting the results. For example,
young women drive on the average far less than young<br />
men. There are large variations in risk exposure between<br />
the young person who occasionally drives the family car<br />
and the person who uses an automobile to drive regularly<br />
to and from work.<br />
Here are the main results: a) Accident rates for women<br />
are yery much smallcr than those for men; b) From age<br />
16 to 24, accident rates decrease approximately linearly<br />
with age (for men and women); c) There is hardly any<br />
difference betwecn experienced (morc than one year) and<br />
new drivers. This means that a driver who acquired a<br />
permit at age 16 is not a better driver, in terms of<br />
averagc accident rates, at age 2l than the one who<br />
acquircd the permit at age 19 or 20. Howevcr, thc young<br />
16 year old liccnsee has a good chance of being involvcd<br />
in an accident during those five years (see Bourbeau et<br />
al., l99l).<br />
The question which thus confronts the population in<br />
general, and the politicians in particular, is: Should the<br />
licensing age be raised in Quebec from 16 to 18, the<br />
minimal agc required in most European countries?<br />
Medital conditions and drivers' records<br />
The SAAQ requested a comparative study (permit<br />
holders with a medical condition vcrsus healthy ones) of<br />
the effccts of certain medical and ophthalmological<br />
conditions on road safety in terms of accidcnt rates,<br />
demerit points and suspensions, taking into account the<br />
distanccs driven. Special restrictions, based on safcty<br />
considerations, apply to drivers of trucks, busses, taxis<br />
and even automobiles in the case of elderly drivers. In<br />
order to acquire exposure variables, a survey had to be<br />
carried out. A questionnaire appropriatc for a telephone<br />
survey was constructed and virlidated, since this was the<br />
only way to obtain a sufficicntly large sample at a vcry<br />
reasonable cost.<br />
In this instance, the interaction between the SAAQ and<br />
the research team bccame quite considerable. Using the<br />
computerized files, thc team was allowed to obtain the<br />
basic statistics on the drivers in a given permit class<br />
having a certain medical condition (the cases) and the<br />
ones being in good health (the controls). As a consequcncc,<br />
some groups of drivcrs had to be left aside since<br />
they contained too few individuals, for example female<br />
permit holders in the classes I to 4 (trucks, busses and<br />
taxis), and truck drivers above age 65.<br />
The telcphone $urvey based on our questionnaire was<br />
carried out towards the end of 1990 by a polling<br />
company attempting to reach 17 658 individuals. The<br />
response rate was 64.SVo, evcn 7SVo when corrected for<br />
invalid telephone numbers. The file resulting from the<br />
survey was linked with the SAAQ file that contains the<br />
safety and basic medical rccords of the drivers, resulting<br />
in a large anonymized database ready for analysis. The<br />
first results have been prcsented this summer at various<br />
conferences: Joly et al. (l99la), Joly et al. (l99lb),<br />
Desjardins ct al. (1991), Maag et. al. (1991). Many more<br />
<strong>Section</strong> 3: Technical Sessions<br />
analyses of this very rich data set are being carried out<br />
and are planned.<br />
File Linkage and Ethical Considerations<br />
For the researcher it is advantageous to have as free<br />
an acccss as possible to thc files. It is fllso important to<br />
be ablc to link various files and to add variables from<br />
other sources such as a survey or a file belonging to<br />
another agency or a company. A researcher likes to be<br />
able to create appropriatc sub files, fetch an additional<br />
variable when nccessary, do crosschecks, and so on.<br />
There arc also advantages for the owner of thc files:<br />
More information can be obtained from the files by<br />
commissioning analyses or letting a researcher carry out<br />
a projcct without the owner having to hirc additional<br />
staff. Thus, sharing files is good economics.<br />
Thc owner of the filc, however, is obligcd to keep the<br />
data on individuals protected. This is particularly true for<br />
government agencies. There are legal restrictions, and<br />
penalties for people who divulge data on individuals.<br />
Consequently, it is not surprising that agcncies are<br />
hesitant about granting acccss to their files. Private<br />
companies are worried in addition about data talling into<br />
the hands of their c:ompetitors. Howevcr, there are states<br />
in the U.S.A. Ihat give the possibility of linking data for<br />
rescarch purposes by law or by introducing a special bill,<br />
particularly for cpidcmiological research.<br />
In our view, thcsc two opposing positions can be<br />
ovcrcome by mutual trust and by an cxcmplary ethical<br />
conduct on the part of the researchers. In any way,<br />
mutual trust does not happcn overnight, it has to be built<br />
up gradually. Researchcrs have to show competency<br />
through the production of useful results and new<br />
insights. Researchers must never reveal any individull<br />
data, and furthcrntore it is their duty to make sure that<br />
their assistants, students and tcchnical collaborators live<br />
by the same principlcs. They also must take the<br />
necessary stcps so that no unauthorized third party can<br />
gain acccss to the data. Today's open computer systcms<br />
and nctwork facilities dcmand extra care to protect files.<br />
A company or government agency can crect fairly<br />
stringent safcguards, but at considerable cost. For<br />
example the dnta analyst may have to work in the<br />
agency's offices and on its computcr. If trust and<br />
responsibility are present, a lot can be gained.<br />
Conclusions<br />
Large databases that are pertinent and essential to<br />
research in traffic safety exist in governmcnt agencies,<br />
insurance companics and hospitals. Good research can be<br />
accomplishcd iI access to these data is permitted, it the<br />
quality of the filcs can be verificd, if different data sets<br />
can be linked, and if additional information, for example<br />
from surveys, can be added in ordcr to construct a<br />
complete database organized by individual records.<br />
Indeed, large bases that are neccssary to exanrinc<br />
accidcnts (rare events) on a statistical basis can seldom<br />
47
13th lnternatlonal Technlcal conference on Experlmental safety vehlcles<br />
be gathered for a reasonable price by individual<br />
researchers.<br />
Such access can work under two premisses: On the<br />
one hand, an open mind and a willingness to cooperate<br />
is necessary on the part of the owners of the files, and<br />
on the other hand exemplary ethical conduct by the<br />
researchers and their teams is mandatory. Cooperation to<br />
enable linkage of files from different sources is thus a<br />
key to progress in road safety.<br />
References<br />
Bourbeau, R., Laberge-Nadeau, C., Maag. U. (1991),<br />
"The<br />
Effects of Age and Experience on Accidents with<br />
Injuries: Should the Licensing Age be Raised?," Accident<br />
Analysis and Preventions 24 (6), to appear.<br />
Desjardins, D., Ekoc, J.-M., Ghadirian, P., Hamet, P.,<br />
Laberge-Nadeau, C, Maag, U. (1991), "Dcmarche<br />
methodologique pour evaluer I'impact de trots conditions<br />
medicales sur la securitc routiere en fonction de<br />
differentes categories de permis de conduire," Compte<br />
rendu de Canadian Multidisciplinary Rttad Saftty<br />
st.o.04<br />
Child Casualtiesln Fatal Car Crashes<br />
Harold Vallee, Marie Christine Caillieret,<br />
Gerard Faverjon, Jean Yves Le Coz,<br />
Jean Marie Heinrich, Christian Thomas<br />
Accident Research and Biomechanics<br />
Laboratory Associated with Peugeot<br />
S.A./Renault<br />
Jean Claude Coltat<br />
Poissy <strong>Int</strong>ercommunal Hospital Centre<br />
Claude Got<br />
Institute of Biomechanics and Accident<br />
Research<br />
Alain Patel<br />
Orthopaedic Research Institute<br />
Abstract<br />
The circumstances in which children aged less than i0<br />
travelling in passenger cars are severely injured or killed<br />
are different from the circumstances in the case of<br />
adults.<br />
Our knowledge in this field of safety is very limited<br />
at pre$ent, becausc it is hflrd to collect a large sample of<br />
severe accidents involving children.<br />
On thc basis of police reports on fatal crashes<br />
occurring in France in 1990, concerning 417 casualties<br />
aged less than 10, one quarter of whom were killed, we<br />
propose defining the characteristics of such crashes by<br />
analyzing the following paramctcrs:<br />
<strong>Conf</strong>erence VII, 381-392, Vancouver, Canada, June<br />
r7 -r9.<br />
Joly, P., Gagnon, R., Trudel, G., Joly, M.-F., Desjardins,<br />
D., Maag. U., Messier, S., Labcrgc-Nadeau, C. (1991a),<br />
-'L'exposition<br />
au risque dc conduire un vehicule routier<br />
chez les personnes agees en fonction tea normes<br />
visuclles minimales," Compte rendu de la 6e <strong>Conf</strong>erence<br />
sur les comportements de deplacemenrs", Qucbec,<br />
Canada, tome 2, 135-149, May 22-24.<br />
Joly, P., Joly, M.-F., Desjardins, D., Messier, S., Maag.<br />
U., Ghadirian, P., Laberge-Nadeau, C. (1991 b),<br />
"Exposure<br />
for Dillcrcnt License Categories through a<br />
Phonc Survey," 35th Annual Proceedings of the Association<br />
for the Advancement of Automotive Mededne,<br />
Toronto, Canada. Novcmber 4-7.<br />
MaaB. U., Desjardins, D., Joly, P., Laberge-Nadeau, C.<br />
(1991), "How to Define, Estimate, and Compare<br />
Accident Ratcs for Slrata of Drivers," Compte rendu de<br />
Canadian Multidisciplinary Road Safety <strong>Conf</strong>erence VII,<br />
?84-292, Vancouver, Canada. June 17-19.<br />
1. Child transportation conditions;<br />
2. Crashcircumstances:<br />
3. Restraining systcms.<br />
Materials and Methods<br />
The samplc used consists of 275 fatal motorist crashes<br />
(the policc rcports for which were kindly made available<br />
to us by the police l'orccs) in which at least onc child<br />
aged less than l0 is involved. All the crashes analyzed<br />
occurred between lhc beginning of March 1990 and the<br />
end of Fehruary 1991.' Each of these reports contains<br />
the following informalion: a detailed drawing of the<br />
crash, a series of photographs (locations, vchicles<br />
involved), a brief (wear lcvcl of tyres, etc.). Thc rcport<br />
also includes: the statements of those involved and thc<br />
witnesses, the medical state of the injurcd (only the<br />
location and nature of the injuries sustained by the<br />
dcceased are unknown, for want of an autopsy) and,<br />
finally, the result of the driver alcohol tests whcn it is<br />
known.<br />
The conditions requircd to judge as to whethcr or not<br />
rcstraining systems werc used are as follows: observation<br />
of the system's presence in the vehicle by thc police<br />
forces, confirmed by the statements of thosc involved<br />
and witnesses. We later contactcd the family of the<br />
rcstrained children individually, via a qucstionnaire and<br />
even by telephone whenever necessary.<br />
The criteria set by us for characterizing impact<br />
mechanisms and their injury consequences are as<br />
follows.<br />
lTo enable chronological comparisons we use a sample of polie rtports on fatal crashes occurdng in the 2nd querter of 1980 on the whole national network.<br />
48
. The intrusion evaluated on photographic documents<br />
is quantified by the percentage of reduction of the<br />
free spacc in front of, behind, or to the right or left<br />
of each child. Thus, in frontal impact, intrusion is<br />
considered to occur when the reduction of available<br />
space is at least equal to 30Vo f.or a child seated in<br />
the front. For a child in thc back seat, only those<br />
cases in which the windscreen pillar intruded as far<br />
as the centre pillar were considered as intrusion<br />
mechanisms. ln side impact, the intrusion thresholds<br />
taken into account are as follows:<br />
- for a near-side occupant, whenever the external<br />
deformation of the side panel suggests a direct<br />
intrusion on the occupant;<br />
- for a far-side occupant, whencver the vehicle<br />
deformation has affectcd the car body axis. ln<br />
rollover, intrusion is considered to occur when the<br />
roof panel penetrates close to the window baseline.<br />
. Projection concerns all unejected children who are<br />
not victims of intrusion.<br />
It was not possible to use the criteria that we normally<br />
adopt for technical analysis of vehiclcs, namely, the<br />
delta-V and mean acceleration. Of thc 157 frontal<br />
impacts observed, I l5 EES's were estimated and only 63<br />
delta-Vs are calculated. Since the deformation<br />
mca$ursments of the vchicles are not known, the<br />
acceleration is not calculated.<br />
Child Transportation Conditions<br />
Vehicle Otrupancy. Thc average global occupancy rate<br />
(children and adults) of the vehicles involved in fatal<br />
crashes and having (at least) one child on board has<br />
varied little over thc last ten years: it was 4 occupants in<br />
1980 tll, and 3.7 in 1990. The same applies for the<br />
average number of children per car: 1.6 in 1980 and 1.5<br />
in 1990. There has, however, been a sharp declinc in the<br />
rate of car over-occupancy: lZVa oI cars contained 6<br />
occupants or morc in 1980, as against<br />
'7V, in l9.L)0<br />
[Figure l].<br />
Number of<br />
vchicles<br />
60<br />
l*lspt61 6f mcupmts (children md adule)<br />
Flgure 1. Occupation (adult$ or children) of the 275 Cars<br />
with a Child at Lsest<br />
Sectlon 3: Technica/ $esslons<br />
The situation most frequently encountered (60% of<br />
cases) is the prescnce of a single child in the vehicle.<br />
Thc prcscncc of two adults in the vchicle with child(ren)<br />
is observed in 43 Vo of cases [Table 1]. Thc most<br />
frequent (children/adults) combination is I child and 2<br />
adults, or close on a quarter of cars with a child.<br />
Table 1. Occupancy (adults and children) of the 275<br />
vehiclee with children on board<br />
Nnrrbrr<br />
of adults<br />
TOTAL<br />
(vehicles)<br />
I<br />
umbcr of children<br />
l l l l r o r A l<br />
tltlolul<br />
tvehicleE)<br />
2 I 70<br />
63 39 15 r18<br />
36 4 I 56<br />
18 J I 1a<br />
6<br />
Although the presence of a child aged less than 10 in<br />
the front scat is prohibited in France, 12 children were<br />
seated thcre. Of those, 7 were agcd less than 5 and 2<br />
were seated on the knees of an adult.<br />
Of the 390 children sitting in the rear, only the<br />
positions occupied by 230 children were determincd<br />
prccisely. The outer positions seem to be used unequally.<br />
Only the central rear position is seldom occupicd: I 137o<br />
of the children werc scated there [Table ?].<br />
Table 2. Positions Occupied by the Children According<br />
to Age<br />
Position of child<br />
Restraining Sy.srems Used. Only l4Vo of the children<br />
were wearing a restraining system. No car bcd dcsigned<br />
according to the regulittions for infants aged l-9 nlonths<br />
was used, whilc l4 very young childrcn werc transported<br />
in a cot. In the refercnce sample, one observes that 6<br />
child restraining systems out of l0 arc uscd by children<br />
aged less than 2. As for booster, they are seldom used:<br />
I<br />
7# 82 23 2 2 tl5<br />
ACE OF CTIILD<br />
srlz la lr ls le lz la lr TOTAL<br />
Iiront I 2 3 I J 12<br />
Left 22 6 10 4 7 72 E 13 E 90<br />
Rear Ccn{re t? 5 3 4 4 4 z 2 5 42<br />
Position<br />
unspecified<br />
Position<br />
undcriemined<br />
(front or rear)<br />
Right 28 7 r0 9 13 6 I r0 o 98<br />
l9 17 24 l9 77 l9 20 il I4 160<br />
I 0 c 7 I 5 0 l5<br />
TOTAL 84 36 54 4l A2 45 4l 38 36 477<br />
1<br />
49
lSth lnternatlonal Technlcal <strong>Conf</strong>erence on Experlmental Satety Vehlcles<br />
4 cases [Figure 2]. The use of child seats and booster is<br />
in many cases in compliance with the stipulations for use<br />
laid down by the French regulation of 1985 (weight of<br />
the child). Only two children among the 15 users of<br />
child seats-whose weight and size are known-had a<br />
weight slightly less than the recommended weight. The<br />
general trend, however, is that most restrained children<br />
have a weight close to the minimum weight threshold<br />
required for the systcm used by them [Figure 3]. 19 of<br />
the 60 children aged less than 10 used exclusively the<br />
seat belt designed for adults.<br />
A6E 6<br />
7<br />
I<br />
BELT FEIruNT<br />
Figure 2. Type ol R8streint Used According to Age of<br />
Ghild (N=60)<br />
o s r o r r z o 2 5 i o 4 3 6 0<br />
wcirht (lE)<br />
Figure 3. Size and Weight Di$tribution of Children<br />
According to the Specific Restraining System Used<br />
50<br />
ri0<br />
140<br />
130<br />
120<br />
l lo<br />
tm<br />
80<br />
lo<br />
t-<br />
I<br />
II I<br />
i_<br />
i<br />
r.l____ _<br />
I<br />
t_<br />
I<br />
We specify that the rate of use of child restraining<br />
systems is, in France, among the lowest of those<br />
observed at the EEC level: 897o in 1989 in Sweden [2];<br />
from 50 to 60Eo in 1988 in West Germany [3]:25Vo in<br />
1987 in the United Kingdom [41.<br />
I'rip <strong>Conf</strong>igurations. Short trips (less than 30 km)<br />
reprcsent 4OVo of all lrips travelled by children.<br />
The lcngth of the Fips does not vary with the age of<br />
the childrcn [Table 3]. They are often the very reason for<br />
short trips (creche, school). They accompany their<br />
parents on the longest trips (week-ends, holidays).<br />
Table 3. Length of Trip Accordlng to the Age of the Child<br />
Length of<br />
trip (km)<br />
AGE QF CHILD<br />
-*tl , I , I o I r l u I r I e I o TOTAL<br />
-{ 30 23 l1 l4 L2 t0 13 12 t6 7 ll8<br />
JI 100 10 7 9 6 7 A 6 62<br />
r01 - 500 rrt t2 10 5 l0 l l0 1 81<br />
501 - 1000 5 2 3 2 z 2 3 3 26<br />
> 1000 I I 2 I 2 I<br />
Unknown 21 11 r5 10 17 1l r5 3 r3 t22<br />
TOTAL 84 36 54 4t 42 45 4t 38 JO 4rl<br />
There is no relation in the sample analyzed bctween<br />
the length of the trip and the frequency of use of a<br />
restraining system by the childrcn. It might have been<br />
thought that the risk as perceived by the pftrents would<br />
result in a highcr ratc of use of such systems on long<br />
trips, whereas it is the conlrary that is observed: 2I % ef<br />
the children making short trips were restrained, as<br />
against only l3Vo of child casualties on trips longer than<br />
100 km [Table 4].<br />
Table 4. Length of Trlp and Use ol a RestraininE System<br />
RESTHAINING SYSTEM USED<br />
I*ngth of tip cniu I bmstet I z-point I r- point I un- | unrnom I rmll<br />
seat | | sut belt I senr belr I restinined I I<br />
Table 5. Type of Hoad snd Global Severlty for Chlldren<br />
Type of road<br />
CLOBAL INJURY SEVERITY<br />
Fauliriesl severe<br />
I<br />
LiBhr<br />
I<br />
un-<br />
| severity TOTAL<br />
I inirrrier I inirrricr I hermed I unknown<br />
Motoruay r'1 9 t4 4l<br />
Freway I<br />
National hi8hway 4l 36 66 25 2 t70<br />
lJcpffimenlal rcad 35 34 90 ?0 2 rEl<br />
(iommunal lilc 5 6 I l5<br />
Oif public network 3<br />
Unknown 4 I 6<br />
TOTAL 103 84 49 5 417<br />
Almost half of the children (4'1Vo) arc involved in<br />
accidents on Saturday and Sunday. 48?a of crashcs occur<br />
between 2 p.m. and 8 p.m.<br />
Risk Factors. In car-to-car collisions, the presumed<br />
responsibility of the driver of the vehicle in which the<br />
child (or children) were travelling is observed in one<br />
third of collisions. The frequency of positive alcohol<br />
levels above the legal ratc of 0.tt0 g/litre of blood is<br />
close on four times higher for drivers without a child<br />
compared to drivers with a child (or children): ?7Vo and<br />
'lVo<br />
respectively in car-to-car collisions. All the<br />
differences observed with rcspect to both responsibility<br />
and alcohol level are statistically significant. Finally, we<br />
may add that 867o of the children were being driven by<br />
their parents.<br />
Crash Circumstances<br />
Crash <strong>Conf</strong>iguration. Car-to-car collisions are overrepresented<br />
in crashes with child(ren) [Figure 4]:46vo of<br />
cases as against 27Vo for all crashes. Conversely, for cars<br />
with child(ren), casualties against fixcd obstacles (trees,<br />
poles, walls, etc.) are half fewer than for all such crashes<br />
(with or without child on board).<br />
s<br />
t5<br />
t0<br />
t0<br />
i5<br />
o.|4<br />
tu++<br />
Figure 4. Brealtdown of ths Varlous Grash <strong>Conf</strong>igurationt<br />
Involving Vehicles with Chlld Passengers (N=275) and<br />
Fercentage ol All Crsshes With or Without Child<br />
Caaualties<br />
In one out of two cases, the car-to-car configurations<br />
are "hcad-on" and in one case out of thrce. "side<br />
configuration".<br />
HI<br />
Type of Impacf. Frontal impact is over-represented for<br />
vehicles occupied by at least one child: 577o for such<br />
cius as against 47 7o for all cars. Converscly, side<br />
impacts represent only 2()1o of impact types for cars with<br />
child(ren) as a8ainst 30Vo for all cars [Figure 5]. Side<br />
impacls occur chiefly against other vehiclcs (against cars<br />
in 43 Vo of cascs, against utility vchicles or public means<br />
of transport in 25Vo of cases) and in only l87o of cases<br />
against fixed obstacles, whereas 44Vo of tatalities in side<br />
impact, for all cars with or without children, are<br />
involved in crashes against such obstacles.<br />
6Or 60 a7<br />
40<br />
3C<br />
20<br />
10<br />
,, n",; ;l;, " *0,;; ", u, ;; * t#:":T';Aril*f**<br />
Creshes Involving Vehicles With Child Passengers<br />
(N=275) and Psrcsntage of All Crashes With or Without<br />
Child Casualties<br />
Severity of Injury according to Type oY tmpact. ie<br />
fatolity ratc of children involved in frontal irnpact is the<br />
lowest of all crash configurations: Fatality rate (F.R.) =<br />
0.17 in frontal impact and F.R. = 0.25 for all impacts<br />
[Table 6].<br />
Table 6. Global Injury Severity According to Type ol<br />
lmpact<br />
TYPE OF<br />
IMPACT<br />
FAf SEVERE<br />
ALI- INJUR-<br />
TTFC IE5<br />
LIGHT<br />
INJUR.<br />
UN.<br />
HARMED<br />
SEVERITY TOTAL<br />
UNKNOWN<br />
FRONTAL b4 t0l 33 240<br />
SIDE 34 r0 29 2 79<br />
REAR<br />
OVERTURNINC<br />
AND ROLLOVER<br />
t5 I 24 3 5l<br />
SIDE SWIPE J<br />
UNCLASSIFI- 8 2 t7 6 34<br />
ABLE & OTHhRS<br />
TOTAL r03 84 t76 49 5 417<br />
In frontal impact, the distribution by cumulative<br />
percentages of the EES is fairly similar for child<br />
fatalities and severe injuries [Figure 6J. The violcnce of<br />
frontal impacts is espccially high in the cilsc o[ fatalities<br />
and severe injurics: 60Vo of them iue involved in impacts<br />
of EES grcater than 55 km/h.<br />
It is in side impact that the tatality rate is highcst: out<br />
of 100 child casualLics, 44 are killed in this type of<br />
impact. Direct intrusion on the part of the passcnger<br />
compartmcnt occupied by the child, and ejection of the<br />
child (following an often localizcd impact on the tiont or<br />
o<br />
5r<br />
!i<br />
r,<br />
:l<br />
i!
lSth lnternatlonal Technlcal <strong>Conf</strong>erence on Experlmentel Selety Vehlcles<br />
rear $tructure of the car), are observed in a large<br />
proportion of side impacts.<br />
* ! 0<br />
;1<br />
;.+<br />
-T<br />
50<br />
Figure u."o,",r,0*,"" ,, c..*;,*" ;"*"";se of E.E.s.<br />
According to Global Severity Injury for Chlldren Involved<br />
in Frontal lmpact<br />
Rear impact, although not frequent, nevertheless<br />
remains scvere. sincc in 5 cascs out of 9 it resulted in<br />
thc dcath of the child. Collisions involving a utility<br />
vehicle caused 4 of these dealhs.<br />
The high fatality rate observed in overturning and<br />
rollover is mainly attributable to ejection. Information is<br />
given further on concerning this type of impact, in the<br />
scction dcaling with ejection.<br />
Severity of Injury according to Seating Position.<br />
Certain trcnds can be observed concerning the global<br />
sevcrity of child injuries according to seflting position.<br />
The lowest scverity is for children located in the central<br />
rear position (F.R. = 0.21). The fatality rates observed<br />
for the outer side positions are fairly similar: 0.27 on the<br />
left and 0.32 on the right [Table 7J.<br />
Table 7. Global Injury Severity According to<br />
Position Occupied<br />
POSITION FAT- SEVERE LIGIIT UN- SEVERITY TOTAL<br />
OCCUPIED ALI-<br />
'IIES<br />
INJUIT-<br />
IES<br />
INJUR'<br />
rh5<br />
HARMED TINKNOWN<br />
FRoNT PoSITION 5 z 4 12<br />
T,EFT<br />
F1 CENTRE<br />
4<br />
E RIGHT<br />
24 21 34 ll 90<br />
v 7 l9 7 42<br />
3l 20 39 8 98<br />
POSITION<br />
UNSPECIFIED<br />
3i 34 75 l6 160<br />
FclsffloN<br />
IINKNOWN<br />
l 5 6 I l5<br />
TOTAL 103 84 ?60 49 5<br />
The greatest severity is observed for children sitting<br />
in the front: 5 of the 12 children sitting in thc front seat<br />
were killed. In two cases. the deaths are attributable to<br />
intrusion. They would undoubtedly have becn prcvcnted<br />
if the child had been sitting in any of the rear-seat<br />
positions of the vehicle. Thrcc other children were<br />
restrained by a 3-point seat belt in the front right<br />
position. Two of them wcrc killed by a frontal impact of<br />
moderate violence (EES of 40 km/h), while the third,<br />
52<br />
aged 9, sustained only light injuries in a frontal impact<br />
estimated at EES approximatety 50-55 km/h.<br />
Comparative Severity ChildrenlAdalts. The global<br />
severity of injuries sustained by adults is higher than that<br />
obscrved for children [Figure 7]. The fatality rate for<br />
adults is close on onc quarter higher than that for<br />
children, for all impacts; it is almost twicc as high for<br />
adults in frontal impact.<br />
-^ FA'|ALITY RATEI-'I<br />
'60 + SEVERITY LEVEL=<br />
.30<br />
i<br />
'to i .el<br />
.30<br />
I .tl<br />
,20it | | |<br />
.'o1l I I I<br />
o||<br />
| | | __.,..+:<br />
CEIDEH ADULTS<br />
: E<br />
CHILOREN ^DULTS<br />
Figure 7. Fetelity Rate and Severity Level for Children<br />
and Adults<br />
The risks incurred by children are comparatively lower<br />
than for adults, because most children are scatcd in the<br />
back positions where frontal intrusion is rare.<br />
Se.verity oJ Injury by Child.Age. The overall injury<br />
sevcrity distribution [Table 8l with age is in line with<br />
what is obscrvcd in all thc litcrature: the smallest<br />
children are the most vulnerable [5]. The highest fatality<br />
ratc is for infants between birth and 12 months. One<br />
observes a fatality rate of 0.44 (Figure 8) for this age<br />
group, as against an avcragc fatality rate of 0.25 for our<br />
entire population of childrcn. The dilfcrcnce is<br />
stittistically significant. For children aged between I and<br />
LZ months, their low tolerance to impact is not<br />
compensated for by more frequent use of specific<br />
restraining systems (28% as against L\o/t, lor all those<br />
aged less than l0). We spccify that in l3 cases out of 14,<br />
the seats were positioned fhcing the road.<br />
Table I. Severity of Injuries Sustained by Children<br />
According to Age<br />
AGE FATALITIH<br />
tq<br />
7<br />
l0<br />
I<br />
l0<br />
I<br />
7<br />
J<br />
l0t<br />
SEWRE<br />
INJUHS<br />
I<br />
!0<br />
II<br />
ll<br />
I<br />
I<br />
9<br />
8a<br />
LIGHT<br />
IN'UHE<br />
I<br />
l8<br />
t8<br />
t{<br />
16<br />
2l<br />
il<br />
176<br />
-?0<br />
,80<br />
'50<br />
,la<br />
Ejection. One out of every three children killed is a<br />
victim of cjcction. Thc frequency of ejection in crashes<br />
is twice as high for childrcn as thc rate observed for<br />
adults: l87o and 87o respectivcly. There are two explanations<br />
for lhis:<br />
. The very unequal rate of use of restraining systems<br />
by children and adults partly explains this finding.<br />
tq<br />
.61<br />
CH[.bhEN ADULTI CHil-DRE{ ADULTS<br />
ucHrLpREN (Nr!rl)/ ^pulrr (Nr3lr) EBql[.\tt_L\l&lj:x<br />
UffiA#EP<br />
I<br />
I<br />
1<br />
J<br />
l<br />
49<br />
SEVERfr<br />
UWOW<br />
-<br />
ffiAL<br />
3l<br />
s<br />
47<br />
45<br />
4l<br />
J8<br />
J6<br />
417
70<br />
60<br />
50<br />
40<br />
30<br />
20<br />
10<br />
o<br />
0 | to2 13to 2vee.t 3y6er6 dydd.g 5v$rr 6yDE 7yiil! By.i.s gy6er6<br />
mon(hs 23<br />
montht<br />
Flgure 8. Fetallty Rate end Severfty Level for Children<br />
According to Age<br />
' The small size of children could be a factor of more<br />
frequent ejection. The ejection rate for the youngest<br />
childrcn (aged less than 6) is slightly higher than<br />
that for older children:21 %' and 17 70 respectively<br />
for unrestrained occupants. For restrained occupants,<br />
the frequency of ejcction, which is 7 Va for children<br />
as against I 7o ejected for adults, may be due partly,<br />
among other causcs which it is impossible for us to<br />
check, to a greater difficulty in rcstraining children<br />
on board cars using existing rcstraining systems of<br />
the seat or booster.<br />
The proportion of ejections occurring in rollover and<br />
in side impact represents over half the cases of ejection<br />
for children [Figure 9].<br />
(30 r)<br />
ROLLOVER<br />
FRONTAL IMPACT<br />
REAf,tMP.{T<br />
OTIIERS AND<br />
INCLASSIFI^BLE<br />
Figure g. Breakdown<br />
of 1fi) Elected Children According<br />
to Type of lmpect<br />
The fatality and severity rates give a measure of the<br />
risk incurred in the event of ejection: 0.5.5 and 0.75<br />
respcctively when ejection is observed as against 0.20<br />
and 0.40 in the absence of ejection. Here again, children<br />
show greater vulnerability, since thc fatality rate is<br />
doubled for ejectcd adults, whereas it is multiplied<br />
almost by 3 for children.<br />
Three of the twelve children located in the front seat<br />
were ejected, as against lTVo for children locatcd in the<br />
rear positions.<br />
Four children restrained by special systenrs were<br />
ejected. Analysis of these files shows that ITable 9J:<br />
(3 i)<br />
<strong>Section</strong> 3: Technlcal SessJons<br />
Tebb 9. Grarh C-haracterlstlcs for Hestreined end Efected<br />
Ghildren<br />
FIE & & INC 5Y5EM I}IPAfr<br />
s-7t<br />
s-t:t<br />
fi.M<br />
01. til<br />
gEftON OF IYIE\t coMltNt<br />
. In 2 out of 4 cases, the system used was a booster<br />
Two of the 4 booster used in thc samplc as a whole<br />
were ejcctcd with the child during the crash.<br />
. No ejection of a restraincd child is obscrved in<br />
frontal impact. On the other hand, when ejection<br />
occurs, in 3 cases out of 4 this is due to side impact<br />
followed by a vehicle spin.<br />
Restraining Systems<br />
Severity and Location of Injuries in Restrained<br />
Children in Frontal Impacts. The head is thc location of<br />
an injury for more than half of the restraincd childrcn<br />
involved in frontal impact [Figure l0].<br />
The other body areas most affccted are the thorax (31<br />
Vo), the abdomen (24o/o) anrl the neck (21 Vo).<br />
Given the absencc of reliable mcdical data for nearly<br />
all the child fatalities, we are unahle to rcach conclusions<br />
concerning thc distribution of faral injuries.<br />
For severc injuries (AfS 3 to 5), abdorninal injuries<br />
are preponderant, being obscrved in very violcnt impacts:<br />
EES in the range between 55 and 70 km/h. For 3 of the<br />
4 victims aged between 7 and 9, the restraining systenl<br />
uscd was the seat belt mounted on board thc vchicle<br />
withcrut any additional boostcr. Thc last victim, agcd ?,<br />
was seated in a torward facing child seat. This child was<br />
the only one of thc 4 victims of severe injuries to the<br />
abdomen that suffcrcd more severe injuries on another<br />
body area (AIS 6 to the head). Thcrc wcrc 3 scvcrc skull<br />
injurics (AIS 3 to 5). ln these crashes, the violence of<br />
frontal impact is high (-55 to 60 km/h), and is unknown<br />
in the last case, which involved exten$ive underriding<br />
under the front of a heavy vehicle For two of these very<br />
young victims (agcd 2 and 3), decease ensued from skull<br />
injuries only.<br />
Restraining Systens and Global Injury Severiry for<br />
Children. The eftectiveness of thc global protection<br />
provided by the use of child restraining systcms has bccn<br />
demonstrated by many studies t6l, t71, [8]. This el'l'ectiveness<br />
is observed with respect both to the frequency of<br />
injuries ilnd the injury severity. These results are based<br />
on studics involving the analysis of crashes of all levels<br />
of severity, which in fact mcans a vcry large proportion<br />
1<br />
I<br />
,j;<br />
':l<br />
r$
lSth lnternetional Technlcal <strong>Conf</strong>erence on Experlmentel Sefety Vehicles<br />
Figure 10. Frequency, Severity and Location of InJuries Sustained by Restrained Unejected Children in Frontal lmpact<br />
(other impacts)<br />
of impacts of low or moderate violence. It was interesting<br />
to check whcthcr the effectiveness of this protcction<br />
was likewise observed for the most severe crashes only.<br />
For all impacts ITable l0], thc fatality rate is situated<br />
within a 99Vo confidence region of 0.19 to 0.51 for<br />
restrained children, as against 0.17 to 0.30 for<br />
unrestrained children.<br />
In frontal impact, the fatality rate is situated within a<br />
confidence region of 0.07 to 0.44 for restrained children,<br />
as against 0.06 to 0.20 tor unrestrained children.<br />
Table 10. Globat Injury Severity for Chlldren According to<br />
Age and Restraining System Ussd<br />
46E CROUP' nIs]ilN-<br />
ING SYSEM<br />
9r<br />
TOT L<br />
Child Hl<br />
FATAffiB<br />
2<br />
t2<br />
ll<br />
-<br />
l<br />
l6<br />
3<br />
5EYtr LIGF<br />
l8<br />
I<br />
t2<br />
?<br />
,i<br />
ffiAWE<br />
i<br />
I<br />
l0<br />
SEVEMY<br />
ffiAL<br />
tl<br />
3<br />
3<br />
s<br />
l0<br />
187<br />
l5 I s l? 67<br />
l0J<br />
g l?6 5 111<br />
One therefore observes no significant statistical<br />
difference whether or not a restraining system was used,<br />
both for all impacts and for frontal impact.<br />
There are several explanations for this.<br />
54<br />
. The conditions of use of the rcslraining systems<br />
(fastening of seats to the vehicles, play in harncss<br />
Frcqucncy Proponion<br />
of complrint df AI5 > l<br />
ls, rs"r<br />
l h" ,rrtl<br />
lrr {fi] | 1ot?} I<br />
Fnr-il f-*,8<br />
l'rsl lTr'rl<br />
| 3,in T-__l<br />
I )r$l<br />
I ," {rl | ." rrrrl<br />
l'"161 Fl<br />
straps, etc.) are not known. We have every reason to<br />
believe that there arc frcquent cases in which the<br />
restrflining systems are not used in accordance with<br />
the recommendations of the manufacturcrs. Many<br />
studies t6l, tgl, tl0l, tlll mentionratesof misuseof<br />
restraining systems which are sometimes very high<br />
[21. Wc also observed this ourselves for the cases<br />
alrcady analyzed by us prior to this study.<br />
. Onc quarter of the child seats uscd datc prior to thc<br />
French regulations of 1985. Of the specific system$<br />
(child seats and seat boostcr), only 21 7o of them<br />
were in compliance with the requirements laid down<br />
by the French car makers [31.<br />
. The influence of violence bias; in frontal impact, 25<br />
7o of restrained childrcn arc involved in impacts of<br />
EES greater than 65 km/h, as against only 7o/o for<br />
unrestrained children.<br />
Thc comparison of global injury severities for children<br />
locatcd in the rcar of the same car. with one child<br />
restrained and the other not [Table I ll, confirms the<br />
trend observed earlier. For thc l9 pairs of children thus<br />
established, the situation most lrequcntly obscrvcd is that<br />
in which the global sevcrity for the restrained child is<br />
identical to that for thc unrcstrained child.<br />
This observation does not allow us to cvaluate the<br />
intrinsic effectiveness of restraining systcms in thc most<br />
violent crashes. This question sets the limit to what can<br />
be expccted of the method used.<br />
Estimated Potential Gains. It is difficult to evaluate<br />
the foresooable potcntial gains from widespread use of<br />
child safety systems. Precise, reliable data is lacking<br />
conccrning child lolcrance to impact (sites and mechanisms<br />
of fatal injuries), and data is also unavailable<br />
concerning the performancc of the restraining systems
Tabfe 11. Oomperkon of Globaf fnfury Saverfty on the<br />
Basis of a Matched Sample of Chitdren Seated in ths<br />
Hear ol the Same Gar (19 pairs of restrained and<br />
unrestrained chlldren on board 15 cars)<br />
UN-<br />
FATAMB<br />
SME<br />
INJUHtr<br />
RESTNECHIDtrE\<br />
LICffi<br />
INJUFJS IJNHAfu\IED TOTAL<br />
FATAMES I I 2<br />
SEVEE<br />
INJUUE I 6<br />
LI6HT<br />
IHJURIES<br />
CHILbEH UffiWED 2<br />
IOTAL 1 5 l9<br />
tested in conditions similar to those of real-world crashes<br />
(type and violence of impacts, in particular;.<br />
We therefore performed, on a case by case basis, an<br />
evaluation of the potential cffcctiveness of a hypothetical<br />
optimized rcstraining system, the main characteristics of<br />
which would be as follows.<br />
' Ejection of the system with the child or of the child<br />
from the system is no longcr possible (the potential<br />
gain is therefore estimated assuming that the child is<br />
rctained in the vehicle).<br />
'The characteristics of the system used by the<br />
youngest childrcn (aged less than 5) are such that<br />
any impact of the child against a part of the<br />
passenger compartment in frontal impact is prevented<br />
(ns with a forward facing seilt). The hypothcsis<br />
adopted, then, is that decease is preventable in all<br />
frontal impacts in the absence of intrusion.<br />
. The systcm is ineffective in all impacts in which<br />
more than 307a intrusion is observed on thc position<br />
occupied by thc child.<br />
Bccause of the complexity of certain crashes or the<br />
absence of suitable data, we have introduced distinctions<br />
in the answcrs which can be obtained by casc-by-case<br />
analysis. For example, we distinguish bctwecn fattlities<br />
which are certainly or pr0bably not preventable.<br />
However, we iue aware of the limitations of this<br />
approach, based on hypotheses which are at present<br />
unvcrifiable, which is why we prefer. instead of<br />
estimating the potential gain obtained with an optimized<br />
system, to count only those impacts in which the system<br />
would have been inoperative.<br />
Thus, for 43Vo of unrestrained child fatalities, the use<br />
of an optimizcd restraining system would have probably<br />
(16%o) or certainly (27V0) changed nothing [Table l2].<br />
The relative ineffcctiveness of such a system in side<br />
impact is not surprising; 647o of the deceases observed<br />
in side impact could certainly not be prevented, due to<br />
the high intrusion levels noted in this typc of impact. It<br />
I<br />
<strong>Section</strong> 3: Technlca/ Sessjons<br />
is in frontal impact and rotlover that an improvement in<br />
the situation can be expected, since only 25Vo of the<br />
deceascs occurring in frontal impact could nol be<br />
prevented. All fatal victims of ovcrturning or rollover<br />
could certainly or probably bc prevented.<br />
Table 12. Estimated Potentiat Gains According toType ot<br />
lmpact<br />
IMPAfr<br />
HO<br />
TROBABLE CERTAN PROBdLE CHT^IH<br />
Fioffi[ 1 9 I<br />
UffiHhffib<br />
SDE 6 t0 6 I I x<br />
HR ,<br />
ovqroNNg,<br />
RQIOVER<br />
dilffid<br />
UNCU5SINABLE<br />
I 5<br />
mT[ lz t0 20 1<br />
9<br />
TOT^L<br />
Conclusions<br />
From the analysis of 275 police reports on fatal<br />
crashes occurring in France in 1990, concerning 417<br />
child casualties aged less than 10, the following points<br />
should be noted.<br />
. Cases of over-occupancy (more than five adults or<br />
children), which have dcclincd greatly over the last<br />
ten yeilrs at least, now represent only 77o in vchiclcs<br />
with children.<br />
' Only 14Vo of children aged less than l0 use a<br />
restraining system.<br />
.40Vo of the children are involved in collisions on<br />
short trips (less than 30 km).<br />
. In car-to-car collisions, the responsibility for the<br />
crash is attributable in only one third of the cases to<br />
the driver with a child passenger. The frequency of<br />
poriitive alcohol levcls above the legal rate is four<br />
times higher for drivcrs wilhout a child compared to<br />
drivers with a child (or childrcn).<br />
The proportion of car-to-car csllisions is overrepresented<br />
in crashos involving children: 46a/a as<br />
against 27Vo for all crashes.<br />
57Vo of impacts are frontal.<br />
. The violcncc of fronlal impacts is particularly high:<br />
60Vo of thc EES values for cars with child(ren) are<br />
greater than 55 km/h.<br />
. On the rear seat of the car, the central position<br />
appears the silfest (fatality rate = 0.21 as against<br />
0.2'7 on the left and 0.32 on the right).<br />
'Thc global severity of the injurics sustained by<br />
adults is grcatcr thiln thilt observed for children.<br />
r!<br />
-T<br />
ii<br />
,t,<br />
'5
13th <strong>Int</strong>ernatlonal Tdchntcat <strong>Conf</strong>erence on ExPerimental Safety Vehicles<br />
. The youngest children are the most vulnerable: thcre<br />
we 44Vo of fatalities for infants aged between I and<br />
l2 months, as against 25Vo for all children aged less<br />
than 10.<br />
. One child out of three killed is the victim of<br />
ejection. The frequency of ejection of children is<br />
twice as high as that observed for adults: lTVo and<br />
8% respectively. For the children, the risk of heing<br />
killed during ejection is three times grcater (587o of<br />
fatalities) than the fatality rate observed in thc<br />
absence of ejection (ZOVI of fatalities).<br />
. In frontal impact, for non-deceased restrained<br />
children:<br />
- The head is the location of an injury for morc than<br />
half of the children;<br />
- or very scvere injuries (AIS 3 to 5), abdominal<br />
injuries are preponderant, and are observed in<br />
victims restrained by the seat belt only.<br />
. No statistical difference is observed in the fatality<br />
rate according to whethcr or not a rcstraining system<br />
is uscd. The misusc of child seats (some of which,<br />
moreover, are old or do tlot comply with the<br />
recommcndations of French car makers) largcly<br />
explains this result, which is the oppositc of what is<br />
observed in othcr countries (Sweden and the U.S-A.<br />
in particular).<br />
. The scope of the potential gain in terms of deceases<br />
which could be prevcnted by an optimized reslraining<br />
riystem is 57o/o of unrestrained child fatalities.<br />
For the other unrcstrained children, the violcnce of<br />
thc impacts sustained by them is such (chiefly strong<br />
intrusion) that the use of an optimizcd restraining<br />
system would have changed nothing.<br />
The global rcsults for child rcstraining systems in fatal<br />
crashes may seem mediocre. However, it must be said<br />
that these results are evaluated without being able to take<br />
into account the specific conditions of use of such<br />
systems. There are strong grounds for thinking that a<br />
large number of restraining systems flre not used in<br />
accordance with the recommendations laid down by the<br />
manufacturers.<br />
That is why wc feel that a substantial improvement in<br />
the child protection levcl must involve a lretter<br />
knowledge of the mcchanisms of fatal injures sustained<br />
bv restrained children. An increase in intcrnational<br />
exchanges of the best documented fatal crash files would<br />
help us make rapid progress in this field, where thc<br />
public health is at stakc.<br />
References<br />
1. Hartemann F., Foret Bruno Jy. et al., "Les Acddents<br />
Mortels en 1980" (unpublished study, Association<br />
Peugeot S.Afienault).<br />
2. Turbel Thomas, "swedish Programs for Child<br />
Protection in Cars" (IRCOBI conference, Stockholm<br />
1989).<br />
3. Langwieder K., Hummel Th., "Children in Cars:<br />
Their Iniury Risks and the Influence of Child<br />
Protection S'y.rtems" (<strong>ESV</strong> conference, Goteborg<br />
lese).<br />
4. Hayes H.R.M. (IRCOBI conference, Stockholm<br />
1989).<br />
5. Lowne R., Gloyns P., Roy P', "The Performance of<br />
Child Restraint Systems in Side Impatts" (T.R.R.L'<br />
May 1987 and <strong>ESV</strong> conferencc, Goteborg 1989).<br />
6. Karlbrink L., Krafft M., Tingvall C. (<strong>ESV</strong><br />
confcrcnce, Goteborg 1989).<br />
?. Partyka S.C., "Lives Saved by Child Safety Seats<br />
from 1982 through 19S7" (NHTSA - 1988 and <strong>ESV</strong><br />
conference, Gotehorg 1989).<br />
8. Tingvall, "Some Asp€ctr of the Safety of Children as<br />
Car Passengers in Road Trffic Accirlenrs" (Acta<br />
Paediatrica Scandinavica magazine- I987).<br />
9. Dejeammes M., Biard R., Carre Jr., Cambon 8., De<br />
Lavalette (INRETS magazine - Francc 1986).<br />
10. Dejeammes M., Trauchessec R. ("L'enfatlt passagcr<br />
d'automobile", symposium in France 1987).<br />
11. PetrucelliF'..<br />
"Child Restraint Misuse in the USA:<br />
Implications for Crash Protectiort" (IRCOBI<br />
conference, 1989).<br />
12. Khanc C.J., "An Evaluation of Child Passenger<br />
Safety: The Elfectiveness and Benefits of Safety<br />
Seafs" (NHTSA study, report DOT HS 806 890,<br />
February 1986).<br />
Acknowledgements<br />
We should like to thank the Police Forces for kindly<br />
providing us with a copy of police rcports on fatal<br />
crashes occurring in 1990. Without their coopcration,<br />
this study would have been impossible.
sr-o-05<br />
Data Analysis of the Speed-Related Crash fssue<br />
Noble Bowie<br />
Marie Walz<br />
National Highway Traffic Safety<br />
Administration<br />
Abstract<br />
Excessive speed has been recognized for decades as<br />
both a significant and complex highway safcty issuc.<br />
Using the most recent data available, this paper examines<br />
the size of the'-speed problem" in the United States and<br />
identifies characteristics most often associated with<br />
speed-related crashes. Data from the National Accident<br />
Sampling System, thc Fatfll Accidcnt Reporting System,<br />
the Crash Avoidance Research Data File, the National<br />
Crash Severity Study, and the Indiana Tri-Level Study<br />
were utilized in conducting the analysis. Information<br />
pcrtaining to crash avoidance, crash severity, and related<br />
crash characterisl.ics (e.g., alcohol, vehicle type, roadway<br />
condition, etc.) wcre examincd. Of particular interest is<br />
the use of an innovative methodology to estimate the<br />
economic impact of speed-related crashes on society.<br />
<strong>Int</strong>roduction<br />
' -'Speed Kills" has been an important slogan for<br />
highway safety. While it is clearly true, it is not a very<br />
useful definition for a highway safety program. To<br />
effectively addrcss the issue, it is imperative to know the<br />
size of the speed-related crash problem, where these<br />
crashes most often occur, why they occur, and who is<br />
most likely to be involved in such crashes. To asccrtain<br />
this information, an analysis of several crash data files<br />
was conducted. This paper presents the rcsults of that<br />
analysis. It examines the speed issue in terms of crash<br />
causation, crash severity, crash characteristics, and<br />
societal costs.<br />
Crash Causation Data<br />
Data from the Crash Avoidance Research Data file<br />
(CARDfile) [1], tne Indiana Tri-Lcvcl study [2], and the<br />
Fatal Accident Reporting System (FARS) [3] wcre<br />
examined to determinc the relative role of speeding in<br />
crash causation. Other than data fronr the Indiana<br />
Tri-Level study, the dam in the problem identification/<br />
problcm size analysis are based on police-reported<br />
information, not detailed investigations. The accuracy of<br />
police-rcportcd data is generally not as good as that<br />
provided by field investigations/crash reconstructions and<br />
this should be kept in mind when interpreting these<br />
results.<br />
CARDfile was developed by NHTSA as an aid to<br />
problem identification and countermeasurc development<br />
in the general area of crash avoidance research. It<br />
Sectlon 3: Technlcal $esslons<br />
electronically combines the annual crash data files of six<br />
States into a common format. For purposes of this<br />
analysis, data from the 1986 CARDfile were utilized.<br />
The I 986 CARDfile data contain about 1.4 million<br />
crashes involving about 2.4 million vehiclcs and drivers.<br />
Data from additional years of CARDfilc wcrc not<br />
included to simplify the analysis, and because previous<br />
analyses have shown that distributions obtaincd in a<br />
single year of data closely reflect distributions based on<br />
several years of data.<br />
CARDfile was analyzed to determine the magnitude of<br />
the role of speed in contributing to crash causation.<br />
Table I compare$ the relative involvement of speed and<br />
other driver errors in contributinu to the occurrence of<br />
crashes.<br />
Table 1. Drlver Error Involvement in Crash Ceusation<br />
Crash Type<br />
$peed-Relatedtt<br />
Right-of-Way Violation<br />
Following Too Closely<br />
lgnore Traffic Control<br />
As lee p/lnattention<br />
lmproper Passing<br />
Failure To Signal<br />
Percent of Crashes ln<br />
Which Factor Was lnvolved'<br />
1'l.6Ye<br />
8.7V"<br />
8.0%<br />
7.1V"<br />
4.'|"/"<br />
2.4%<br />
.9V"<br />
*<br />
Data ar€ based on police accident reporls from six States, and<br />
ere not nationally representative.<br />
"<br />
Speed-related means that in the police officer's judgment<br />
speed contributed to the cause of the crash. Up to three lactors<br />
could be coded for each cra$h.<br />
Source: CARDfile 1986,<br />
As illustrated in the table, speed was found to be<br />
involvcd in close to l2 percent of the crashes in<br />
CARDfile. It was the most prevalent driver crror-rclated<br />
cause contributing to crilsh occurrence.<br />
A similar analysis of dala from the Indiana Tri-Level<br />
study was also performed. In thc Tri-Lcvcl study crirshcs<br />
werc cxamined at three levels: police accident rcports<br />
(level A), on-scelrc invcstigation of crashes by teams of<br />
technicians (level B), and in-dcpth investigations of<br />
subscts of crashes by multi-disciplinary teams (level C).<br />
Also, there were three levels of certainty that a causal<br />
factor contributed to the occurrence of a crash-dcfinite,<br />
probable, and possible. For purposcs of this analysis,<br />
only invcstigation levels B (2,258 cases) and C (420<br />
cases) and certainty levels --definite" and "probablc"<br />
werc used.<br />
The top crash cau$ation factors (includes driver,<br />
environment, and vehicle relatcd factors) were idcntified
ISth //'tematlonel Technlcal Conterence on Experlmental Sefety Vehlcles<br />
and rank ordered. Here, "cause" means a deficiency<br />
without which thc crash would not have occurred. Each<br />
crash could have multiple causes. The factors were rank<br />
ordered by the range of their estimated involvement,<br />
considering the estimated percentage of involvement at<br />
level B definite, level B probable, level C definite, and<br />
level C probable. The highcst and lowest figures for each<br />
causal factor were then used to represent its overall<br />
range of involvement (see Table ?).<br />
Trble 2. Rank Order of Causel Factore by Hange of<br />
Involvement<br />
Causal Factor Range of lnvolvement<br />
(percent)<br />
lmproper Lookout<br />
Excessive Speed*<br />
Inatt€ntion<br />
Slick Roads<br />
lmproper Evasive Action<br />
13.0 - 23.1<br />
7.1 - 16.9<br />
8.4 - 15.0<br />
3.8 - 14.1<br />
4.5 - 13.0<br />
'Excessive speed means too fast for conditions. lt was not<br />
determined with reference to the prevailing speed limit.<br />
Seurcs: Indiana Tri-Level Study. 1979.<br />
The table shows that *'excessive<br />
speed" was the second<br />
most prevalent factor contributing to crash causation in<br />
the Tri-Level study. The mid-point of the range of<br />
involvement (7.1 - 16.9) for "excessive<br />
speed" is 12<br />
percent which corroborates the CARDfile estimate that<br />
speed is involved in close to 12 percent of all crashes<br />
occuning in CARDfile States.<br />
Tri-Level data were also analyzed by crash type (e.9.,<br />
head-on, anglc, sideswipe, rear-end, and single-vehicle).<br />
For each crash type, the top causal fflctors were rank<br />
ordered hy their percentage of involvcment. Table 3<br />
shows where<br />
"excessive<br />
speed" ranked as a contrilluting<br />
factor in each of thc respective crash types.<br />
Table 3. Ranklng ol Excessive Speed by Crash Type<br />
Crash Type Flanking Range of Involvement<br />
Single-vehicle<br />
Head-on<br />
Sideswipe<br />
Angle<br />
Rear-end<br />
#1<br />
#2<br />
#?<br />
#10<br />
#10<br />
Source: Indiana Tri-Level Study, 1979.<br />
22.1 - 39.3<br />
12.7 - 22.0<br />
r0.B - 14.9<br />
3.4 - 8.8<br />
e.9 ' 6.6<br />
"Excessive<br />
speed" rankcd in the top ten contributing<br />
factors for cach crash type. This is especially noteworthy<br />
given there were approximately 50 factors that could be<br />
considcrcd in each crash case. Of furthcr significance,<br />
58<br />
"excessive<br />
speed* was the first or second most prevalent<br />
cause listed for the two most severe crash typeshead-on<br />
and single-vehiclc crashes. This suggests that<br />
not only is "excessive<br />
speed" a leading cause of motor<br />
vehicle crashes, but it is most prevalent in the more<br />
severe crash types.<br />
FARS data were utilized to determine the role of<br />
speed in contributing to fatal crash causation. FARS is<br />
a censu$ of people who die within thirty days of a motor<br />
vehiclc crash as a result of injuries received in the crash.<br />
The data are prepared by the States from death certificates,<br />
hospital records, police reports, and other sources<br />
and are compilcd by NHTSA into a national data file.<br />
For FARS data, "speed-related"<br />
was defined as "driving<br />
too fast for conditions or in exccss of the posted speed<br />
limit," and "high spccd police chase." (Note that thcse<br />
are qualitative variables that are subject to interpretation<br />
on the part of the data coder. Quantitative variables such<br />
as travcl speed and speed limits were not used because<br />
there are a substantial number of cascs for which this<br />
information is unknown.) Thesc data indicate that in<br />
1989, approximately one-third of all fatal crashes wcre<br />
speed-related. This perccntage has declined from a high<br />
of 39 percent in 1979. Since 1982, thc proportion of<br />
speed-related crashes has basically remained stable. This<br />
is illustrated in Figure l.<br />
Percent SFcd.Rclatd<br />
r9?9 1980 l98l 198? 1983<br />
\GAR<br />
Source: Fatal Accident Hepofting System,<br />
Figure 1. Speed'Helated Fatal Crashes<br />
Crash Severity Data<br />
Thc laws of physics tcll us that the energy of impact<br />
delivered to vchicle occupants in a collision increases<br />
non-linearly with impact speed. Simply stated, crash<br />
severity increases (disproportionately) with vehicle<br />
speed.<br />
To determine real-world crash experience, an analysis<br />
of data from the National Accident Sampling System<br />
(NASS) [4] and the National Crash Severity Study<br />
(NCSS) [5] was conductcd. Through the use of field<br />
investigation teams, NHTSA's NASS systcm collects<br />
detailed data on a nationfllly representative samplc of all<br />
police-reported crashes (the system was reviscd in 1987
and now consists of two comFonents, the General<br />
Estimates System and the Crashworthiness Data System).<br />
NCSS was a NHTSA data collection program that wa$<br />
conducted between 1977 and 1979. Crashes were<br />
investigated in seven geographic locations across the<br />
country. Detailcd information was collected on over<br />
I 1,000<br />
*'tow-away"<br />
crashcs.<br />
In Table 4, the percentage of occupants sustaining<br />
Abbreviated Injury Scale (AIS) 2+ and 3+ injuries is<br />
given for various Delta V levels. AIS is a system for<br />
rating the severity of individual injuries. AIS levels<br />
range from I for a minor injury to 6 for an injury that is<br />
not currently survivable. Delta V is a computed estimate<br />
of the instantancous change in velocity of the vehicle<br />
during the impact phase of the crash.<br />
Table 4. Inlury Rates by Grash Seyerily*, Gomparison<br />
of NCSS & NASS (1s82-8e)<br />
AIS 2+ AIS 3+<br />
Total<br />
Delta V NCSS NASS NCSS NASS<br />
1-10 mph<br />
1 1-20 mph<br />
21-30mph<br />
31-40 mph<br />
41-50 mph<br />
Over $0 mph<br />
2.4%<br />
9.5%<br />
25.3Vn<br />
51.8%<br />
70.3V"<br />
64.7V"<br />
4.5%<br />
10.6%<br />
29.2V"<br />
sg.4v"<br />
67.2"/"<br />
69.3%<br />
0.7"/"<br />
3.5%<br />
1S.9%<br />
s7.2%<br />
58.3%<br />
56.9%<br />
1.O'1"<br />
2.6'1"<br />
1 1 .1"/"<br />
27.9"/"<br />
40.6V"<br />
54.3Vr<br />
*Rate equals the number of occupants et a certain Delta V level<br />
(in 10 mph increm€nts) injured at specilic AIS levels (AlS 2+ or<br />
AIS 3+) divided by the total number of occupant$ involved in<br />
crashes at that level of Delta V tim€B 100. Does not include cases<br />
in which either the Delta V level or the AIS level was unknown.<br />
Sources: NASS 1982'86, and 1988-89 (CDS) Includes only<br />
tow-away cases. There was no slatistically representative NASS<br />
file in 1987. (See Appendix 1 for sample sizes and standard<br />
errort.) NCS$, 1979. Data are limited to low'away crashes<br />
involving pa$senger cars and light trucks. Data ar€ not nationally<br />
rBpressntativs.<br />
Both NCSS and NASS data show a consistent and<br />
dramatic increase in injury severity as Delta V level<br />
increases. For instance, people involved in crashes with<br />
a Dclta V of 50 mph or grcater are morc than -50 timss<br />
more likely to sustain an AIS 3+ injury than those<br />
involved in a crash with a Delta V of l0 mph or lcss.<br />
Clearly, the crash data are evidence that real-world crash<br />
experience follows the laws of physics-<br />
In terms of crash severity, the most critical real-world<br />
measure is how many injuries and fatalities result from<br />
speed-related crashes. To determine this, data from the<br />
NASS General Estimates System (GES) file, FARS and<br />
CARDfile were analyzed. First, GES was referenced to<br />
obtain nationally representative estimates of the number<br />
of occupant injuries for the various police-reported<br />
injury severity levels. CARDfilc, bccause of its large<br />
number of cases, was referenccd to determine the<br />
proportion of occupant injuries for cach injury severity<br />
Sectton 3: Technlca/ Sessions<br />
level that is speed-related. The CARDfile percentage$<br />
were thcn applied to thc overall GES estimates and<br />
FARS data to dcrivc thc number of occupant injuries for<br />
each injury severily level that are speed-rclated. The<br />
FARS file was then used to obtain the total number of<br />
motor-vehicle crash fatalities, and the number that were<br />
speed-related. This is illustrated in Table 5.<br />
Table 5. Dletrlbutlon of Inlurles In Speed-Helated<br />
Crashes by lnJury Severity Level<br />
Injury $everity<br />
Level Frequency' Speed-Related.' Total<br />
No Injury"' 12,610,000<br />
Possiblelnjury 1,719,000<br />
Non-lncepacitating<br />
tniury 943,O0O<br />
Incapacitating Injury 481,000<br />
Fatal lnjury'--' 45,500<br />
1O.2"/"<br />
10.9%<br />
1tI.6%<br />
17.1V"<br />
34.2V"<br />
1,286,220<br />
187,371<br />
137,67S<br />
82,25 1<br />
15,558<br />
'National totals are from 1989 GES. (See Appendix 1 for<br />
sample sizes and standard errors.)<br />
-'Speed-related pBrcentag€ derived from CARDfile (1984-<br />
1 986).<br />
"-The<br />
estimate lor non-injured people is coneidered to be low<br />
because some states only list injured persons.<br />
****Fatal crash statistics ere from FAFIS, 1989.<br />
Based on the information in Table 5 it is estimated<br />
that in 1989, 15,558 people died in spccd-rclatcd crashes<br />
and over 80,000 sustaincd incapacitating injuries. The<br />
injury estimates may be conservative because they do not<br />
include cases in which the occupant's injury severity<br />
levcl was not known. We did not flttempt to includc thc<br />
"unknowns"<br />
because it can not be assumed that the<br />
injury scvcrity levcl distribution for these cases is the<br />
same as for those cases for which the injury severity<br />
level is known. lt should be recognized that many of<br />
these crashes also involved other contrihuting factors<br />
such as alcohol, slick roads, and driver inattention. Note<br />
also that involvement of speed as a contributing factor<br />
increases with injury severity. Only I I percent of vehicle<br />
occupants sustaining possible injury wcrc involved in a<br />
speed-related crash, while more than one-third of fatally<br />
injurcd occupants were involvcd in a speed'related crash.<br />
Crash Characteristics<br />
An analysis of the 1989 FARS file was conducted to<br />
identify the characteristics most associated with speedrelatcd<br />
crashcs. FARS data were utilized because it is a<br />
census of all falal crashes and thc lcvcl of investigation<br />
by the police for fatal crashes is generally greater than<br />
for less severe crashes. As a result, the following<br />
analysis is descriptive of fatal crash situations and may<br />
not be indicative of other crash severity levels.<br />
Manner of Collision - Spced-related fatal crashcs most<br />
often involve only a single vchicle. Almost 70 percent of<br />
all drivers involvcd in spced-rclatcd fatal crashcs wcre<br />
involved in a single vehicle crash. The next highest<br />
percenlages are for head-on (12 percent) and angle<br />
59<br />
"r<br />
Ll<br />
t. r.<br />
-1<br />
l<br />
":<br />
-T
lSth lnternetlonal Technlcal <strong>Conf</strong>erence on Experlmental Safety Vehlcles<br />
crashes (ll percent). For fatal crashes that were not<br />
speed-related, only 35 percent of the drivers were<br />
involved in a single vehicle crash, while 30 percent were<br />
involved in an angle crash and 23 percent were involved<br />
in a head-on crash.<br />
Vehicle Type - FARS data indicate that among vehicle<br />
types, speed-related crashes are most frequently<br />
associated with motorcycle drivers. Over 45 percent of<br />
all motorcycle drivers involved in fatal crashes were<br />
speeding. The involvement of speed in fatal crashes for<br />
motorcycles is almost twice as much as for drivers of the<br />
next vehicle type, passenger cars and light trucks (23<br />
percent). Speeding was found to be much less likely for<br />
drivers of medium and heavy trucks involved in fatal<br />
crashes (ll percent).<br />
Alcohol Involvement - Alcohol involvement was found<br />
to be very prevalent in drivers involved in speed-related<br />
fatal crashes. Approximately 41 percent of all drivers<br />
under the influence of alcohol who were involved in a<br />
fatal crash were speeding or going too fast for<br />
conditions. Of all drivers involved in speed-related filtill<br />
crashes, about 56 percent were under the influence of<br />
alcohol. Conversely, of all drivers involvcd in fatal<br />
crashcs that were not speed-relatcd, only 24 pcrccnt wcrc<br />
under the influence of alcohol.<br />
Safety Belt Usage - Manual safety belt usage (lap belt<br />
or lap and shoulder belt) for drivers involved in<br />
speed-related fatal crashes was found to be only 19<br />
percent. This compares to a usagc ratc of 37 pcrccnt lor<br />
drivers involved in non-speed related fatal crashes. The<br />
number of cases involving automatic restraint equipped<br />
vehicles was insufficient for developing any reliable<br />
estimate.<br />
M()lorcycle Helmet Usage - Little difference was<br />
found in motorcycle helmet usage for speeders and nonspeedcrs.<br />
Of all motorcycle drivers involved in speetlrelatcd<br />
fatal crashes, 40 percent were wearing helmets.<br />
In fatal motorcycle crashes that did not involve speed,44<br />
percent of the motorcycle drivers were wearing hclmets.<br />
Roadway Type - About thirty-four pcrcent of all fatal<br />
crashes on known roadway types were spccd-rclated.<br />
These percentages varicd considcrably by road typc. with<br />
thc pcrcentage of those speed-related being greater in<br />
rural settings, except for "Other Principal Arterial<br />
Roads," where it was greater in urban settings. Approximatcly<br />
36Vo of all fatal crashes on rural roads were<br />
spced-related, while only 307o were speed-related on<br />
urban roads. While rural roads account for only 40<br />
percent of all vehicle miles travelled, they account for<br />
6lVo of all spccd-related fatal crashes. Finally, the<br />
highest percentage of speed-related fatal crashes among<br />
the roadway types was on "Local Roads/Streets" and<br />
"Collectors"<br />
(39 percent).<br />
Roadway Surface Condition - About 14 percent of all<br />
fatal crashes occur on wct roads. It makes no difference<br />
60<br />
whether the crash is speed-related (14 percent) or not (14<br />
pcrccnt). Of all fatal crashes occurring on dry roads,<br />
about one-third are speed-related. The same is true for<br />
fatal crashes occurring on wet roads.<br />
Roadway Alignment - Speed-related crashes account<br />
for only 27 percent of all fatal crashes on straight<br />
roadway sections, but constitute 54 percent of all fatal<br />
crashes occurring on curyes. Approximately 40 percent<br />
of all speed-related falal crashes occur on curves, while<br />
only l8 percent of the fatal crashes that are not spccdrelated<br />
crashes occur on curves.<br />
Time of Day - While only 27 percent of all daytime<br />
fatal crashes are speed-related, 39 percent of nighttime<br />
fatal crashes involve speed. Sixty-four percent of all<br />
speed-related fatal crashes occur at night, while 50<br />
percent of all fatal crashes not involving speed occur at<br />
night.<br />
Sex and Age - Male drivers were more likely than<br />
female drivers to be involvcd in a speed-relatcd fatal<br />
crash. About 25 percent of all male drivers involved in<br />
fatal crashes were speeding or going too fast for<br />
conditions. The percentagc for female drivers involvcd<br />
in fatal crrshes wns only l6 percent. Speed-related fatal<br />
crashes were also most associated with young drivers.<br />
Further, the relative proportion of speed-related crashes<br />
was found to decrease with increasing driver age.<br />
Approximately 37 percent of all drivers aged 14-19 years<br />
involved in fatal crashes were speeding or going too fast<br />
for conditions. Thc pcrccntagc for drivcrs 70 and over<br />
involved in fatal crashes was only 7 percent. The<br />
pcrccntages for the various age groups were as follows:<br />
t4-t9 (37Vo),20-29 (30Vo).30-39 (22o/o), 40-49 (16%),<br />
50-59 (127o),60-69 (1070), and70+ (77o).<br />
Number of Vehicle Occupants - FARS data indicrrte<br />
thflt the number of vehicle occupants does not affect a<br />
person's propensity to speed. The percentage of vehicles<br />
with only one occupant was about the same for vehicles<br />
that were speeding (56Vo) as it was for vehicles thal were<br />
not speeding (59o/o).<br />
Frevious Vittlalions - An analysis of drivers with<br />
previous citations shows that in all cases, a greater<br />
pcrccntage of drivcrs involved in speed-related fatal<br />
crashes had previous violations as comparcd to those<br />
involved in fatal crashes that were not spced-relflted.<br />
This is illustrated in Table 6.<br />
Table 6. Drivers in Fatal Crashes by Previous<br />
Violetions and $peed-Related Involvement<br />
Previous<br />
Violation<br />
DpeBorng uonv<br />
Moving Violtn<br />
DWI Convict.<br />
Suspension<br />
Source: FARS, 1989.<br />
Speed-Related<br />
cra$he6<br />
;J4"/o<br />
27"/"<br />
12%<br />
23%<br />
Non Speed-Flelated<br />
Crashss<br />
?a"h<br />
21"/"<br />
8o/o<br />
15"/"
Societal Cost of Speed-Related Crashes<br />
An innovative approach was employed to estimate the<br />
economic impact of speed-related motor vehicle crashes.<br />
This approach involves the conversion of maximum<br />
Abbreviated Injury Scale (MAIS) levels to policereported<br />
injury severity levcls, and applying societal cost<br />
estimates to the injured occupant totals for each injury<br />
severity level.<br />
Estimates of societal cost are based on statistics<br />
considered to be the most authoritative and up-to-date by<br />
NHTSA's Office of Plans and Policy. An articlc by<br />
Miller, Luchter, and Brinhnan [6] provided estimates of<br />
thc average societal economic loss associated with<br />
individual injuries of various maximum AIS levels.<br />
These figures are based on the sums of the following<br />
categories of economic costs: property damage, medical<br />
costs, lost productivity, emergency services, legal/courts,<br />
and other administrative costs. The Miller et al estimates<br />
are prescnted in Table 7.<br />
Table 7. Socistal Economic Loss Per Injury by MAIS<br />
Level<br />
MAIS 1:<br />
MAIS 2:<br />
MAIS 3:<br />
MAIS 4:<br />
MAIS 5:<br />
FATAL:<br />
$2,860<br />
$8,058<br />
$19,48e<br />
$155,832<br />
$391,314<br />
$425,406<br />
Using 1982-1986 NASS data, NHTSA's National<br />
Center for Statistics and Analysis (NCSA) convcrted<br />
MAIS injury levels to police-rcportcd injury severity<br />
levels. This allows one to apply the above MAIS societal<br />
cost estimates to police reported injury sevcrity levels.<br />
Using injury totals from NASS and the societal cost<br />
estimatcs in Table 7, an averagc cost for police-reported<br />
injury level was computed. This is provided in Table 8.<br />
Table 8. Socletal Economic Lo$s Per Inlury<br />
(Pollce-Reported)<br />
No lnjury:<br />
$260'<br />
Possible Injury (C):<br />
$3, 1 04<br />
Non-incapacitating Injury (B): . .<br />
Incapacitating Iniury (A):<br />
$4,656<br />
$20,s3?<br />
Killed(K); ..... $409,031<br />
'There<br />
is an injury cost because in some cases where the<br />
police ollicer r€port€d no injury, sub$equent inlormation (such a$<br />
the hospital r6port) showsd the victim sustained an injury of some<br />
AIS level. Ettimate do€s not include property damag€ costs.<br />
To calculate the total economic loss to the country due<br />
to spced-related crashes, thc occupant injury estimates<br />
developed undcr the Crash Severity scction of this paper<br />
were multiplied by the corresponding societal cost<br />
figures (see Table 9).<br />
Sectlon 3: Technlcal Sesslons<br />
Table 9. Estlmated Societel Cost of Speed-Relatsd<br />
Crashes (1SBS)<br />
No Injury: 1,286,220 X $eS8'=<br />
C injuries: 187,571 X $9,104 =<br />
B injuries: 137,678 X$4,656=<br />
A inluries: S2,251 X $20,532 =<br />
K injuries: 15,558 X $409,031 =<br />
Total Societal Cost of Speed-Related<br />
Crashes =<br />
$1,077,852,360<br />
581,599,584<br />
641,028,768<br />
1,688,777,532<br />
6,363,704,298<br />
$10,352,962,542<br />
'lncludes $260 in injury costs and $578 avorago cost Per<br />
property damage only crash.<br />
Using this approach, it is estimated that speed-related<br />
crashes cost society morc than $10 billion in 1989. This<br />
is a "conservative" estitnate because: (l) it does not<br />
include cases in which the injury lcvel was not known;<br />
(2) thc estimate for non-injured people is low because<br />
some states only list injured persons; and (3) the cost<br />
figures address economic loss only and do not consider<br />
the intrinsic value of life and health abovc and beyond<br />
economic considerations.<br />
Summary of Data Analysis<br />
It is always a sound practice to focus one's problem<br />
solving resources on the largest problems. The priority<br />
setting proccss for highway sitfcty programs centers on<br />
the observed incidencc of a given factor's involvemcnt<br />
in contributing to thc occurrence of crashcs, injurics, and<br />
fatirlities. The use of rcal-world crash data plovides<br />
insight critical to the conduct of meaningful analysis and<br />
safety improvement development. As previously stfltcd,<br />
the purTose of this analysis was to utilize current crilsh<br />
data files to scopc the size of the "speed problctn" and __)<br />
identify pertinent crash characteristics most often<br />
associated with spccd-rclated crashes.<br />
Results of this analysis clearly indicate that the speed<br />
issue warrants priority attention. Speeding/excessive lI<br />
spced is one of the most prcvalent factors contributing to I<br />
crash occurrencc. It is estimated to hc involved in :<br />
approxinrately 12 percent of all police-reported crashes. r<br />
Thc prevalence of its role appcars lo increase with crash I<br />
severity. Whilc only l0 percent of vehiclc occupants<br />
$ustaining no injury were involved in a spced-related ,r<br />
crash, more than one-third of all fatally injurcd<br />
ri<br />
occupilnts werc involved in a speed-rclated crash. In<br />
1989, it is estimatcd that about 15,558 fatalities and<br />
80,000 serious injuries occurrcd in speed-related crashes. :<br />
Thc cconomic cost of these crashcs was over $ l0 billion.<br />
The results also suggest that the specific irspects of the ,<br />
issue that should be focused upon whcn considering tt<br />
potential countermeasures include: ( 1) singlc-vehicle -:<br />
crashes; (2) alcohol involvement; (3) nighttime; (4) rural .<br />
roads;(5)lowsafetybc|tusage;(6)motorcyclcs;(<br />
male drivers; (8) young drivers (under 30); and (9) -t<br />
drivers with previous traffic violirtions.<br />
r;<br />
6l<br />
4
lflth lnternetlonel Technlcal <strong>Conf</strong>erence on Expeilmentel Selety Vehlcles<br />
ReferenceS<br />
4. National Accident Sampling System (NASS),<br />
National Highway Traffic Safety Administration,<br />
l. crash Avoidance Research Data file (cARDfile), 1982-1986, 1988.<br />
National Highway Traffic Safety Administration, 5. National Crash Severity Study (NCSS), National<br />
1984-1986.<br />
2.<br />
Highway Traffic Safcty Administration,l9'7'7-L979.<br />
"Tri-Level Study of the Causes of Traffic Acci- 6. "Crash Costs and Safcty Invcstmcnt", Ted R. Miller,<br />
dcnts", Treat et. al., Prepared for the National Stephen Luchtcr, and C. Philip Brinkman, Presented<br />
Highway Traffic Safety Administration, May 1979. at the Association for the Advancement of Auto-<br />
3. Fatal Accident Reporting System (FARS), National motive Medicine Annual Meeting, September, I988,<br />
HighwayTrafficSafetyAdministration,l9T9-1989. Seattle,Washington.<br />
Appendix I<br />
Sample Sizes and Standard Errore lor NASS Data in Table 4<br />
AIS 2+ AIS 3+<br />
Total<br />
Delta V Percent Staldafd Effor* @11[ Shndard Error* Sample Size<br />
1-10 mph 4.5<br />
ll-20 mph 10.6<br />
2l-30 mph 29.2<br />
3l-40 mph 53.4<br />
4l-50 mph 67.2<br />
Over 50 mph 69.3<br />
1.4<br />
1.9<br />
6.3<br />
14.5<br />
39.1<br />
+rft<br />
1.0<br />
2.6<br />
1l.l<br />
21.9<br />
40.6<br />
54.3<br />
.9SVo<br />
1.1<br />
4.?<br />
18.4<br />
40.5<br />
{. rii<br />
10,814<br />
15,364<br />
4,238<br />
1,031<br />
224<br />
102<br />
*The standard errors were derived from a single year, 1984. These estimates are probably larger than samplc enors<br />
from all years of NASS in this analysis. Multi-year sampling error estimatcs are currently bcing dcveloped. For more<br />
information on the sample design and estimation methodology, contact NHTSA's National Center for Statistics and<br />
Analysis.<br />
**Sample size is insufficient to allow calculation of sampling error.<br />
Sample Slzes and Standard Errors for NASS Data in Table 5<br />
Jniury Scvcrity Lcvcl Frequency Sample Sizg Standard Error<br />
No Injury 12,610,000 N/A* N/A*<br />
Possible Injury 1,719,000 13,345 9I,000<br />
Non-Incapacitating Injury 943,000 I I ,632 56,000<br />
Incapacitating Injury 481,000 5,718 60,000<br />
Fatal Injury*** 45,500 N/4++ N/A**<br />
*No confidence bounds were derived for this figure because some states only list injured persons. Therefore, as noted<br />
in the papcr, thc estimate of non-injured occupants is considered low.<br />
*+Standard errors are not derived for FARS data bccausc thc filc is a census of all fatal crashes, not a sample.<br />
62
sr.0{6<br />
Cvclists and Pedestrians in The Netherlands:<br />
Different Needs of Injury Protection?<br />
<strong>Section</strong> 3: Technlca/ Sessions<br />
L.T.B. Ynn Kampen<br />
Some aspects of this enormous national effort are<br />
SWOV Institute for Road Safety Research improvements in the field of infrastructure (even more<br />
bicycle lancs), of parking facilities and of anti-theft<br />
improvement. Othcr pafls of this Masterplan are<br />
Abstract<br />
improvement of the safety of bicycles and of bicycle<br />
A series of anatyses of injury data from hospitalized<br />
riders.<br />
cyclists and pedestrians based on Dutch national hospital<br />
In view of the relatively high injury risk of cyclists,<br />
data has been carried out. The main purpose of the study<br />
the Dutch Masterplan includes strategies to improve this<br />
is to establish the (different?) nccds of injury protection<br />
situationl in fact the study reported in this papcr is part<br />
of cyclists and pedestrians, especially those colliding<br />
of the Masterplan.<br />
with cars. Contrary to the expectation based on the use<br />
of national accident data, there appeared to be an<br />
The<br />
enormous number of hospitalizcd cyclists resulting from<br />
Problem of the Unregistered Accidents<br />
Ofticial accident statistics do not reflect the truth;<br />
non- motor vehicle coll isions. Their under-representation<br />
in the national accident statistics appeared cven greater<br />
there has always heen much underreporting of non-motor<br />
than the under-representation of hospitalized cyclists and<br />
vehicle accidents and of all types of minor accidcnts'<br />
pedestrians in general.<br />
Howevcr, evcn accidents involving both motor vehicles<br />
This group of patients was analyzed as an additional<br />
and bicycles appear to be hcavily underreported (Hanis'<br />
third group. Conclusions regarding the specific injury<br />
1990). This phenomenon is not unique for thc Nether-<br />
patterns of the three groups, including influence of age,<br />
lands but in view of the great amount of bicyclcs and the<br />
are tlrawn. Recommendations regarding the problcm of<br />
resulting tratfic and traffic accident situation to be<br />
underreporting and the means of protection<br />
monitored, this could be called a major disaster.<br />
against<br />
collision forccs are given. This study forms part<br />
The<br />
of a<br />
Dutch national accident statistics for 1989 show<br />
national plan regarding the stimulation of the use of<br />
a number of 3450 hospitalized bicycle victims, while<br />
bicycles in the Netherlands (CYCLE MASTERPLAN),<br />
according to the hospitals' own datl sourcc there were<br />
in which plan the improvcment of traffic safety of<br />
some 6820.<br />
cyclists and the bicyclc is cxplicitly aimed for. The study<br />
In othcr words:<br />
is carried out on behalf of the Dutch Ministry of<br />
Almo.st half of all bicyde casualties, admined for<br />
Transport, Traffic Engineering Department (DVK). tre(ttment (longer thun one day) in hospitals, ilre nol<br />
found in police rlalirticJ. A comparablc problem exists<br />
for pe dcstrians. Since complctcness of registration<br />
<strong>Int</strong>roduction<br />
decreases with decreasing seriousness of thc accident,<br />
Bicycling in the Netherlands is as normal as walking<br />
the situation is even worse for so called minor bicycle<br />
and sleeping. Almost everyone, from the youngest to the<br />
and pedestrian accidents.<br />
oldest, owns a bicycle; there are some 14 million of<br />
In this paper reliable data on hospital patients are used<br />
them, compared to about 15 million pcople in the<br />
to illustrate the real problem: Almost 1007o of all Dutch<br />
Netherlands. The number of cars is less than half the<br />
hospitals join a datl system that includes relevant data of<br />
number of bicycles. Togcther they are the most common<br />
atl pirticnts admitted for at least onc day treatment.<br />
means of transportation in the Netherlands. Despite this<br />
Apart from such obvious data as age and scx this<br />
fact car drivers and cyclists are not rcally on speaking<br />
source provides extcnsive injury data codcd according to<br />
terms. Their meetings in traffic are often regarded by<br />
the WHO-ICD system and some rclcvant accident data,<br />
both parties as unpleasant encounters. The numbcr of<br />
also coded according to thc ICD system, in particular the<br />
near misses is enormous and accident statistics show a<br />
external causes of injury systcm, so called E-codcs.<br />
great proportion of collisions between the two Sroups' The Dutch organization rcsponsible for the registration<br />
The Dutch governmenl, being very much involved in<br />
and distribution of hospital data is called SIG, the data<br />
the process of controlling and guiding the traffic<br />
file is called LMR. SWOV receivcs a computer tapc<br />
mobility, is trying to get car drivers out of their cars and<br />
copy of the rclcvant data on a yearly base.<br />
into such modes of traffic as public transport, especially<br />
during rush hours. For short trips bicycle use is<br />
stimulated.<br />
Data Selected<br />
As has been mentioned in the Dutch Status Report, a For the analysis reported in this papcr, three groups<br />
national policy catled MASTERPLAN F/EIS (CYCLE were selccted out of the total group of hospitalized<br />
MASTERPLN'I) has recently been designed to improve traffic casualties for thc year 1989. This total number in<br />
all aspects of cycling and bicycles in the Nethcrlands. the Netherlflnds averages around 20.000 each year-<br />
63
lSth <strong>Int</strong>ernatlonal Technlcal <strong>Conf</strong>erence on Experimentel Satety Vehicles<br />
Setected were:<br />
Bicycle casualties resulting from motor-vehicle<br />
accidents (B-MV)<br />
Pcdcstrian casualties resulting from motor-vehicle<br />
accidenrs.<br />
Bicycle casualties resulting from non-motor<br />
(P-MV)<br />
vehicleaccidents .... (B-NMV)<br />
The third group of cyclists was originally not included<br />
in the analysis design, since the problcm to bc studied<br />
focussed on motor-vehicle collisions. These flre reported<br />
to cause 60 to 70Vo of all serious casualties amongst<br />
cyclists.<br />
Howgver, in view of the great number of resulting,<br />
not-included cyclists, this rest-group had to be studied<br />
more carefully and it was found that:<br />
. the rest-group is by far the greatest separate trafficcasualty<br />
group in hospitals<br />
' thc rcst-group shows some interesting differences<br />
with the motor-vehicle casualties<br />
In the official policc accidcnt data the group of nonmotor<br />
vehicle casualties admittcd to hospitals is almost<br />
non-existent! !<br />
In other words official accident statistics do not only<br />
lie, they give a totally wrong impressiorr of the distribution<br />
of accident type.<br />
Therefore they could lead to, and in fact have partly<br />
been leading to incorrect prioritie$ in traffic safety<br />
policy.<br />
Some additional explanation regarding the three<br />
selected casualty groups may be useful for the record:<br />
Thc groups are selected from the main data sourcc, using<br />
E-codes: E 814.0 for the pedestrians against motorvehicles;<br />
E 813.1 for the cyclists against motor-vehicles;<br />
and E 826 for the'-rest-group" of cyclists.<br />
Especially the latter group is a mixture of at least two<br />
separate casualty groups: I. those collicling with other<br />
road users (not motor-vehicles!) such as pedestrians and<br />
othcr cyclists; and 2. thosc hitting obstaclcs or no other<br />
party at all (falls). All these casualties were injured<br />
severc cnough to necessitatc hospital admittance.<br />
Numbers of Selected Casualty Groups, 1989<br />
(Total number of hospital traffic casualties<br />
Number of selected B-MV casualties<br />
Number of eelected P-MV casualties<br />
Number of selected B-NMV casualtiss<br />
20689)<br />
2072<br />
1737<br />
4422<br />
Using thc sclcction critcria mcntioned abovc, some<br />
474 pedestrian casualties and some 324 cyclists were not<br />
included in the 3 groups, because of their different<br />
accident type.<br />
64<br />
General Characteristics of the Selected<br />
Casualty Groups<br />
In this paragraph the distributions of 5 characteristics<br />
are shown:<br />
. age-group<br />
r sex<br />
r Average number of injuries<br />
' where discharged<br />
. length of stay in hospital<br />
The distributions are presented<br />
in the following 5<br />
tables.<br />
Table 1. The 3 Casualty Groups by Age-Group<br />
(Absolute Numbers and Percentages) 1989<br />
Age-Group<br />
(years) B-MV F-MV B.NMV<br />
0 - 15<br />
16 - 17<br />
479 (23,1)<br />
133 ( 6,4)<br />
1B-24<br />
25 - 34<br />
3s - 44<br />
45 - 54<br />
55 - 64<br />
2S2 (12,6)<br />
157 ( 7,6)<br />
137 ( 6,6)<br />
168 ( I,r)<br />
23s (11,3)<br />
65-74 284 (13,7)<br />
75 and older 217 (10,5)<br />
Total 2072 (100%)<br />
644 (37,1 )<br />
48 ( 2,8)<br />
135 ( 7,s)<br />
103 ( s,e)<br />
13r ( 7,5)<br />
107 ( 6,2)<br />
142 ( 8,2)<br />
1e3 (11,1)<br />
?34 (13,s)<br />
1737 (100%)<br />
1021 (2s,1)<br />
1S1 ( 3,4)<br />
s25 ( 7,S)<br />
376 ( 8,5)<br />
446 (10,1)<br />
427 ( S,7l<br />
532 (12,1)<br />
663 (15,0)<br />
481 (10,e)<br />
44e2 (1oo%)<br />
Table I shows more or less comparable age distributions<br />
for the two bicycle groups, while for the pedestrians<br />
more emphasis falls on the youngest and the oldest<br />
age-group.<br />
Table 2. Sex of 3 Casualty Groups (Abaolute Numbers<br />
and Percentages) 1989<br />
Male<br />
Female<br />
Total<br />
B-MV P-MV B-NMV<br />
1132 (54,6)<br />
e40 (4s,4)<br />
2072 (100%)<br />
969 (ss,8)<br />
768 (44,21<br />
2497 (56,5)<br />
1Szs (43,4)<br />
1737 (100%) 4422 (100%)<br />
The three groups have more or less the samc dislribution.<br />
Table 3. Average Number of Inlurles per Casualty for<br />
the 3 Casualty Groups<br />
B-MV .<br />
P-MV<br />
B-NMV<br />
2,0<br />
1,9<br />
1,4<br />
While there appears to be a comparablc number of<br />
injuries for thc two casualty groups colliding with motor<br />
vehicles, the average number of injuries for non-motor<br />
vehicle casualties is much lower.
This is the first sign that even though the three groups<br />
all contain hospitalized patients, thc rest-group of<br />
cyclists is less severely injured.<br />
Table 4. Discherge for the 3 Casually Groupe<br />
(Abaolute Numbere and Percentages) 1989<br />
Where<br />
Ditcharged B-MV P-MV<br />
Home 184 (88,9)<br />
To anorhgr hospital s7 ( 4,7)<br />
To a nursing home 36 ( 1,7)<br />
Died in hospital 97 ( 4,71<br />
Total<br />
2072 (1oo%)<br />
B.NMV<br />
1505 (86,6) 4198 (94,7)<br />
97 ( 5,6) rol ( 2,3)<br />
54 ( S,1) 86 ( 1,9)<br />
81 ( 4,7) 46 ( 1,0)<br />
1737 (1oo%) {{22 (roo%)<br />
While again the figures for the motor vehicle<br />
casualties are comparable, it can be seen that the nonmotor<br />
vehicle casualties show a far lower pcrcentage of<br />
fatalities in hospitals.<br />
Table 5. Length of Stey in Hospital for the 3 Casualty<br />
Groups (Absolute Numbere and percentage) 1989<br />
Sectlon 3: Technical Sessions<br />
injuries is less than 2, implying that a large number of<br />
casualties have no more than one coded injury.<br />
Though this may be contrary to the belicf that traffic<br />
casualtics are "multi-trauma" patients, it is in fact so for<br />
the majority of the hospitalized Dutch trattic casualties.<br />
Of course, as we know, the very small injurics, such a$<br />
bruises and other little wounds, arc underreported since<br />
they are far less severe than those injuries that caused<br />
hospitalization.<br />
To leiun about the difference, the two possible injury<br />
pictures are presented:<br />
a. based on the main injury diagnosis only,<br />
b. based on all coded injuries.<br />
Injuries in this paper are presented as injury patterns,<br />
being the distribution of (all) injuries per pilticnt over<br />
body regions.<br />
Seven body regions are distinguished and onc rest-<br />
Broup. The total number of injuries will therefore excccd<br />
thc number of casualties, unless only the main injury<br />
diagnosis is used.<br />
Table 6. Inlury Pattern Based on the Maln Infury<br />
Diagnosis<br />
Body region B-MV P-MV B-NMV<br />
Length of Stay<br />
in Hospital (dayr) B-MV P-MV B.NMV Head/skull/brain 1 01 3 (48,9) 668 (38,5)<br />
Neck 19 ( 0,9) 11(0,6)<br />
Thorax 104 ( 5,0) 6s ( 3,7)<br />
1 day 67 ( s,2)<br />
2-9 days 928 (44,8)<br />
10-19 days s64 (27,21<br />
20-29 days 217 (10,5)<br />
30-39 days 103 ( 5,0)<br />
40 or more dayB 193 ( S,3)<br />
7s ( 4,S)<br />
774 (44,61<br />
s68 (21,2)<br />
183 (10,5)<br />
104 ( 6,0)<br />
233 (13,4)<br />
191 ( 4,3)<br />
2406 (54,4)<br />
995 (22,5)<br />
4ss (10,4)<br />
147 ( 3,3)<br />
224 ( 5,1)<br />
Back/pelvis 158 ( 7,6)<br />
Abdomen 45 ( 2,2)<br />
Arms 147 | 7,11<br />
Legs 5SB (26,0)<br />
Other/unknown 48 ( 2,3)<br />
113 ( 6,5)<br />
51 ( 2,e)<br />
12s ( 7,2)<br />
652 (37,s)<br />
52 ( 3,0)<br />
Totsl no.<br />
Total 2072 (1oo%, 1737 (100%) 4422 (100%) ol injuries 2072 (r00%) 1737 (r00%)<br />
It appears that pedcstrians stay the lon8est. This is<br />
illustrated by the emphasis on the last ciltegory compiued<br />
to the other groups.<br />
The non-motor vehicle cyclist casualties are<br />
overreprescntcd in the first two groups (a stay of less<br />
than l0 days), illu$trating again their lowcr injury<br />
severity level.<br />
Injury Patterns<br />
The WHO-ICD system as applied in thc Netherlands<br />
allows for the coding of one -'main" injury and 8 other<br />
The overall injury picture therefore has to be based on<br />
9 possible injuries.<br />
However, since the first coded injury is called "main<br />
injury diagnosis" this is often uscd to represent the<br />
patients' injuries. Furthcrmore, as can bc sccn in tahle 3<br />
from thc previous paragraph, the average numbcr of<br />
1566 (35,4)<br />
21 ( 0,5)<br />
1oB ( 2,4)<br />
24s ( 5,5)<br />
144 ( 3,3)<br />
7e1 (16,3)<br />
1455 (32,9)<br />
162 ( 3,7)<br />
4422 (100%)<br />
Injuries to the head (including skull and brain) form<br />
the largest category for all casualty groups. However<br />
therc some distinct differences:<br />
Cyclists colliding with motor-vehicles show the<br />
highest number, cyclists not colliding with motorvchicles<br />
the lowest.<br />
This might partly explain the differences already<br />
mentioned with respect to injury severity aspects<br />
bctwcen the two groups, since brlin and skull injurics<br />
arc important indications of severe and fatal outcome of<br />
accidents.<br />
Leg injury is the second highest category for all<br />
Eroups.<br />
Pedestrians $how more of them lhan the other groups'<br />
Both for pcdcstrians and thc rest-group oI cyclists, leg<br />
injuries rank almost as high as head injuries.<br />
Another intcresting differencc between the groups is<br />
the relatively high proportion of arm injurics for the last<br />
category of casualties.<br />
65<br />
.'i<br />
F<br />
:li<br />
t<br />
5<br />
.t<br />
.<br />
;<br />
' i<br />
:
13th lnternetlonal rechnlcal conference on Experlmentet safery vehlcles<br />
Possibly, the emphasis in this group on falls from the<br />
bicycle is the reason behind this difference.<br />
Table 7. Infury Pettern Based on All Inlury Diagnoses<br />
Body region B-MV P.MV B-NMV<br />
Head/brain/skull 1 681 (40,9)<br />
Neck 44 ( 1,1)<br />
Thorax<br />
Baclvpefvis<br />
351 ( S,5)<br />
277 (6,71<br />
Abdomen<br />
Arms<br />
113 ( e,8)<br />
5S3 (13,0)<br />
Lsg$<br />
984 (24,0)<br />
Other/unknown 125 ( 3,0)<br />
1153 (S4,2)<br />
23 ( 0,7)<br />
221 ( 6,6)<br />
21e ( 6,s)<br />
r34 ( 4,0)<br />
418 (12,4)<br />
1048 (S2,1)<br />
120 ( s,6)<br />
222e (37,5)<br />
31 ( 0,5)<br />
1e1 ( 3,2)<br />
314 ( s,3)<br />
177 ( S,0)<br />
1058 (17,8)<br />
1681 (28,3)<br />
263 ( 4,4)<br />
Total no.<br />
ol Injurler 4108 (100%) $372 (r00%) 5944 (1oo%)<br />
Compared to the previous injury pattern (Table 6.)<br />
emphasis for all casualty groups is still on hcad injury.<br />
However while for the motor vchicle casualties (both<br />
cyclists and pedestrians), the relative proportion of head<br />
injury is lower than before, for the rest-group of cyclists<br />
the relative proportion is somewhat higher. In the first<br />
two casualty groups we $ee considcrably higher proportions<br />
of arm injuries, while the proportion of leg injuries<br />
is smaller.<br />
Age Differences<br />
As we know, age has an important influence on the<br />
outcome of accidents.<br />
Therefore the previous injury patterns (based on the<br />
main injury diagnosis only) will be prcsented for<br />
different age groups.<br />
Table 8. Hslation Between Age-Group and InJury<br />
Pettern<br />
for the B-MV Casualties<br />
Body region<br />
Head/brain/skull<br />
Neck<br />
Thorax<br />
Baclt/pelvia<br />
Abdomen<br />
Arms<br />
Legs<br />
Other/unknown<br />
Total no of injuries:<br />
Age group (y€ars)<br />
0- 14 15-s4 55+<br />
57,S<br />
0,5<br />
1,0<br />
3,2<br />
3,4<br />
6,1<br />
26,2<br />
1,7<br />
51,2<br />
1,1<br />
5,0<br />
7,4<br />
2,7<br />
7,3<br />
22,8<br />
2,5<br />
41,0<br />
1,0<br />
7,3<br />
10,3<br />
0,8<br />
7,5<br />
29,8<br />
2,4<br />
408 (100%) 928 (100o/") 7s6 (100%)<br />
We see some relevant age differences for the head<br />
injuries, thorax injuries, abdominal injuries, back/pclvis<br />
injuries, and leg injuries.<br />
While head injuries and abdominal injuries show a<br />
sharp decline with rising age, the other body regions<br />
66<br />
show sharp rises. Only leg injuries appear to be lowest<br />
for the "middle age" group.<br />
Table 9. Relation Between Age group and InJury<br />
Pattern<br />
for the P-MV Casualty Group<br />
Body region<br />
Head/brain/skull<br />
Neck<br />
Thorax<br />
Back/pelvis<br />
Abdomen<br />
Arms<br />
Legs<br />
Other/unknown<br />
Ag€ group (years)<br />
0-14 15,54 55+<br />
48,6<br />
0,3<br />
1,9<br />
3,2<br />
4,3<br />
4,2<br />
35,9<br />
1.6<br />
33,9<br />
0,9<br />
4,2<br />
7,6<br />
3,5<br />
8,7<br />
38,0<br />
3,1<br />
31,6<br />
o,7<br />
5,3<br />
9,1<br />
0,9<br />
9,1<br />
38,8<br />
4,4<br />
Tolal no. of Inlurlea 626(100%) 5{2(100%) 589(100%)<br />
More or less the same picture appears as for the<br />
cyclists casualties. An important shift appears in thc two<br />
oldest groups: their relative proportions of leg injuries<br />
have become the highest separate groups, even exceeding<br />
head injuries.<br />
Table 10. Helation Between Age Group and Inlury<br />
Pattern for the B-NMV Casualty Group<br />
Body region<br />
Head/brain/skull<br />
Neck<br />
Thorax<br />
Back/pelvie<br />
Abdomen<br />
Arms<br />
Legs<br />
Other/unknown<br />
Tolal no. of injurie*<br />
46,3<br />
0,1<br />
0,8<br />
3,6<br />
7,6<br />
17,4<br />
20,0<br />
4,4<br />
Age group (years)<br />
15-54 55+<br />
45,4<br />
0,9<br />
2,7<br />
3,6<br />
2,9<br />
19,0<br />
22,2<br />
3,3<br />
18,6<br />
0,2<br />
3,1<br />
8,7<br />
1,3<br />
1e,8<br />
51,7<br />
3,6<br />
s27(100%) 1819(100%) 1676(10006)<br />
Again we see the same tendencies as for the other<br />
casualty groups. However there is a spectacular n1e<br />
influcnce as far as both head injuries and lcg injuries are<br />
concerned. The oldest age group show a totally different<br />
picture from the rest. The amount of leg injuries for the<br />
oldest age group is a factor ?.5 higher than for the<br />
younger groups, while the amount of head injury is<br />
comparably lower. This phenomcnon has been reported<br />
before (van Kampen, 1989).<br />
This injury picture thercfore is totally different from<br />
the prcvious ones.<br />
Here again we find evidence that the injuries resulting<br />
from motor-vehicle collisions are different from the ones<br />
resulting from the non-motor vehicle collisions.
Clearly, within the bicycle population there are<br />
different needs for protection against collision forces.<br />
Conclusions and Recommendations<br />
There are several sets of conclusions to be drawn and<br />
recommendations to he made:<br />
1. About the underreporting of accidents and casualties<br />
2. About the injury problem in general and the need of<br />
protcction<br />
3. About specific problems such as age and the need of<br />
protection.<br />
Ad l. Undeneporting of accidents and casualties in<br />
official accident statistics may ciluse those involved in<br />
policy making and establishing priorities to make<br />
incorrect decisions. This has happencd irlrcady since the<br />
main focus regarding cyclists is dcfinitely on casualties<br />
from motor vchicle accidents.<br />
It now appears that thc problem of the non-motor<br />
vehiclc bicycle accidents is far morc important than for<br />
any other separate group of road user, at least in<br />
numbers.<br />
As far as severity of the problem is concerned, it<br />
appears that this group is less severely injured than those<br />
rcsulting from motor-vehiclc collisions. However their<br />
apparent need for treatment in hospitals warrants far<br />
more public attention.<br />
So in the first place improvement of the level of<br />
registration of this type of accidents is needed. In the<br />
second place more priority should bc givcn tot accident<br />
prevention and injury prevention of this group of<br />
cyclists.<br />
The amount of detail in the data source used for this<br />
paper, national hospital data, is however not sufficicnt to<br />
point right to the optimal way of injury preventive<br />
measures at this time. The casualty group is a mixture of<br />
those who collided with other road users (non-motor<br />
vehicles!) and those who did not, with emphasis on falls.<br />
Therefore it is recommended to develop a study design<br />
to gather morc knowledge about the different cate8ories<br />
within this category<br />
st-0-08<br />
The Cause of Head Injuries in Real World Crashes<br />
Pete Thomas<br />
Mo Bradford<br />
Edmund \{ard<br />
Research Institute for Consumer Ergonomics<br />
Loughborough University of Technology<br />
Abstract<br />
European cars are buitt to conlorm to performance<br />
requirements that are intended to limit the hostility of<br />
various interior car components. However head injuries<br />
are frequently sustained by car occupants despite these<br />
Seetlon 3: T*hnlcal Sesslons<br />
Ad 2. The general injury problem of both cyclists and<br />
pedestrians, hit by motor vehicles and of the other<br />
cyclists, is such that there are at least two but probably<br />
three definite body arcfls in great need of protection: the<br />
head region (including skull and brain); the legs and the<br />
iilms.<br />
Since the problem does not only appear with regard to<br />
motor-vehicle collisions, the improvcment of car front<br />
end design can only be seetr as part of the solution,<br />
however necessary.<br />
In view of the very great numbcr of other casualties<br />
amongst cyclists, other injury-preventive measures have<br />
to be taken.<br />
In the Netherlands, recommcndations for the use of<br />
bicycle helmets are still fairly unpopular, both for policy<br />
makers and for the population at risk. Examples in other<br />
countries howevcr show possibilities and benefits of this<br />
type of solution.<br />
May the Dutch follow these examples! As far as arm<br />
and leg injury protection mcans are concerned we have<br />
still a long way to go.<br />
Ad 3. In view of the specific age problem reported in<br />
this paper, it can be concluded that at lcast oldcr pcople<br />
should not ride a bicycle without protccted lcgs and<br />
arms, and of course protected head.<br />
However, here again, the question of acceptability and<br />
available mcans oI protection arises.<br />
May reason win and may thcre become funds available<br />
for relevant measures and studies on the topic of proper<br />
solutions.<br />
References<br />
Harris. 1990. The Real Number of Road Traffic<br />
Accident Casualties in the Netherlands: A Year-Long<br />
Survey. In: Acc. Anal. & hev. Vol. ?2, No.4, pp. 371-<br />
378. 1990.<br />
van Kampen, 1989. Traffic Accidents of Elderly<br />
People in the Nethcrlandsi they really are more<br />
vulnerable than other road users. In: Procccdings of the<br />
Twelfth <strong>ESV</strong>-<strong>Conf</strong>erencc. Gothenburg, 1989.<br />
regulations. This paper examines the circumstances that<br />
result in these head injuries to both the survivors and the<br />
fatalilies. Restrained front seat occupants are analysed<br />
scparately from unrestrained rear seat occupants' AII<br />
directions of impact are included.<br />
AIS 3+ head injuries il's frequent amongst fatalitics<br />
although other body areas oftcn have injurics that are<br />
equally severe. Survivors sustain AIS 3+ injuries more<br />
often to other body areas thfln the head although thcy are<br />
less likely to have several AIS 3+ injuries.<br />
Glazing materials are highlightcd as a Yery common<br />
source of AIS I injuries while the roof, steering wheel<br />
67
lSth lntemetlonal Technlcel <strong>Conf</strong>erenae on Experlmental Satety vehlcles<br />
and pillars account for many of the more severe injuries.<br />
<strong>Int</strong>ruding structures are found to be commonly associated<br />
with the most severe injuries as arc contacts outside the<br />
vehicle. Head injuries are found to become morc scycre<br />
when the striking object supports the intruding structure.<br />
The value of restraint use by rear seat occupants is<br />
raised. The need for a better understanding of the role of<br />
intrusion and support from the striking object is stressed.<br />
<strong>Int</strong>roduction<br />
Much research is being performed in an effort to<br />
understand the factors surrounding the head injuries that<br />
occur in car crashes. The most frequent approach is to<br />
examine thc biomechanics of the injury to establish how<br />
the brain and cranium react to applied forces and how<br />
resulting movcment causes injury. Mucciardir, Nusholt2<br />
and Stalnaket' are cxamples. Many authors such as<br />
Warda and Tongi have proposed models of such injury<br />
causation. More recently Boock6, Thibault? and Meaneys<br />
have made considerable advances concerning the ccllular<br />
response of the brain to mechanical shock.<br />
There have been fewer studics that have examined the<br />
real-world crash conditions that result in head injuries.<br />
Vianoe stilted that real-world crash data is necessary to<br />
provide the impact situations resulting in head injury.<br />
Walficsh'0 when investigating the realism of a whole<br />
vehicle perpendicular barricr test identified thc stccring<br />
wheel as a major source of head injury amongst restrained<br />
drivers in frontal collisions. Bradfordrr found a<br />
similar result with UK data but also recognised contact<br />
with objects outside the car such as trees, other cars and<br />
trucks as causing more frequent severe brain injury.<br />
Thomasrz investigated injuries resulting from contact<br />
with the steering system and identified the stccring<br />
wheel as a frequent cause of the facc, head and torso<br />
injuries sustained by restrained drivers in frontal<br />
impacts. He noted that steering wheel intrusion was often<br />
associated with thcse injuries.<br />
Several authors have examincd the role of intruding<br />
structures as a factor in the causation of head injuries.<br />
Using CPIR and NCSS daia sets collected hetween 1972<br />
1979 Huelker3' 14' r5'16 examined the link between roof<br />
crush during a rollover and injury outcome. He concluded<br />
that there was no causal link between the amount of<br />
downward roof crush and AIS. He stated that any<br />
correlation was a result of relationships bctwccn vehicle<br />
impact severity and intrusion and vehicle impact severity<br />
and injury. This point has been amplified by Strother'7<br />
who, in a thorough analysis, systematically examined the<br />
velocity - timc curves of the events in side and roof<br />
impacts to show that injurics were sustained well bcfore<br />
the intrusion was completed. Most reccntly in an<br />
investigation of the cffcct of roof strength on injury<br />
mechanics in roll-ovcrs Bahlingr8 observed that the<br />
absence of roof deformation may benefit occupants if it<br />
results in belted occupants not striking the roof.<br />
68<br />
Enoyrere used a free flight hcadform impactor to<br />
measure thc deceleration on various interior parts of the<br />
car, he found typical values ranging betwccn 669 to 999<br />
for A-Pillar impacts and tiom 98g to l4lg for side<br />
header impacts. Monk?o used NASS and NCSS data to<br />
establish basic test conditions for a subsystem test to<br />
examinc the hazrud from lhc A-Pillar, front and side<br />
headcr rails. The tests wcrc based on the real-world<br />
crash severity as measured by dclta-V although no<br />
account was taken of any contact area dcformation that<br />
occurred prior to thc hcad impact.<br />
Analysis sample<br />
This analysis is based on a set of real-world accident<br />
data describing a section of the accidcnt UK population<br />
whose accidents havc becn examined within thc UK<br />
Coopcrative Crash lnjury Study. In-depth investigations<br />
of crashes in thc Midlands, the North-East and<br />
South-West areas of the UK have continucd since 1983.<br />
Accidents wcrc selected for investigation according to a<br />
strict sampling protocol which emphasised the number of<br />
the more sevcrc and fatal crashes. All accidents involved<br />
cars aged lcss than 6 years old at the time of the accident<br />
which were towed away from the accident site. The<br />
sampling system allowed the links to be drawn bctwcen<br />
the sample of accidcnts upon which this analysis is based<br />
flnd the population of accidents in the study catchment<br />
areas by the use of weighting factors.<br />
Crashed vehicles were examined at recovery garages<br />
in consideratrle detail including the points of occupirnt<br />
contact and the quilntity of crush and intrusion sustained.<br />
This data was supplemented by details ot the injuries of<br />
both fatalities and survivors and is subsequently coded<br />
using AIS-85. The data collection system have been<br />
described in morc dctail elsewhere.2''22<br />
Data presented in this paper are based on the<br />
unweighted accident samplc, the equivalent weighted<br />
values, when given, arc highlighted as population<br />
estimates. The sample describes the injurics of 60.59<br />
casualtics who were occupants of 3444 cars. The clata<br />
was collected betwccn 1983 and 1990. All 6059<br />
occupitnts werc travelling in cars within which someone<br />
was injured. The seating position and restraint use of all<br />
6059 casualties in the sample is shown in Table l.<br />
Table 1. Seating Position and Restraint Uee of All<br />
Occupants<br />
$oatins R.estmined UilrsuElnod RcflrArnt not Total<br />
trrdrt<br />
R.tr<br />
Not l$own<br />
3453<br />
69 0<br />
426<br />
995<br />
20<br />
1032<br />
59<br />
5<br />
49ll<br />
1123<br />
z5<br />
Tdrl 1\22 l44l 1096 6059
:._:t:. l<br />
The table shows that 3453 (E9Vo) of the 3879 fronr<br />
seat occupants for whom belt use was known were<br />
restrained, 995 (94Vo) of the rear seat occupants were<br />
unrestrained. To aid interpretation of this analysis onty<br />
these two groups were selected for further examination.<br />
Table 2 shows the direction of the impact that each<br />
occupant was involved in. The impact referred to is the<br />
one in which the casualty sustained the most severe<br />
injuries. 2195 @4%') of the restrained front seat<br />
occupants were involved in frontal collisions with a<br />
further 759 (22t/o)<br />
in side impacts.<br />
Table 2. lmpect Dlrectlon of Each Group of Casuatties<br />
Imp{ct Diftctim R63tseirtGd Frcot ScEl<br />
l'bcrront<br />
Fmnt<br />
Stnrck-sid!<br />
NorlShrck-fidc<br />
R.f<br />
Rollova<br />
zr95 (64%)<br />
# (14*)<br />
(E%)<br />
loE (3%)<br />
381 (lleb)<br />
UEsEained Rffi Scst<br />
534 (54fr)<br />
ll3 (ll%)<br />
E5 (9%)<br />
4r (4%)<br />
lE3 (18*)<br />
Tdrl 3453 fl00%) 905 f(n r<br />
2265 (65Vo) of the restrained front seat occupants were<br />
travelling in vehicles which were involved in only one<br />
impact, 977 (2880) suffered 2 impacts ro the vehicle<br />
although in many cases the second impact wa$ not<br />
$evere. 585 (597o) of the unrestrained occupants were in<br />
cars which only suffcred one impact and a furthcr 345<br />
(357a) suffered two impacts.<br />
Occupant data in this spread of impact types was<br />
analysed to givc an overview of the pattern ot injury in<br />
the complete range of contact areas. A concentration on<br />
particular impact types such as frontal or side impacts<br />
can underestimate the frequency of some contact areas.<br />
For example an impact which results in a driver sustaining<br />
a head contact with an A-Pillar might be classified<br />
as a frontal impact under some conditions and a side<br />
impact under other conditions.<br />
Data Analysis<br />
Pattern of injuries<br />
In this analysis the head is defined as the brain,<br />
cranium and soft surface tissues of the head excluding<br />
the forehead, it does not include the facial structures.<br />
: i' Sectlon 3: Ter'hnlcal Sesslons<br />
The term AIS 3+ injuries refers to injuries of a severity<br />
equal to or greater than AIS 3. Table 3 shows the<br />
severity of all injurics suslained by all the 3453<br />
restrained front seat occupants in the sample. In Table 3<br />
the AIS level represents the most severe injury in each<br />
body area.<br />
Within the grcup of restrained front $eat occupants the<br />
legs most commonly sustained injuries of any severity.<br />
1592 (46Vo) occupants sustaincd such an injury. The<br />
head ranked fifth in frequency behind the legs, chest,<br />
arms and face. 919 (27Vo) of thc 3453 occupants in the<br />
samplc sustaincd a head injury. However 307 (337o) of<br />
these 919 occupants with head injuries were AIS I<br />
representing cuts, abrasions and bruises or minor brain<br />
injury. Leg injuries, including injurics to the pelvis, were<br />
even more frequently minor. l02ft (657a) of the 1592 leg<br />
injuries were AIS I. However this figure is influenced by<br />
the coding protocol which allocated abdominal bruising,<br />
typicrlly from a seatbelt, as lying in the pelvis and<br />
therefore the leg area.<br />
An injury with an AIS score of 3 or above represents<br />
the onset of a significant threat to life, it repre.scnl.s for<br />
example a comminutcd tibia fracture or a cercbral<br />
contusi()n for example. Table 4 shows the rank in order<br />
of frequency of injury to cach of the body regions. The<br />
most commonly injured body region ranks first and the<br />
least commonly injurcd ranks last. The second column<br />
shows the rank order for injurics of all levels of severity,<br />
the third for injuries of AIS 3+ of casualties who<br />
survived and the fourth shows the AIS 3+ iniuries of<br />
those who died.<br />
Table 4. Pattern of Infuries-34s3 Hestrained Front $eat<br />
Occupants<br />
M6tCffi<br />
2.<br />
3<br />
{ E<br />
6 I<br />
Tdl<br />
OccuMb<br />
RinLffifi Nd dti A-El+<br />
hiuw<br />
Table 3. Frequency of InJury to Each Body Area-3453 Rsstrained Front S€at Occupants<br />
AI53+ Inlurltr df<br />
Suruivors<br />
AIS3+ Inlurte of<br />
Fstiliti.{<br />
tett<br />
trEg (43fr) ClHt (82%)<br />
Chrd<br />
Aru<br />
({3*)<br />
(42fr1<br />
ClHt<br />
Hed<br />
(27%,<br />
(25%l<br />
Hsd<br />
Abdoffi<br />
(67%l<br />
(37rol<br />
F.ft<br />
(35%) Atu<br />
(18%) trgs (33%)<br />
Heed<br />
Abdoffi<br />
Sprne<br />
(27%l<br />
(24 )<br />
(21*)<br />
ADdoffi<br />
SFfiE<br />
Fre<br />
(5%)<br />
(s%)<br />
(4%)<br />
Spine<br />
Am<br />
Fsce<br />
(r5%)<br />
(12%)<br />
(11%)<br />
3453 $2 90<br />
AIS I{cad (%) Fm+(%) Spine (%) Chest (%) Abdomen (%) Arms(%) Legs (Vo)<br />
0<br />
I<br />
2<br />
3<br />
4<br />
5<br />
6<br />
NA<br />
ls3/'<br />
307<br />
tl04<br />
84<br />
49<br />
49<br />
26<br />
73<br />
9<br />
12<br />
2<br />
I<br />
I<br />
I<br />
22ffi 66<br />
976 28<br />
178 5<br />
27 I<br />
6 0.2<br />
2729<br />
604<br />
77<br />
25<br />
I<br />
5<br />
12<br />
79<br />
t7<br />
2<br />
I<br />
0<br />
0.1<br />
0.3<br />
l96t<br />
990<br />
250<br />
8E<br />
79<br />
45<br />
3l<br />
57<br />
29<br />
7<br />
3<br />
2<br />
I<br />
I<br />
?j'30<br />
669<br />
65<br />
25<br />
27<br />
76<br />
19<br />
2<br />
I<br />
I<br />
I<br />
20{D<br />
lo28<br />
335<br />
-:<br />
58<br />
30<br />
l0<br />
2<br />
1861 54<br />
I 165 34<br />
222 6<br />
202 6<br />
0.r i<br />
I<br />
Total 3453 (100%) 3453 (100%) 3453 (100%) 3453 (100%) 3453 (1009o)3453 (100%)3453 (100%)<br />
I-t
lSth <strong>Int</strong>ematlonel Technlcal Conlerence on Experlmental Sefety Vehlcles<br />
Table 4 shows that the patterns of injury vary<br />
substantially depending on the severity of the injuries<br />
involved. When minor, AIS I injuries are included 467o<br />
ofall restrained front seat occupants sustain a leg injury,<br />
and the legs are the most frequently injured body region.<br />
The chest and arms have similar frequencies of injury<br />
and the head ranks fifth.ZTVo of all restrained front seat<br />
occupants sustain head injuries.<br />
When the less severe injuries are excluded and only<br />
AIS 3+ injurics examined the pattern of injurics changes.<br />
The survivors still have thc legs as their most frequently<br />
injured body region, 43olo sustaining an AIS 3+ injury'<br />
The head ranks third behind the chest with 257o of all<br />
restraincd lront seat occupants sustaining an AIS 3+ head<br />
injury. The Abbreviated Injury Scale is not the most<br />
appropriate measure for rating the importancc of the<br />
injuries of survivors. AIS is primarily a mcasure of<br />
threat to litc but for thosc who do not dic other issues<br />
such as long term disability and the amount of hospital<br />
in-patient treatment may be more significant. For this<br />
reason it should not bc concluded that the head injurics<br />
of survivors are insignificant, it is possible for AIS 3+<br />
injurics to result in loss of mental ability and behaviour<br />
changes. In the absence of appropriate measurcment<br />
scales it is not possible to make a clear comparison with<br />
other body regions.<br />
The pattern of injuries amongst the restraincd fiont<br />
seat occupants who die is quite different. 82To of all<br />
fatalities sustain an AIS 3+ injury to their chest and 6270<br />
to their head. Thesc are the most common two injured<br />
body regions. Leg injuries rank fourth after ahdominal<br />
injuries.<br />
Table 5 summariscs the pattern of injuries for the<br />
group of 995 unrestraincd rear seat occupants. Despitc<br />
the diflcrent seating cnvironment and occupant<br />
kinematics the distribution of injuries is similar in many<br />
ways to that of restrained front seat occupants.<br />
Teble 5. Pattern ol Inlurles-g9s Unrestrained Rear Seat<br />
Occupants<br />
M6tCffi<br />
3<br />
{ 5<br />
5<br />
7<br />
Tc'trl<br />
Oeuuntr<br />
Rrnlfutr No wtth AISI+ AIfXI+ In urler ot<br />
5urvtffi<br />
trgt 4%<br />
Fae fi%<br />
Altr 35%<br />
Hmd 32%<br />
ClEt 16%<br />
AbdoM 13%<br />
Splne 12fr<br />
IrE 37<br />
HHd 2E%<br />
Clst t4fi<br />
Affi 1l%<br />
Splne 5&<br />
F#e 4%<br />
Abdom 4%<br />
AISS+ <strong>Int</strong>uds of<br />
Fatalitie8<br />
Hefd /8%<br />
Ch6t nft<br />
Abdffi X5%<br />
trBs 28%<br />
gpine E%<br />
Face 13%<br />
Ams<br />
g%<br />
vts 8r ,o<br />
Whcn AIS I injuries are included 32Vo of all unrestraincd<br />
occupants sustain head injuries and the head<br />
ranks fourth after the legs, face and arms. The head still<br />
ranks after the legs as the second most comm()n site of<br />
the AIS 3+ injuries of survivors. However 7870 of those<br />
within this group who die sustain AIS 3+ injuries to their<br />
70<br />
. :<br />
head and the head ranks equal first with the chest as the<br />
most common site of AIS 3+ injurics.<br />
The distribution of thesc head injuries amongst the<br />
groups of restrained front and unrestrained rcar seat<br />
occupants selected for further analysis is summariscd in<br />
Table 6.<br />
Table 6. Head Inluries of Restrained Front and<br />
Unrestrained Rear Seat OccuPants<br />
Head Injury<br />
Sevpritv<br />
AIS 0 (Uninjurcd)<br />
AIS I<br />
AIS 2<br />
AIS 3+ Survivus<br />
AIS 3+ FataLitie,s<br />
Restrained Frcnt<br />
flccunnnts<br />
2534<br />
307<br />
404<br />
8l<br />
t27<br />
Unrestrahed Rear<br />
i-lccrrnonto<br />
581<br />
14l<br />
120<br />
22<br />
3l<br />
Total 3453 995<br />
The fatally injured casualties in both groups tended to<br />
sustain injuries that were more severe than thc survivors.<br />
Amongst the restraincd front $eat occupants th;re were<br />
Ll (l4To) of the 8l survivors who sustained AIS 5+<br />
injuries comparcd to 64 (50Vo) of the 127 fatalities for<br />
example.<br />
If a casualty has only one injury then the introduction<br />
of a measure to reduce injuries can make a large<br />
diffcrcnce. Converscly if a casualty has many injuries<br />
then a countermeasure that reduces just one may make<br />
little diffcrcnce to that casualty. The rangc of frcquencies<br />
of injury to each body area shown in Tablcs 4 and 5<br />
gives a measure of multiplicity of injury. When the<br />
tables show many body arcas to be frequently injured it<br />
is likely that occupants mily have severitl injurics' For<br />
example it 78Vo of unrestraitrcd fatalities sustain an AIS<br />
3+ head injury and 787o sustain AIS chest injury then if<br />
the injuries arc distributed randomly 78Vo x78Vo = 6lVo<br />
will havc both head and chcst AIS 3+ injuries. This is<br />
demonstrated tnore clcarly in Table 7 which shows the<br />
numbcr of body regions sustaining AIS 3+ injuries for<br />
thc groups of restraincd front and unrcstraincd rear seat<br />
occupants who survived and who died.<br />
Table 7. Multiplicity of AIS 3+ lnJuries<br />
NMbtr of Body<br />
RegifltB<br />
with AIS 3+<br />
I<br />
2<br />
3<br />
4<br />
5<br />
6<br />
R.csEained Front Scal<br />
fLrrrffiflu<br />
MAIS 3+ MAIS 3+ MAI$ 3+<br />
Suruivm<br />
5<br />
53<br />
l2<br />
2<br />
34<br />
63<br />
55<br />
w r0<br />
UtrstsEined Reff Scat<br />
tu.r|#nr.<br />
63<br />
0<br />
0 I<br />
MAIS 3+<br />
Fetnlities<br />
Toral OeuDutB 332 190 7r &<br />
MAIS 3+ injured<br />
h.dv Eeimi 1.25 ?sf, 2.ffi<br />
l0<br />
12<br />
6<br />
9<br />
2<br />
I
Table 7 shows that fatally injured occupants whether<br />
they are restrained front seat occupants or unrestrained<br />
rear seat occupants sustain an average of 2.6 AIS 3+<br />
injured body regions per person. 34 (187o) of the<br />
restrained front seat fatalities and l0 (25Vo) of the<br />
unrestrained rear $eat fatalities sustained only one AIS<br />
3+ injured body regions.<br />
In comparison the survivors tcndcd to havc fewer<br />
body regions with AIS 3+ injurics. The restrained lront<br />
scat occupants sustained 1.25 per person and the<br />
unrestrained rear seat occupants sustained l.l-5 pcr<br />
person. 265 (804o) of the front seat occupants and 63<br />
(89%) of the rear seat occupants sustained only one body<br />
region with AIS 3+ injury.<br />
If a countermeasurc was introduced and it had the<br />
effect of preventing AIS 3+ injuries to one body region<br />
it is unlikely that the numbcr of fatalities would dccrease<br />
much as most will havc other life-thrcatening injuries to<br />
other body areas. It would havc a grciltcr effcct amongst<br />
the groups of survivors who have fewer injurics and are<br />
unlikely to have others of AIS 3+. In most cases a<br />
package of countermea$ures will be nece$:rary to prevent<br />
fatalities.<br />
Causation of head injuries<br />
The contacts that resulted in the most severe head<br />
injury for each occupant wcre codcd and classified<br />
according to the general location. The 1233 occupants<br />
with a hcad injury sustained fl total oI 127 | contacts with<br />
identified objects and a further 316 with unknown<br />
objects. Some injuries werc a result of contact with two<br />
separate objccts, for exantplc a windscreen and an<br />
A-Pillar. both of these contacts would be shown in the<br />
following tables. Where an injury is a result of 2<br />
contacts no judgcment has been made as to which is the<br />
dominant factor.<br />
Contatt Location Of Reslrained Front Scat Occupants<br />
Table I shows the contacts that resulted in the injuries<br />
of the restrained front seat occupants which are<br />
illustrated in Figures I and 2.<br />
The single most frequent contact zone for those<br />
occupilnts whose most severe head injury was of AIS I<br />
was thc side glass. This area accountcd for 49 (197o) of<br />
thc 262 identified contacts. The combinod set of all<br />
glazing materials accountcd for 86 (33%) injuries. The<br />
roof and associatcd slructurcs accountcd lor 44 (l7Va) of<br />
the contacts and the steering wheel for 43 (l6Vo)<br />
contacts.<br />
The importance of the glazing contacts was lower<br />
amongst the AIS 2 injuries with the side window glass<br />
causing only 47 (ll%o) of the injuries. All glazing<br />
materials together accounted for 84 (2070) of all contacts<br />
ranking third. Mosi frequent were injuries arising from<br />
contact with the steering wheel (126 - 29o/o) followed by<br />
the pillars (61- 167o).<br />
<strong>Section</strong> 3: Technical Sessions<br />
Table 8. Locetlon of Head Contects of Restrained<br />
Front Seat Occupents<br />
LLlt<br />
Wi!frnil<br />
Sid. €b<br />
R{ClE<br />
tJnhEH Oil<br />
SHin8 WtFl<br />
FrU<br />
Rma<br />
Pilln<br />
Dfin<br />
Sfl!<br />
En rtt<br />
Oih.r vdklc<br />
O*r V.iicl. kEir<br />
TE,FoLJsp.tmd<br />
l:kktr<br />
Cnr$ing<br />
Odr<br />
I'{dIEr<br />
TSIMCtr!<br />
Tdi cons6<br />
Till t}[upsb<br />
Figure 1. <strong>Int</strong>erior Head Contacts ol Restralned Front Seat<br />
Occupants<br />
d@<br />
ffih;<br />
(.'l*<br />
J<br />
l-ffi1<br />
lil-,r rl<br />
l r<br />
I dEHl<br />
2 0s)<br />
J (2r)<br />
3 (lt)<br />
I (lt)<br />
(04)<br />
m (rs)<br />
lm<br />
AISdffiHd|Hr4urt<br />
l0 (1r) 13 (3%)<br />
.9 (r9*) 17 (lrm)<br />
0 (0!i) 0 ()*)<br />
27 (rW) 24 (6%)<br />
43 (16%) t2d (?gfr)<br />
5 (?*) 2l (5*)<br />
1,1 07s) 60 (14*)<br />
22 (896) 6? (16 )<br />
l? (5*) 16 (4t)<br />
It (7*) 20 (5S)<br />
262 Ofl,*)<br />
h2<br />
w<br />
I (2s)<br />
5 (l*)<br />
2 (0,5%)<br />
7 (i.5$)<br />
0 (0*)<br />
l2 (3%)<br />
159<br />
43r (rmr)<br />
590<br />
4+r<br />
5 (4S)<br />
2 (l%)<br />
0 (0fr)<br />
0 (0*)<br />
u3 (r7s)<br />
9 (7fi)<br />
8 (6fi)<br />
24 (r8*)<br />
l3 (r0%)<br />
2 (r*)<br />
lt o?t)<br />
2 (tS)<br />
I (7 1<br />
r (6ft)<br />
0 (ofi)<br />
7 (fi)<br />
2 6 .<br />
135 (lm*)<br />
l6t<br />
l7 (4*)<br />
1 (?fi't<br />
3 (t%)<br />
2 (0r)<br />
55 (r? )<br />
E (l%)<br />
9l (21%)<br />
7l il6*)<br />
2J (6S)<br />
I (2*',<br />
73 (l6s)<br />
?t (5%)<br />
40 (9%)<br />
2 (0r,)<br />
0 (0*)<br />
14 Gt)<br />
3 l -<br />
WF<br />
l-<br />
[,<br />
F.r _ r.rl<br />
I r x * s l<br />
i'" Ht<br />
I<br />
Figure 2. Exterlor Head Contacts of Restrained Front Seat<br />
Occupants<br />
The most common single zone causing AIS 3+ injuries<br />
to surviving restrained front scat occupants was the<br />
pillars accounting fnr 24 (187o) injuries. The steering<br />
wheel was contacted by 23 (l7o/o) casualties as was the<br />
striking vchiclc. Together objects outside the car werc<br />
associated with 42 (llEa) of these injuries.<br />
The most severe injuries were those to thc fatalities<br />
coded with AIS values between 3 and 6. Thc most<br />
tl<br />
443 000fr)<br />
414<br />
tx1<br />
7l<br />
'1<br />
; 3<br />
il
13th lnternetlonal Technlcal Gonterence on Experlmentel Setety Vehicles<br />
common single contact was with the roof of the car, 9l<br />
(LlVo) of the 443 known contacts were in this area- Head<br />
contact on a striking vehicle in the impact was associated<br />
with 73 (l6Vo) of the injuries followed by the pillars<br />
with 7l (L6Vo) of thc contacts. When all objects outside<br />
the car were groupcd togethcr they were associated with<br />
136 (3IVo) of the head injuries of this group of fatal<br />
occupants. The stecring wheel was associated with 55<br />
(l2To) of these injuries.<br />
The involvement of objects outside the car was found<br />
to increase in frequcncy as the severity of the resulting<br />
injuries increased. At the level of AIS I thcse objects<br />
accounted for only 12 (SVo) contacts rising to a total of<br />
42 (\lVo) amongst the survivors with AIS 3+ injuries and<br />
136 (317o) amongst the fatalities.<br />
Conlact Location Of (Jnrestrained Rear Seal Occuptants<br />
The contact locations of the head injuries of the<br />
unrestrained rear scat occupants are shown in Table 9<br />
and illustrated in Figures 3 and 4.<br />
Table 9. Location of Head Contac.ts of Unrestrained<br />
R6Er Seat Occupants<br />
IrEfu<br />
Windffi<br />
Si{t Olrs<br />
Rs Cbs<br />
Unt|YM Glss<br />
SHidB WlEcl<br />
Fsir<br />
Rd{<br />
Fille<br />
Dfiar<br />
ss<br />
Figure 3. <strong>Int</strong>erior Head Contacts ol Unrestrained<br />
Rear Seat Occupants<br />
72<br />
Cmstl#$s AI5 of mt rcvee hsd hjE<br />
ATS I AIS 2 AIS 1+ Faditu<br />
Efflor<br />
orhs vd*<br />
(hn Vqhich kHtr<br />
tuPoleJsp,Pil<br />
CtuErHitr<br />
Crurhing<br />
O|li<br />
l$axm<br />
TslKmmCmHh<br />
TMI Conrb<br />
Tdd oftup$B<br />
6 (5%)<br />
I Gft)<br />
3 (3s)<br />
I (rs)<br />
0 (0%)<br />
0 (0%)<br />
2J (231b)<br />
13 (r2%)<br />
5 (5*)<br />
?t (25%)<br />
o (0s)<br />
0 (ffi)<br />
I (8%)<br />
0 (0n)<br />
0 (0fi)<br />
3 (3s)<br />
J 5 .<br />
lm (rm%)<br />
165<br />
14l<br />
7 (5%'<br />
23 (r7 l<br />
0 (0*)<br />
2 (l%)<br />
0 (0%)<br />
? (t%)<br />
32 eAJ<br />
12 (9#)<br />
lt (t*)<br />
23 (17*)<br />
0 (04)<br />
0 (ffi)<br />
m fls%)<br />
0 (0%)<br />
0 (0*)<br />
3 (2%)<br />
61<br />
-<br />
135 (rm%)<br />
NI<br />
120<br />
0 (ffi)<br />
5 (r3ft)<br />
0 (0*)<br />
0 (0n)<br />
0 (04)<br />
2 (5S)<br />
lt (28ft)<br />
rt (21%)<br />
I (3%)<br />
4 (rorb)<br />
o (0*)<br />
o (0*)<br />
5 (r3ft)<br />
0 (0%)<br />
0 (0*)<br />
3<br />
(8s)<br />
8 .<br />
39 (lm%)<br />
41<br />
0 (0*)<br />
0<br />
0<br />
0<br />
0<br />
5<br />
I<br />
(0%)<br />
(0s)<br />
(0%)<br />
(04)<br />
(6ft)<br />
(10%)<br />
m<br />
5<br />
0<br />
Q6%',<br />
(6%)<br />
(0%)<br />
r (6%)<br />
0 (ofr)<br />
27 (35%)<br />
5 (6%)<br />
3 (4*)<br />
0<br />
(0s)<br />
?8 (100%)<br />
rm<br />
@<br />
t-- ffi_l<br />
FT'qll<br />
ffi<br />
[ffi<br />
I r r e $ l<br />
t d l t d d d<br />
Figure 4. Exterlor Head Contacts of Unrestrained Rear<br />
Seat Occupants<br />
These occupants showed some differences in the<br />
sources of their head injuries. The most frequent sources<br />
of AIS I head injuries were the front seats and the roof<br />
structures accounting for 28 (25To) and 2.5 (23Vo) of<br />
contacts respectively. Glazing materials were associated<br />
with a total of 23 (?.48o) of injuries.<br />
The most common source of the AIS 2 head injuries<br />
was thc roof being associared with 32 (24s/o) of the<br />
injuries. The front seats and the side glass each<br />
accounted for 23 (177o) oI the injuries. Altogether<br />
glazing materials caused 32 (23Vo) of the AIS 2 injuries.<br />
Head contact on off-road objects such as trccs, lamp<br />
posts and thc ground accounted for 20 (157o) of thcsc<br />
injuries.<br />
The 22 surviving unrestrained reflr seat occupants who<br />
sustained AIS 3+ head injuries contircted 47 objects, 39<br />
of which were identified. The roof and pillars were most<br />
commonly struck accounting for l1 (2870) and I (2I%)<br />
of contacts.<br />
The fatally injured reilr seat occupants sustained 78<br />
known contacts. Trees, lamp posts, other poles and the<br />
ground together accounted tor 27 (35Vo) of the contacts.<br />
Altogcthcr cxtcrior objects comprised 40 (517a) of all<br />
contflcls. The pillars were the most comm(lnly contacted<br />
interior structure, accounling for 20 (267o) of all<br />
contacts.<br />
Proposals have been made in both Europe and the US<br />
to introduce measures aimed at nlitigating the hcad<br />
injuries resulting from contact with the header rails and<br />
pillars. The contact zonc labclled<br />
'-roof<br />
in Tables 8 and<br />
9 includes thcsc arcas and Tables l0 and I I show the<br />
contacts brokcn down in more detail. The perccnlagcs<br />
given are based on thc total number of contacts tor each<br />
injury scvcrity group within Tables 8 and 9.<br />
Table 10. Rool and Pillar Head Contacts of Hsstrained<br />
Front Seat Occupants<br />
Hsd lniN Scvedtt<br />
CmrtrrAH AIS I AIS2 AtS 1+ SuryiYffi AIS 3+ Pab.litis<br />
WA l{Hdtr<br />
Suvis<br />
Side H!f,dEr<br />
Gnb Hqdlc<br />
Rffif<br />
Su nmf<br />
A.Pillq<br />
B-Fillsr<br />
C.Pillrr<br />
Swivcl<br />
I<br />
t4<br />
4<br />
ta<br />
I<br />
8<br />
9<br />
0<br />
5<br />
TMI 66 {1396) ln tNt*\ 72(U*\ 162 (3?'fil<br />
4<br />
4<br />
ll<br />
0<br />
36 {<br />
E<br />
30<br />
6<br />
0<br />
0<br />
4<br />
0<br />
4<br />
0<br />
l0<br />
t0<br />
0<br />
I<br />
6<br />
0<br />
t3<br />
69<br />
0<br />
47<br />
r4 00
Tabb 11. Roof end Pillar Head Contacte of Unrestralned<br />
Resr Seat Occupants<br />
WS llddtu<br />
Sur Virfr<br />
Si& HrrdE<br />
cflD llrfillc<br />
nlr lfidE<br />
Ftrf<br />
Su Rmf<br />
A-Pill&<br />
B-Pllls<br />
C.Pilhr<br />
S*iwl<br />
tlrd Ir ry Scvsrty<br />
^Isl ATS 2 AIS 3+ S AIS it+ Fdlitis<br />
0<br />
I<br />
0<br />
0<br />
2<br />
m<br />
I<br />
5<br />
I<br />
4<br />
0<br />
0<br />
ll<br />
5<br />
I<br />
,1<br />
I<br />
0<br />
t<br />
3<br />
I<br />
I<br />
0<br />
3<br />
0<br />
0<br />
7<br />
0<br />
0<br />
5<br />
0<br />
3<br />
4<br />
0<br />
0<br />
0<br />
0<br />
I<br />
3<br />
0<br />
t3<br />
4<br />
3<br />
3t (35fr) 44 144*\ 19 (49*) 2t a16sr<br />
Table I showing the contacts of restrained front seat<br />
occupants revealed lhat therc wcrc 203 head contacts<br />
with the roof and its associated structures and 184 with<br />
the pillars. These 387 contact$ are shown in Table 10.<br />
The roof alone was associated with 69 of the contacts of<br />
the AIS 3+ fatalities, this represents 1670 of all of the<br />
443 head contacts sustained by this group. B-Pillar<br />
contacts were also frequent in this group. 57 (ll%o) of<br />
the 443 head contact$ were with B-Pillars. The side<br />
header rail was associated with only 13 (3Vo) of the<br />
contacts of the fatalities and 14 (SVo) of those wirh AIS<br />
t head injuries.<br />
There were a total of 76 roof contacts and 53 pillar<br />
contacts for unrestrained rear seat occupants shown in<br />
Table 9, thcsc are shown in detail in Table ll. The roof<br />
was a fiequent source of AIS I injuries accounting for<br />
lSVo of all contacts but it was only rarely associatcd with<br />
the AIS 3+ injuries of fatalities. More common sources<br />
of the most scvere head injuries were the B- and<br />
C-Pillars together accounting for l7 (227o) of atl the<br />
head contacts of the fatalities with AIS 3+ injuries.<br />
Although the side header rail was not associated with<br />
any of the contacts of those who died or those with AIS<br />
I injuries, it was associatcd with \Vo of the contacts of<br />
the remaining two groups.<br />
Ejeuion<br />
Table 9 showed that 5l7o of all of the hcad contacts of<br />
the fatally injured unrestrained rear seat occupants wcre<br />
with objects outside the car. It does not show whether<br />
this is a result of thc exlcrior object intruding into the<br />
vehicle or whether the occupants were ejected. Tabl0 l2<br />
shows the numhers of casualties with AIS 3+ iniures<br />
who were ejected from the car.<br />
Tebla t2. Elecillon From the Car-All Casuatties Wirh AIS<br />
3+ Heed Infuriee<br />
SflidB Posidm No El*tl,m fuddE|trrbo Cilpl# HdKlr(M<br />
ktrl.d F ilr<br />
8d<br />
Swivf,<br />
Fslditi6<br />
Ur#rlr.d l,.e<br />
S€f<br />
swiffi<br />
Fulitrx<br />
74 (96*)<br />
109 (91*)<br />
t9<br />
l?<br />
(gt)r$)<br />
(59%)<br />
2<br />
9<br />
0<br />
4<br />
(3S)<br />
(8%)<br />
(04)<br />
(t4fb)<br />
r o*)<br />
2 Qeo,<br />
2 00*)<br />
8 (26S)<br />
I<br />
7<br />
I<br />
2<br />
Sectlon 3: Technlcal Sessions<br />
Table 12 shows that ejection was rare amongst the<br />
restrained front scat occupants. 74 (967o) of the<br />
survivors and 109 (9lVo) of the faralirics with AIS 3+<br />
head injuries were not ejected. However 9 (87o) of the<br />
fatalities were partially ejected. 'fhe 7? surviving<br />
unrestrained rear scat occupilnts with AIS 3+ head<br />
injuries showed a similar pattern l9 (907o) remaining in<br />
the vehicle. The two who wcrc completely ejected<br />
however represented llVo of this group. Thc fatally<br />
injured rear seat occupflnts showed a markedly different<br />
pattern. Only 17 (59Vo) staycd within the vehicle, 4<br />
(l4Vo) were partially ejected and 8 (287o) completely<br />
ejected. Ejection from the vehicle is therefore an<br />
important factor for the group of unrestrained rcar seat<br />
occupants who die.<br />
Inrrusion<br />
Table I showed that amongst the group of restrained<br />
front seat occupants with AIS 3+ hcad injuries 42 (TlVo)<br />
of the survivors and 136 (3 l%o) of the fatalities sustained<br />
hcad contacts with objects outside thc car. The<br />
equivalent figures for the unrestrained rear seat<br />
occupants with AIS 3+ head injuries were 8 (217o) of the<br />
survivors and 40 (51%) of the filtalities. Table l0 shows<br />
that with the exception of the fafally injured unrestrained<br />
rear seat occupants ejection was rflre in both groups.<br />
Since the casualty's head is scldom ejected from the car<br />
to hit fln exterior object the alternative is that thc objcct<br />
entcrcd thc car interior. It is therefore useful to consider<br />
the role of intrusion in injury causation.<br />
Up to two contacts were coded for each injury, if all<br />
were with objects inside the car they are classified as<br />
interior, if all arc with objects outside lhe car the<br />
contacts are classificd as cxterior. Some occupants<br />
contacted two objects, one inside and one outsidc thc<br />
car, these are classified as mixed contacts.<br />
It was suspcctcd that the location of the striking object<br />
with respect to the contact point might influence the<br />
injury outcome. Some contacts were wilh a part of the<br />
car which exhibited residual intrusion. If the striking<br />
object was not immcdiatcly bchind the contact point, the<br />
intrusion was classified as unsupported intrusion. If the<br />
striking object was immediately behind the contact area<br />
this was classificd as supported intrusion. These<br />
classifications arc illustratcd in Figure 5.<br />
Table l3 shows the location of the head contact area<br />
and the nature of thc intrusion corresponding to the<br />
contacts causing the most severe head injuries sustained<br />
by each casualty. All casuirlties in the tatrle are<br />
restrained front scat occupants who were not ejected<br />
from the ciu.<br />
Table l3 shows that as hcad injurics become more<br />
severe the incidencc of intrusion and of exterior object<br />
contact grows. 178 (96%) of the car occupilnts with only<br />
an AIS I head injury sustain thcir injuries from striking<br />
interior contacts alone. 50 (2'lVo) were with intruding<br />
T<br />
:!<br />
:ii<br />
j:<br />
l*
13th lnternetlonal Technlcal <strong>Conf</strong>erence on Experlmental Salety Vehlcles<br />
Tabh 13. Head Contact Locetion,<strong>Int</strong>ruslon and Influence<br />
ol Exterlor Oblects-tton-elected Restrained Front fuat<br />
Occupents<br />
hEbCilffi<br />
Cflffir l#{df, AIX df Md Savd Hd TnhN<br />
ErLrlor Cdt*b<br />
Ml$d Colrct<br />
Urbonr Cod.t<br />
ltu<strong>Int</strong>uifl<br />
<strong>Int</strong>uiffi<br />
<strong>Int</strong>uiflN,4{<br />
Subbbl<br />
Mhtum<br />
Irruim<br />
SrDtotrl<br />
Holrtuim<br />
Irtuim<br />
<strong>Int</strong>uimN/K<br />
Subtotrl<br />
Srbtoarl<br />
AIS I AIS ? AIS 3+ AIS 3+<br />
125 (68*)<br />
50 (27fr)<br />
3 (2!6)<br />
u6 (96m)<br />
0 (0*)<br />
4 (2s)<br />
4 (l*)<br />
l (ls)<br />
2 (ls)<br />
0 (0*)<br />
3 (t*)<br />
l0a<br />
9r (3?S)<br />
139 (56m)<br />
6 (2*)<br />
r3r (95r)<br />
r,!t<br />
0 (04)<br />
6 (2r)<br />
a ofr)<br />
0 (0m)<br />
6 (3s)<br />
| (0*)<br />
7 (3*l<br />
10 (18*)<br />
z7 (Atfr't<br />
0 (04)<br />
37 (66m)<br />
2 (1*\<br />
lJ (27S)<br />
u 60fr)<br />
l (zft)<br />
l (zft)<br />
0 (0*)<br />
t (de6)<br />
I t .<br />
5 (5s)<br />
5r (r7%)<br />
7 (24)<br />
65 (64ft)<br />
3 (3*)<br />
28 (28S)<br />
rr (3rm)<br />
0 (0%)<br />
5 (5%)<br />
0 (0%)<br />
5 (5*)<br />
t -<br />
No Inhrrrlon<br />
unenrpportcd<br />
rntnreton<br />
-,\<br />
f-<br />
( k ; \ /-<br />
t A I<br />
\t/a/t**-l<br />
/<br />
,{ [. lffi#l<br />
l\l I<br />
/ l \ |<br />
Supportcd <strong>Int</strong>rudon<br />
Figure 5. Unsupported and Supported lntrusion<br />
contact areas. This was reduced to 37 (66Vo) survivors<br />
who sustained an AIS 3+ hcad injury and 65 (65Vo)<br />
filtillities. 3l (3Lvo\ of the fatalities sustained their head<br />
injuries from striking intruding objects alone.<br />
Contact with extcrior objccts alone resulted in just 4<br />
(ZVo) of thc AIS I injuries but with l7 (30o/o) of the AIS<br />
3+ injuries of survivors and 31 (3lo/o) of the AIS 3+<br />
injuries of the fatalities.<br />
<strong>Int</strong>rusion, meaning the reduction in interior spacc of<br />
the vehicle is a measure of thc rcsponsc o[ the vehicle<br />
structurc to the forces applied. As such it might be<br />
expected to be purely related to some mcasurc of impact<br />
sevcrity. The link between head injury severity and<br />
intrusion might therefore be a manifestation of the link<br />
between intrusion and impact sevcrity. The correlations<br />
between the measures were examined using chi-squared<br />
tests. The head injury severity of the restrained front seat<br />
occupants was found to correlate with thc prcscnce of<br />
intrusion, thc prcscncc of supported intrusion, the<br />
amount of intrusion and the delta-V of thc impact to the<br />
vehicle. All lhese correlalions were at a level better than<br />
74<br />
0.1%. It can not be concluded therefore that intrusion is<br />
a causal factor for head injury.<br />
Tablc 14 shows the support by exterior objects of the<br />
intruding interior contacts, the percentages are based on<br />
the column totals in Table 13. Support was not common<br />
amongst the group of casualties sustaining only AIS I<br />
injuries. 20 (ll9o) of the contacts were intruding and<br />
supported. 9 (l6vo) of the group of survivors sustaining<br />
AIS 3+ head injuries contacted supported intruding<br />
structures as did 4 I (4I7o) of the fatalities. The variation<br />
of head injury severity with support lrom exlerior objects<br />
is significant at a level better than 0.17o when tested<br />
using a chi-squared test.<br />
Table 14. Nature of Support ol lntruding <strong>Int</strong>erior Head<br />
Contacts<br />
$wpilt AIS df MNI Scm Hed IniN<br />
AIS I Ars 2 AIS 3+ AIS 3+<br />
UBuFpfftod <strong>Int</strong>uim<br />
Suprortcd lnmsim<br />
30 (16*)<br />
2p (il96)<br />
100 (10%)<br />
39 (16%)<br />
l8 (32*)<br />
e 06*)<br />
r7 (r7 )<br />
4l (41%)<br />
lqq t{64\ 27 (44*,\ 58 a584,l<br />
Safety Regulations<br />
Head protection for car occupants is legislatively<br />
centred around the use of a standard headform impact<br />
tcst in which a 7 Kg headform impacts various parts of<br />
the car at a velocity of 24 k/hr. The dccclcration is<br />
Iimitcd to a value of 80g for 3ms. The Europcan<br />
requirements are contained cilhcr within ECE regulations<br />
or similar EC directives. The 80g for 3ms limit is based<br />
upon the tolerance curve for head injury dcvclopcd at<br />
Wayne State University which defines combinations of<br />
deceleration and duration of head impulscs that form the<br />
boundary below minor concussive injury. ECE 21<br />
contains spccifications for this test and in general<br />
requircs thc facia, grab handles, sun visors and the rear<br />
facc o[ thc lront seats to comply. Regulation 21 employs<br />
a hcadlorm lo identify potential head contacts in a zone<br />
dcfincd by thc use of a device thilt pivots about an arc<br />
betwcen 736 mm and 840 mm. Objects within this zone,<br />
cxcluding the steering wheel and the pillirrs iue required<br />
to comply with thc headform test as do shelves and the<br />
rear of the front seats. Head restraints and front seats are<br />
covered more specifically within ECE t7 which again<br />
requires the headtorm impact to bc pcrformcd. ECE l2<br />
covcring steering system performance contains atr option<br />
for the headform impact to be performed as an<br />
alternative to the torso bodyblock impact although car<br />
manufacturcrs rarcly choose this test.<br />
The roof and the pillus are merely required to have a<br />
minimum radius of curvature or a limited downward<br />
projection.<br />
The US regulations are broadly similar to the<br />
European regulations although FMVSS 201, which<br />
covers interior fittings, contains slightly larger areas<br />
exempted from its requirements.
Despite the intention of the rtgulations this analysis<br />
has shown that car occupants frequently sustain head<br />
injuries in crashes rcgardless of restraint usc and that<br />
thcse injuries can be sevcre. While head injuries may not<br />
always be the most frcquent when all levels o[ severity<br />
are considered they are very common flmongst the more<br />
severcly injured casualtics. Because survivors who<br />
sustain AIs 3+ injuries havc a relatively low multiplicity<br />
of AIS 3+ injury the prevention of head injuries might be<br />
expected to benefit this group more than other groups.<br />
Fatalities who sustain AIS 3+ injuries have on average<br />
2.6 body areas injured at this scverity. Although 677o<br />
have such an injury to their head it is likely that the<br />
prevention of head injuries will leave other life<br />
threatening injuries remainin g.<br />
The parts of the car interior that are subject to the<br />
hcadform test requiremcnts of the interior fittings<br />
regulation do not appear to be frequent sources of injury.<br />
The restrained front seat occupants who only sustained<br />
AIS I head injuries made I | (4Vo) of the contacts within<br />
these zones togcther with an additional 18 (7Vo) on some<br />
part of the seat structure. Slightly more sustained AIS 2<br />
head injuries from lhese sources, S2 (7Vo) with another<br />
2O (SVo) from striking the seat. These contacts were less<br />
often associated with the more $evere injuries.<br />
Thc low number of injuries arising from a contact<br />
with parts of the car subject to ECE Regulation 21 could<br />
bc a measure of its effectiveness. The energy absorption<br />
capabilities could be prcventing any head contact from<br />
resulting in large numbers of injurics cvcn at AIS l.<br />
Howcver it is not easy for ficld investigations to allocate<br />
a contact with a part of thc body when there is no injury<br />
and the CCIS data does routincly record this. Equnlly the<br />
effcct of restraint use might be to prevent a head contact<br />
with the facia or other structures subject to the hcadform<br />
test. Injurie$ would then be low even if the Regulation<br />
was completely ineffective. It is not possiblc to<br />
distinguish between each of these hypothescs and the<br />
effectiveness of thc Regulation can not be established.<br />
The low numbcrs of head injuries from parts of the car<br />
subject to the headform test do not indicate a need to<br />
change thc Regulation.<br />
Other contact areas pose I greater problem causing<br />
larger numbers of head injuries.<br />
The sclcction procedure for the sample of accidcnts<br />
investigated was such that accidents with more severely<br />
injured casualtics were preferentially selected for study.<br />
Casualties with head injuries wcre not preferentially<br />
$tudied over ca$ualties with other type.s of injury. The<br />
total numbers in each severity group of head injuries can<br />
not be compared although the percentages can. The 307<br />
restraincd front seat occupants in the sample shown in<br />
Table 8 represent 1549 in the population whereas thc 127<br />
fatalities represent only 202.<br />
By dcfinition minor head injuries do not pose a<br />
serious threat to life hut they are very common in the<br />
accident population. The most frcquent $ource of the AIS<br />
Sectlon 3: Technlcal Sessions<br />
I injuries of the restrained front seat occupants was the<br />
side-glass. l9Vo af the casualtics with AIS I head injuries<br />
alonc sustained them from the side-glass. All of the<br />
vehiclcs in the sample were fitted with toughened sideglass.<br />
Injuries from all glazed areas together represented<br />
33Vo of all AIS I head injuries of the restrained front<br />
seat occupants and 22Vo of thosc of the rear occupants.<br />
The very large number of casualties sustaining injuries<br />
from glass indicates a necd for improved glazing systems<br />
aimed at reducing minor injuries.<br />
The steering system was a licquent $ource of injuries<br />
to restrained front seat occupants. It accounted for l6Vo<br />
of their AIS I head in.iuries, 29Vo of their AIS 2 injuries<br />
and lTTo md l27o of the AIS 3+ injuries of thc survivors<br />
and fatalities respectively. Although it is possible that<br />
some steering wheels did comply with the headform tcst<br />
defined in ECE Regulation 12 there is no central source<br />
that records this. It has been observcd that some designs<br />
of steering whcel have large, well padded hub areas,<br />
prrddcd rims and recessed mounting nuts while others<br />
have cxposed metal spokes and protruding hub nuts.<br />
Although this study does not attempt to examine the<br />
effects of the various dcsigns it is reasonable to<br />
hypothesize that the injurics will vary. Thc high<br />
frequency of head injuries of all levels of severity<br />
indicates an urgent need to improve steering wheel<br />
design.<br />
Tables E and 9 indicated that the roof zone and the<br />
pillars frequently accounted for injuries of all levels of<br />
severity. ZlVo of the AIS 3+ injuries of the restrained<br />
front seat fatalities involved roof contact anrl l6Vo<br />
involved a pillar contact as did 267o of the head contircts<br />
of the unrestrflincd rear seitt faralitics. The manner in<br />
which ECE Rcgulation 2l defines the construction of the<br />
pillars and the roof is clearly inarlcquate to prevent many<br />
severe injuries. Tables l0 and I I show that injuries<br />
resultinB from contact with the sidc header rails are rare<br />
being between |o/a and 5To of all head injurics of<br />
restrained front seat occupants. The consequence of<br />
adopting proposals to reduce such injuries do not appear<br />
likely to be able to affect a major portion of those with<br />
head injuries.<br />
It is not evident however that the cxtension of the<br />
headform tcst to cover the roof and pillars will<br />
completely addrcss all head injuries from these sources.<br />
Table l3 has shown that intrusion is a frequent<br />
characteristic of thc interior contacts that result in the<br />
most severe injurics. Ilowever other studics have shown<br />
that intrusion is also a reflection of the severity of the<br />
impact to the vehicle and that the velocity of thc head<br />
contact is also an important factor. Inspection of the<br />
accident case records suggests that most intcrior contact<br />
area$ can exhibit intrusion. This suggests that there may<br />
be two types of crash condition between which the effect<br />
of intrusion may viily. One condition concerning struck<br />
side occupants, roll-overs and underruns for example,<br />
frequently show head contacts that occur at an early<br />
75<br />
;l<br />
..<br />
"s<br />
f!<br />
;-4
13th lntemetlonal Technlcal <strong>Conf</strong>erence on Experlmental Safety Vehicles<br />
stage of the crush. The normal position of the head is<br />
close to the shucture it eventually strikes and such a<br />
contact is often incvitable. It is this condition that<br />
Huelke and Strother have examined to show that the<br />
residual intrusion is a manifestation of the crash severity<br />
and is not a cause of head injury in itself.<br />
Another condition, concerning frontal impacts and<br />
non-struckside occupants for example, finds head contact<br />
areas that are not close to the normal head position.<br />
These areas might include the steering wheel or the far<br />
side door. In this condition a head contact might not be<br />
inevitable. When intrusion occurs it can move these parts<br />
of the car interior closer to the occupant and raise the<br />
likelihood of such a contflct occurring. If the impact<br />
severity and intrusion are sufficicntly sevcre the object<br />
will inevitably be moving at the moment of contact. The<br />
degree of intrusion in this condition is still a<br />
manifestation of crash severity as Strother and Huelke<br />
describe but the influence on injury is more complex.<br />
This analysis has found that the sevcrily of head<br />
injury increascs with the presence and amount of<br />
intrusion as well as with delta-V, this is in line with<br />
Strother and Huelke. The proportion of casualtics<br />
sustaining intruding contacts was approximately constant<br />
at injury levels above AIS I. It also shows that as head<br />
injurics become more severe the contacts that cause them<br />
bccome more commonly directly supported by the<br />
striking object. llVo of those sustaining AIS I head<br />
injuries alone contacted an intcrior structure that was<br />
supported as did 167a of the AIS 2 and AIS 3+ surviving<br />
restrained front seat occupants that were not ejected.<br />
However 4LVo of the AIS 3+ fatalities sustained such a<br />
contact and this variation was highly significant. It is<br />
useful to consider the possible effects of a contact with<br />
a supported structure. When a contact is supported its<br />
stiffness can change dramatically, the sheet of metal<br />
forming the roof can be very different when it is<br />
supported by a tree or a truck bumper. It seems likcly<br />
that this could influence the severity of head injury and<br />
is the cause of the increased incidence of supportcd<br />
contacts amongst the fatalities. The head injuries of the<br />
fatalities tended to be more severc than thosc of the<br />
survivors with AIS 3+ injuries. Although this is likely to<br />
be influenced by the severity of the impact to the vehicle<br />
the presence of a supporting striking objcct is also likely<br />
to bc a factor. This effect of supported contact areas is<br />
of also likely to apply to other injured body areas of the<br />
fatalities.<br />
Thc interaction of the head with intruding and<br />
supportcd structures has to be examined in more detail<br />
either experimentally or using computer simulations.<br />
Real-world crash invcstigations cannot determine the<br />
location or the velocity of an intruding structure at the<br />
moment a head contact occurs. An understanding of the<br />
link has to be achieved before the optimum countarmeasures<br />
or legislation can be introduccd.<br />
16<br />
Head contacts with objects outside the car were often<br />
associated with the most severe injuries. The restrained<br />
front seat occupants who survived with AIS 3+ head<br />
injuries made contact with an extcrior object in 317o of<br />
case$, a similar portion of the fatalities made contact<br />
with an objcct outsidc thc car. Amongst the unrestrained<br />
rear seat occupants the proportion was even higher with<br />
SlVo of the head contacts of the fatal group being outside<br />
the car. Table l2 shows that ejection was not common in<br />
any of these groups except for the fatally injured<br />
unrcstrained rear seat occupants. It is expected that<br />
restraint use will prevent some of the head injuries of<br />
this last group by preventing ejection and changes in<br />
injury patterns following the recent introduction of<br />
mandatory rear seat-belt use in the UK will be monitorcd<br />
with interest. Table 12 shows that most of thc injurics<br />
from exterior contacts are not a result of either partial or<br />
complete ejection so many of these objects must be<br />
intruding into the car. The head contact conditions are<br />
therefore similar to those with a supported inlruding<br />
structure. The only techniques available for mitigating<br />
thcse injuries involve avoiding contact when the<br />
intruding structure is remote or by controlling the<br />
occupant head kincmatics perhaps by improved restraint<br />
performance. Neither approach is easy but unlcss the<br />
problem is tackled the numbers of severe head injuries<br />
will not diminish. Again a more complete understanding<br />
of the relation between head injury and intrusion is<br />
required before these injuries can be fully addressed.<br />
Summary<br />
. 67Vo ol restrained front seat fatfllities sustain AIS 3+<br />
head injurics as do 78Vo of unrcstrained rear seat<br />
fatalities.<br />
. Survivors sustain injuries to other body areas more<br />
frequently than fatalities.<br />
. Fatalities whether restrained or uniestrained sustain<br />
AIS 3+ injuries to 2.6 body areas on average while<br />
MAIS 3+ survivors sustain between 1.15 and 1.25.<br />
. Glazing materials were very common sources of<br />
minor head injuries while the roof, pillars, steering<br />
wheel and front seats wcrc frcquent sources of AIS<br />
3+ injuries.<br />
' Contacts with objects outside the car were very<br />
frequently associatcd with the fatally injured<br />
casualties with AIS 3+ head injurics.<br />
. The contacts causing the most severe injuries were<br />
commonly intruding into the car and often supported<br />
by exterior objects.<br />
.47Vo of the unrestrained fatally injurcd rcar seat<br />
occupants were either partially or completely ejected<br />
from the car. 9lVo of thc rcstrained fronl. seat<br />
occupants who died wcrc not cjected at all.
Sectlon 3: Technlcal Sessions<br />
. The majority of head injuries were cau$ed by contact<br />
rfiuelke,<br />
DF; Marsh, JC; Sherman, HW. Analysis of<br />
with parts of the car not covered by current Rollovcr Accident Factors and Injury Causation. l6th<br />
regulations. These regulations do not take into <strong>Conf</strong>erence of thc American Association for Automotive<br />
account the effects of intrusion or support from the<br />
striking objects.<br />
. The paper calls for improvements in the crash<br />
performance of glass, steering wheels, pillars and<br />
roof structures.<br />
. There is a need to improve the understanding of the<br />
interaction between the head and intruding supported<br />
structures and with objects outside the car.<br />
Medicine 1972.<br />
raHuelke,<br />
DF; Marsh, IC; Dimento, L: Sherman, HW;<br />
Ballard, WJ. Injury Causation in Rollover Accidcnts.<br />
lTth <strong>Conf</strong>erence of the American Association for<br />
Automotive Medicine 1973.<br />
t5Huelke,<br />
DF; Lawson, TE; Marsh, JC. Injuries,<br />
Restraints and Vehicle Factors in Rollover Car Crashes.<br />
Accident Analysis and Prevention Vol 9 pp 93- 107 1977.<br />
r6Huelke,<br />
DF; Compton, CP. Injury Frequency and<br />
Scverity in Rollover Car Crashes as Relatcd to Occupant<br />
Ejection, Contacts and Roof Damage. Accident Analysis<br />
References<br />
tMucciardi, and Prevention Vol l5 pp 395-401 1983.<br />
A. Prediction of brain injury measures from ttstrother,<br />
CE; Smith, GC; James,MB; Warner, CY.<br />
head motion parameters. 2lst Stapp car crash conference<br />
Injury and <strong>Int</strong>rusion in Sidc Impacts and Roll-ovcrs. SAE<br />
1977.<br />
840403 1984.<br />
Nusholt, GS. Head impact response-skull dcformation lsBahling,<br />
GS; Bundorf, RT; Kaspzyk, GS; Moffatt, EA;<br />
and angular acceleration. 28th Stapp car crash conference<br />
Orlowski, KF; Stocke, JE. Rollovcr and Drop Tests - The<br />
1984.<br />
3Stalnaker,<br />
Influcnce of Roof Slrcngth on Injury Mechanics Using<br />
RL; Low, TC. Translational energy criteria<br />
Belted Dummies. 34th Stapp Car Crash <strong>Conf</strong>erence,<br />
and its correlation with injury in the sub-human primate.<br />
1990.<br />
IRCOBI I987.<br />
rePenoyre,<br />
4Ward, S. An impact test programme using 6 models<br />
C. Finite element modcls of the head and their<br />
of lower-mcdium sized car. 10th Expcrimental Safety<br />
use in brain injury research. 26th Stapp car crash<br />
Vehicle <strong>Conf</strong>erence 1985.<br />
conference 1982.<br />
zoMonk,<br />
MW; Gabler, HCI Sullivan, LK. Subsystem<br />
lTong, P; Eppinger, R. Finite element modelling of head<br />
testing for head to upper interior safety. I I Experimental<br />
injury caused by inertial loading. 12th Experimental<br />
Vehicle <strong>Conf</strong>crence 1987.<br />
Safcty Vehicle <strong>Conf</strong>erencc 1989.<br />
z'Otubushin.<br />
EBoock, A: Galer. MD. Crashed Vehicle Examina-<br />
RJ; Thibault, LE. An Experimental and<br />
tion Techniques. SAE Congress, 1986.<br />
analytical approach to the developmcnt of a range of 22Mackay,<br />
GM; Galer, MD; Ashton, SJ; Thomas, P. The<br />
neurovascular trauma indices. IRCOBI 1990.<br />
TThibault, Methodology of in-depth studies o[ car crashes in<br />
LE; Genarelli,TA; Margulies,SS;Marcus,J;<br />
Britain. SAE papcr 850556 1985.<br />
Eppinger,R. The strain dependant pathophysiological<br />
consequences of incrtial loading on central nervous Acknowledgements<br />
tissue. IRCOBI 1990.<br />
sMeaney, DF; Thibault, LE. Physical model studies of<br />
The authors would likc to thank all the members of<br />
the Accident Research Units at Loughborough and<br />
cortical brain deformation in response to high strain rate Birmingham Universities and thc Dcpartment of Trans-<br />
inertial loading. IRCOBI 1990.<br />
eviano, DC- Perspectives on head injury research.<br />
rRcoBI 1985.<br />
'\Iy'alfisch,<br />
G; Pouget, Di Thomas, C: Tarriere, C. Hcad<br />
port Traffic Area Teams who collcctcd the data on which<br />
this paper is based. The financial support of the UK<br />
Dcpartment of Transport, the Transport and Road<br />
Research Laboratory, the Vehicle Inspcctorate Executive<br />
risks in frontal impacts: Similaritie.s and differences Agency, Ford Motor Company Ltd, Rover Group and<br />
between tests and real-life situations. lZth Expcrinrental<br />
Safety Vehicle <strong>Conf</strong>erence 1989.<br />
"Bradford,<br />
MA; Otubushin, A; Thomas, P; Robertson,<br />
NKB; Green, PD. Head and fasc injuries to car occu-<br />
Nissan Motor Company has bccn essential.<br />
The help from all the hospitals, HM Coroners and<br />
Police Forces in the UK that have helped the study by<br />
providing data has also been invaluable. Keith Clemo at<br />
pants in accidenrs-field data I983-85. IRCOBI 1986.<br />
r2Thomas, P. Head and torso injuries to restrflined drivers<br />
the Motor lndustry Rcscarch Association and John Cow<br />
at the Department of Transport gave the authors cssential<br />
from the steering system. IRCOBI 1987.<br />
assistance with interpretations of the regulations.
13th lnternatlonal Technlcal <strong>Conf</strong>erence on Experlmental Satety Vehicles<br />
sr.0-09<br />
Car Model Safety Rating-Further Development<br />
Using the Paired Comparison Method<br />
v Koch M, Kullgren A, Lie A, Tingvall C<br />
Folksam Research and Chalmers<br />
University of Technology<br />
Abstract<br />
During the last years, the interest in rating the interior<br />
safety of different cars and constructions have increased.<br />
Several methods have been used, based on either<br />
laboratory crash tests or on rcal lifc accidcnt data.<br />
Several limitations are related to both methods, and there<br />
is no universally accepted method to rate cars in rclation<br />
to each other.<br />
One technique that has been proved to be powerful in<br />
car safety rating is the paired comparison method<br />
proposcd by Evans. In this method, the most important<br />
exposure parameter, accident severity, can be controlled.<br />
The method has, however, some fundamental drawback<br />
and that is the fact that only a part of the accident<br />
population can be used. Single accidents, and accidents<br />
with trucks, buses etc must be omitted.<br />
In this prcscntation a techniquc to cxpand the accident<br />
data is showcd. It is also shown how aggrcssivencss can<br />
affect the results in safety rating, togcthcr with some<br />
other results of using paired comparisons.<br />
Background<br />
One of the most difficult problems in the field of<br />
rating cars and car design by using real life accidents, is<br />
to handle the exposure problem. This problem is though<br />
both a problem of how many vehicles or occupants that<br />
are involved in accidents. but also the sevelity of these<br />
accidents.<br />
The severity of accidents is known to be a strongly<br />
predicting parameter lbr injuries. In large scale data<br />
bases it is, however, most complicated to have<br />
measurcments that can be used for accident scverity<br />
estimates hy accident reconstruction. An indirect method<br />
where the accident severity can be taken care of within<br />
the accident material can therefore be hclpful. Such a<br />
method has been developed for car accidents by Evans<br />
(3) and further developed by Tingvall and others. ln this<br />
method, called paired comparison (single and double<br />
paired) the whole exposure complex can be handled.<br />
In this study, the method has been developed further,<br />
and some specific questions are studied by using the<br />
mcthod. Such questions are the influence of vehicle mass<br />
vs vehicle design. As it is believed that there is a<br />
relationship between these two variables, the are often<br />
mixed togethcr, and it is believed that the influence of<br />
weight is overestimated (l).<br />
The objectives of the study were to:<br />
?8<br />
. Find ways to increase thc study material in paired<br />
comparison technique,<br />
. Analyzc the influcnce of true mass effects in relation<br />
to design,<br />
. Study the influence of aggressiveness.<br />
Method<br />
The fundamental problem can be described with<br />
probability distribution functions. In Fig. 1 two<br />
hypothetical curves showing the risk of injury linked to<br />
accident severity for two different car models is showed.<br />
One car is better than the other in that thc distribution is<br />
shifted to the right, that is for a given accidcnt severity,<br />
the probability of injury is lower.<br />
P(t)<br />
Figure 1. Scematic Probability Functions for Injury Risk<br />
for Different Accident Severity.1($) refers to car 1 and<br />
tr(s) to car 2.<br />
In Fig 2. Two accident severity distributions for two<br />
car models is showed. The distributions are hypothetical.<br />
Car (2) is involved relatively more frequently in sevcre<br />
collisions comparcd to car (l).<br />
number<br />
of<br />
accidents<br />
accident severity (s)<br />
accident severity (s)<br />
Figure 2. Schematic Distribution of Acident Severity.<br />
f,(s) refers to car I and fr(s) to car 2.
The accident severity disribution is, however,<br />
unknown for different car models. This would not create<br />
any problem if all accident severity disFiburions for<br />
different cars were identical. This seem.s however to be<br />
a too optimistic assumption. There is though one<br />
situation where this is true and that is when the two<br />
different car models collide with each other (given a<br />
mass relation of 1:l).<br />
According to Evans, the relation of injuries for car I<br />
and 2 given the same accident severity distribution is;<br />
d/e where:<br />
d = the number of injured in car I = N/t,(sX(s)ds<br />
e = the number of injured in car 2 = N/ tz(s)f(s)ds<br />
N = total number of accidents<br />
For a given segment m where the accident severity can<br />
be considered to be constant (Fig. 3) d and e can be<br />
considered to be products of two probabilities; P, and P2,<br />
where P, is the risk to injured in car I for a given<br />
severity and P2 the corresponding probability for car 2.<br />
ccident severity (s)<br />
Flgure 3. Segmentod Probability Functions lor Injury Risk<br />
for Different Accident Severity for Car 1 \(s) and Car 2<br />
t'(8)<br />
Table la. Probabllltler of Inlury in Car I and 2 In a Given<br />
Segment of Accident Severity<br />
(rl<br />
injurcd<br />
not injurod<br />
iniured rn<br />
Crr Z<br />
rorrl Np,p? . N(l - p,)A - Np"<br />
not injured in<br />
t4tJ<br />
Np,p"+Np,(l-p1)-Hp1<br />
In table la the probabilities iue separated. The probabilities<br />
are assumed to be independent for all given<br />
segmcnts where the accidcnt severity and probabilities of<br />
injury respectively can be considered as constant. It can<br />
be seen that the ratio d/e in this segment is equal to the<br />
ratio<br />
R = xr+xalx,+x, (where d=xr*xr and e = x,+xj<br />
which is the same as<br />
Sectlon 3: Technlca/ Sessions<br />
R=p,tp,tffi]<br />
X, is not used due to the fact that accidents with<br />
uninjured are not known in most data materials.<br />
It is easy to show that if prlpz is the estimator for a<br />
given segment, it is also truc for the whole range of<br />
accidcnt severity. Idcntical formulas are therefore used<br />
for all accidents together.<br />
Thc complete accidcnt matcrial used is shown in table<br />
lb.<br />
Tabfe 1b. Probabifity of InJury and Number of Injured for<br />
All Segmenls of Severity of Accidents: Drivers and<br />
Fassengers<br />
Crl<br />
injured<br />
not iniured<br />
m<br />
t<br />
E<br />
i'l<br />
injured<br />
(N, p', po) - X,<br />
(N, (r - p,) p,) - )q<br />
Nq<br />
Cer I<br />
not injured<br />
E (N, p,, (l - pr,)) 'X,<br />
i-t<br />
It is also possible to include passengers under some<br />
simple assumptions. By assuming that all cars have a<br />
similar proportion of front sent passenger, all accidents<br />
where there are injured passengers can be used, although<br />
it is not known lrom the accident material if there was<br />
an uninjured passenBer in the vehicle, too.<br />
The individual N, is the numbcr of accidents in a<br />
given segmcnt, It is easily understood, that a higher<br />
proportion of severe accidents will lead to a relativcly<br />
largcr X, vs X- and Xr.<br />
Thc same assumptions and theory ate used for estimat'<br />
ing the variance of the estimates p1lp2. By using<br />
Cochran's theorem for subdivision of variances, it can be<br />
seen that the variance could be calculated from the<br />
sstimates of p, and pr. By using Gauss approximation for<br />
the variance of ratios, the variance is calculated by:<br />
, p.* | (l-p,+) l-p.*<br />
f(R)=I-' l--'=*,-''t,I<br />
Pr* (x, +xr) (r, +xr)<br />
[ J<br />
p,+/pz+ is estimated by R, while p,* and pr+ must be<br />
chosen arbitrarily.<br />
It can be understood from the formulas that the<br />
method as described above cannot be used directly on a<br />
true accident material, as the number of combined<br />
accidents for different cars will be to few. Instead, the<br />
opposite car (ic car 2) will bc all cars that were involved<br />
in accidents (with car 1). Thcreby, it must be assumed<br />
that the distribution of all opposilc cars is similar tor all<br />
investigated car models, or can bc normalized. If so, the<br />
Nn<br />
79
lSth lnternatlonal Technlcal <strong>Conf</strong>erence on Experlmental Satety Vehtctes<br />
opposite cars must be known concerning make, model<br />
and weight. It is also obvious that there must be a<br />
possibility to compensate for other mass relation than l: I<br />
as the opposite car can gain from a low weight car and<br />
vice versa.<br />
In table 2, an example of one car is shown. The<br />
weight of this car is approx. 1200 kg, but no attention<br />
has been paid to the mass ratio to the opposite cars. The<br />
correct interpretation of R is that in 84Vo of the accidents,<br />
where at least one driver was injured, there was an<br />
injury in the SAAB 900.<br />
Table 2. The Number of Drivers Inlured in SAAB 900,<br />
and Cars Collidlng with SAAB 900. xl relers to drivers<br />
inlured in both carf . xu is the number ol cars where<br />
the driver inlured in SAAB 900 but not in the opposite<br />
case while x. refers to the opposite case.<br />
\= 122<br />
xa = 166<br />
Xt= 22Q<br />
{=33i<br />
Results<br />
The influence of weight and design<br />
In general, the influence of design can be defined in<br />
a way where it is possible to extrirct this influence in a<br />
double pair equation. In crashes with cars of identical<br />
wcight (no mass influence), the probability of injury can<br />
be separated in the following way in a casc where just<br />
one car model or class of vehicles is studied. The desien<br />
parameter is noted as c.<br />
Schems lor Subdividing Cars with ldentical Mass<br />
CAR 1<br />
:<br />
injured<br />
injured c'p'<br />
CAR 2<br />
not injured cp(1-cp)<br />
not iniured<br />
cp(1 -cp)<br />
The rclation between the number of cases where just<br />
one is injured compared to ca$es with injuries in both<br />
vehicles is a measure of p. A large p leads to many cases<br />
of injured in both cars, assuming that the accident<br />
severity distribution is identical. The design factor can<br />
be isolated if sets of accidents with identical vehicles in<br />
terms of ,?ldJJ or other characteristics is divided<br />
to the given scheme. If cars of I00 kg<br />
difference are compared we can isolate tho design factor.<br />
In table 3 this 100 kg design factor is shown. To isolate<br />
the design effect the following calculation is made.<br />
Ro = (X,/X)Bo/(Xr/Xz)eoo<br />
Tabfe 3. Hefatlon of Infurles Accordlng to Scheme,<br />
lor Gars of Diflerent Weight<br />
weight relation (Ro)<br />
1000- 900 kg<br />
1 100-1000 kg<br />
1200-1 100 kg<br />
1 300- 1 200 kg<br />
1400-1300 kg<br />
0.gl<br />
1.12<br />
0.76<br />
0.87<br />
1.08<br />
The average design effect is 5.LVo in this comparison.<br />
It could however to $ome extent be influenced by a<br />
higher accident severity for the heavier cars. This is,<br />
however, in contrast to the lack of consistency in the<br />
design factor.<br />
The weight effect is calculated from the rclation when<br />
cars of different weight are colliding. In table 4 the<br />
relation for cars colliding with other cars of 100 kg<br />
highcr service weight are compared.<br />
Table 4. Relative lnjury Risk Levelfor Cars of Different<br />
Weight<br />
weight<br />
relation (Ro-*)<br />
1000- 900 kg<br />
1 100-1000 kg<br />
1200-1 100 kg<br />
1300-1200 kg<br />
1400-1300 kg<br />
0.85<br />
0.87<br />
0.91<br />
0.89<br />
0.86<br />
The average design and weight effect was 117o. This<br />
mcans that the true weight effect was only 7Vo for every<br />
100 kg while the rest was the design effect. The weight<br />
eff'ect is though doubled as it gives a positive effect ro<br />
one of thc cars and a ncgativc to thc other, so the true<br />
weight effect is only half of the calculated 77o, that is<br />
3.SVo in the limited range given in the table.<br />
Thc compensation lor mass effects in the paired<br />
comparison modcls should bc lowered that what seems<br />
to be correct from the beginning.<br />
The Use of Passengers in the Faired Comparison Method<br />
In the original method only the drivers were includcd.<br />
The passengers can though be treated in the same way.<br />
This though is based on iln assumption that there arc<br />
identical numbcrs of passengcrs in all cars compared.<br />
This may be a too optimistic assumption, and thcrcfore<br />
a comparison of thc drivcr and passcngcr risk was compared.<br />
In fig 4 this is done antl by using a polynomial<br />
modcl, and a good relationship was established.<br />
The results of the paired comparison method used on<br />
car rating will change whcn mass and passenger effects<br />
are taken into account. The diffcrencc is shown in table<br />
).<br />
In table 5 it can be seen that the wcight and the passenBer<br />
factor changes the outcome to different amount<br />
for different car models. In general, the difference<br />
between the small and thc largc car is becoming smaller.
1,3<br />
1,2<br />
1,1<br />
1<br />
0,9<br />
0,8<br />
750 1 000 1 250 1 500 1 750<br />
weight<br />
Flgure 4. Belation Between Drlvor/Passengers and Welght<br />
of the Vehicle in a Paired Comparison. The polynom hae<br />
the equation Y = 2.54 - 2.01 '10'3 X + 6.5 ' 10-7 )c.<br />
Table 5. Eramples of Corrections ol Palred<br />
Comparleone When Corrscting for Passengers end<br />
Welght Factor<br />
Car model weight unconected corrsct€d<br />
score $care<br />
Opel Corsa 800<br />
Nissan Micra 800<br />
Ford Sierra 1200<br />
Audi 80 1200<br />
MB W e01 1300<br />
Volvo 700 1400<br />
1.62<br />
2.13<br />
1.04<br />
1.02<br />
0.95<br />
0.69<br />
1.44<br />
1.89<br />
1.08<br />
1.0s<br />
1.02<br />
0.76<br />
Aggressiveness<br />
If a car is more aggressive in collisions with other<br />
vehicles, it could have certain effects on the accident<br />
figurcs in a paired comparison. The term aggressivcncss<br />
is not rlcfincd, but in this study, the structural aggressiveness<br />
was separated from aggressiveness due to maris.<br />
In order to have an idea about the structural aggressiveness<br />
a list of cars were presented to a car manufacturer<br />
with the aim to categorize thc cars into (hree groups;<br />
"soft,<br />
mcdium and stiff' cars. I cars were possible to<br />
dividc into the three groups. In table 6 the results of the<br />
in a paired comparison is presentcd. It can be seen that<br />
while the cars chosen had t similar overall result (R), the<br />
relativc ratio when the car collidcd with itself wfls very<br />
high for the stiff cars, especially for car A, while whcn<br />
colliding with all other c.lrs it was normal for the size of<br />
the car. The soft cars, howcver, had a completely different<br />
profile, where the relative ratio was very low.<br />
Sectlon 3: Technlcal Sessions<br />
Table 6. The Relatlve Rstioa In Palred Comparlsont<br />
for Different Car Types Where A ls a Stifl Car, B Are<br />
Soft Cars, While C Was Considered to be a Normal,<br />
But Stiff Car<br />
A . 0.67<br />
B 0.71<br />
c 0.66<br />
R XID(Z+X3<br />
to itself<br />
0.59<br />
0,25<br />
0.45<br />
XID(2+X3<br />
to other<br />
0.35<br />
0.37<br />
0.37<br />
An explanation that the stiff car was involved in more<br />
high speed accidents does not scem to be plausible, as<br />
the ratio of cases with two drivers injured vs onc of them<br />
was not higher when the "stiff' car collidcd with illl<br />
typcs of cars (0.35). Whcn the -'stiff' car collided with<br />
the "soft" cars, the relative paired ratio R* was 0.84<br />
which was lower than expected (0.94). When the<br />
"mcdium-stiff"<br />
car (C) collided with A and B rcspectively,<br />
the result was better for C (0.88 and 0.86<br />
respcctivcly).<br />
In summary, the "stiffl' car seems to have a higher<br />
injury risk when colliding with another stiff car, but also<br />
have a slightly better position whcn colliding with a<br />
*'soft"<br />
car, while when<br />
"soft"<br />
cars collide with each<br />
other. the total outcome is far better than othcr<br />
combinations.<br />
Discussion<br />
The possibility to comparo diffcrent aspects in car<br />
populations conccrning interior safety is of particulitr<br />
interest not only to the consumer, but also to research<br />
and car construction. ln such comparisons, however, the<br />
safcty performance of differcnt cars is difficult to isolate,<br />
as it may be conlounded by driver bchavior and lype of<br />
vehicle use leading to different accident experience. The<br />
possibility to collect data whcrc i e accident sevcrity is<br />
assessed is difficult on a large scalc data basis, both as<br />
it is costly and time consuming, but also because it<br />
normally will lead to insufficient data quality (5).<br />
Thc dcvelopment and usc of the paired comparison<br />
method has been succe$sful in taking care of the two<br />
most sclious prclhlcnts in analyzing large scale data<br />
materials: exposuro in ternrs of how many accidents that<br />
occur, and accidcnt severity. It is howcver an indirect<br />
and rclative method that will leave measurements on<br />
absolute rclations between exposure and injuries hidden.<br />
It is also a method that, at least at this ntotnent, does nol<br />
take all accidents into account. Single accidents and<br />
accidents with trucks etc will not bc covered bv thc<br />
method.<br />
In this study, the influence of somc critical parameters<br />
was analyzed using thc paired comprrison mcthod. Firstly,<br />
the influence of nrass vs design was studied. Several<br />
studies during a long period of ycars have shown, that<br />
there is a strong and consistent relationship bctwecn car<br />
weight and risk ot injury (4). This is a causal relation as<br />
j:<br />
I<br />
1i<br />
lt<br />
A<br />
E
13th lnternatlonal Technlcal <strong>Conf</strong>erence on Experlmentat Satety Vehlcles<br />
it is easily shown that a car of a lower weight will<br />
experience a higher change of velocity than heavicr cars<br />
and as change of velocity is correlated to injuries, it is<br />
not surprising that smaller cars will generate more<br />
injuries compared to bigger cars, given that they will be<br />
involved in accidents with each other. It seems, however.<br />
that in most studies, thc weight has been the only factor<br />
taken into account when comparing different car designs.<br />
It has though been pointed out (l) that thcrc might be an<br />
overestimation of the influence of vehicle weight. A<br />
larger and more heavy car will mo$t often also have<br />
larger interior dimensions, more distance to dcform and<br />
a better safety design that also will influence the<br />
outcome in accidents. If weight and these factors are<br />
highly correlated, it is easily understood that the<br />
"wcight"<br />
factor also will include<br />
"design."<br />
In thc prcsent<br />
study, a simple method to sepflrate weight from design,<br />
was tried. With some assumptions about accident<br />
severity, it was shown that the influence of dcsign in<br />
general was more important than weight. In average, the<br />
100 kg more service weight was associated with 3.570<br />
lower injury risk, while the design factor for the same<br />
amount of weight increase wus 5.2Vo.<br />
The above mentioned rcsults are of great importance<br />
when discussing downsizing as well as small car safety<br />
in the future. A smallcr car seems to have a possibility<br />
to be more safe by design, given that it can be<br />
constructcd in a good way. In the present material, it was<br />
shown that among small cars (800 kg) there are cars with<br />
the safety of much larger cars and, if thcrc arc only cars<br />
of the same sizc, thc totill safety does not have to bc<br />
much influenccd. The relation between design and<br />
weight makes it more important to evaluate the influence<br />
of differcnt safcty measures and to use scientific<br />
mcthods to evaluate the safety of different cars and<br />
constructions.<br />
In order to expand the data material available for<br />
compared comparisons, the integration of passengers into<br />
the method was studied. In this prcsentation, all<br />
passengers of l8 years were includcd, and a method to<br />
take the size of the car and the proportion of passengers<br />
into account was shown. The possibility to include also<br />
the pflssenger even if two-car accidents are studied<br />
makes it possible to evaluate safety designs also for the<br />
passenger, such as seat belt pretensioners, airbags etc.<br />
Aggressiveness, defined as the harm produced by one<br />
car to another, might influencc the paired comparison<br />
82<br />
method. A method where some car models were divided<br />
into "stiff' and "soft" cars were applied to thc data. If<br />
was found, that while there where only small differences<br />
in the overall results for these cars. the outcome was<br />
quite different when they collided with cach other. In<br />
such cases, the "stiff" cars had a high proportion of<br />
cases where there were injuries in both cars, whilc in the<br />
"soft"<br />
cars this occurred more seldomly than normal.<br />
This fact could not be explained by a higher accident<br />
severity among the "stiffl'cars. It was also found, that<br />
the relative injury risk was higher than expected whcn a<br />
"stiff'<br />
car collided with<br />
"soft"<br />
a car, though this<br />
diffcrence was fairly small.<br />
The results presented points out an important issue for<br />
the future. Dynamic test methods used in legislation and<br />
consumer guidance might influence the structural<br />
behaviour desired in car construction in a way that it<br />
might lcad to cflrs not optimized for a real life accident<br />
population. It is thereforc of great importance that this<br />
field is given more priorities by i e collecting more<br />
adequate data from thc rcal life, and by studying thc<br />
relative importance of different factors associatcd with<br />
the structure of cars.<br />
References<br />
l. Gloyns PF, Rattenbury SJ, Kullgren A, Lie A,<br />
Tingvall C, Etlwards J, Hill R. The correlation<br />
between the Consumer's Association secondary<br />
safety rating systcm and the Folksarn car safcty<br />
ratings. In: Proc IRCOBI <strong>Conf</strong> l99l:49-60.<br />
2. Krafft M, Kullgren A, Lie A, Nygrcn A, Tingvall<br />
C. Car model safety rating bascd on real life<br />
accidents. ln:Proc IRCOBI <strong>Conf</strong> l99l:25-39.<br />
3. Evans L. Double pair comparison-a new method<br />
to determine how occupant characteristics affect<br />
fatality risk in traffic crashes. Acc. Anal and Prev.<br />
Vol l8 no 3 pp 217-221.1986.<br />
4. Nygrcn A. tnjuries to car occupants-some aspects<br />
of thc interior safety of cars. A study of a five-year<br />
material from an insurancc company. Thesis. Acta<br />
Otolaryngologica suppl 395 Stockholm 1984.<br />
5. Kamrcn B, v Koch M, Kullgren A, Lic A, Nygren<br />
A, Tingvall C. Advanced accident data collectiondescription<br />
ancl potentials of a comprehcnsive data<br />
collection system. Accepted for publ <strong>ESV</strong> <strong>Conf</strong><br />
199 l.
st.o.t0<br />
Driver Fatality Risk in Two-Car Crashes:<br />
Dependence on Masses of Driven and Striking Car<br />
Leonard Evans and Michael C. Frick<br />
General Motors Research Laboratories<br />
Abstract<br />
Relative risk of driver death in a two-car crash is<br />
estimated as a function of the mass of each car using<br />
driver and (to measure exposure) pedestrian fatalities<br />
coded in the Fatal Accident Reporting System (FARS).<br />
Because mass effects flre less strong for more recent<br />
cars, the study uscs modcl-year 1980 and later cars. A<br />
three parameter analytical function fitted to the estimated<br />
risks generated the following fintlings. When a driver<br />
transfers to a lighter car that driver's fatality risk<br />
increases. while the other involvcd drivcr's risk declines.<br />
When cars of the same mass crash into elch other.<br />
fatality risk is lower when both cars are heavier. If one<br />
of the equal-mass cars is replaced by another lighter by<br />
any amount, lhe increase in fatality risk to the driver in<br />
the car of reduced mass exceeds the reduction in fatality<br />
risk for the driver in the unchanged car (that is, net risk<br />
increases). Net driver fatality risk (or net fatalities) in a<br />
car population increases if any car in thc population is<br />
rcplaced by a lighter onc, or if one population of identical<br />
cars is replaced by another population of lighter<br />
identical cars. Making all cars in a population of uniform<br />
mass while keeping the average mass constant increases<br />
net fatality risk. The safety disadvantage of lighter and<br />
smaller cars is intrinsic*it cannot be negated by design<br />
changes if these are also available to larger heavier cars<br />
because, when all other factors are cqual, more mass and<br />
more space can be used to provide increased safety. Fuel<br />
economy and safety (like higher speed limits and safcty)<br />
are intrinsically in conflict; individual and national<br />
choices require a balancing of advantages.<br />
<strong>Int</strong>roduction<br />
One of the most firmly establishcd cffccts in Faffic<br />
safety is thflt a car occupant's risk of injury or dcath in<br />
a crash is inversely related to the size or mass of the car<br />
in which the occupant is travelling. A large number of<br />
studies, conducted over more than two decades, have<br />
explored many aspects of relationships betwcen car size<br />
and safety [Evans l99l]. For the case of two-car crashes,<br />
mass is a particularly appropriate variable because of its<br />
central role in equations dcscribing thc dynamics of<br />
collisions. One recent study [Evans and Frick l99la]<br />
reports precise relationships between the ratio of driver<br />
fatality risk in thc lighter compared to the heavier car<br />
ilnd the ratio o[ thc hcavicr to the lightcr car mass. These<br />
relationships show that when late model year 900 kg and<br />
1800 kg cars crash into each other, driver fatality risk in<br />
the 900kg car is six times what it is in the 1800 kg car,<br />
or when 1000 kg cars and 1500 kg cars crash into each<br />
Sectlon 3: Technlcal Sessions<br />
other, driver fatality risk in the 1000 kg car is three<br />
times what it is in the 1500 kg car. Because that study<br />
focussed exclusively on risk ratios, it could be conductcd<br />
without any exposure measure. However, the relationships<br />
derived do not allow us to compare, say, the risk<br />
faced by a driver in a 900 kg car crashing into a 1800 kg<br />
car to the risk faced by a driver of a 1000 kg car kg<br />
crashing into a 1500 kg car. Comparisons of this type<br />
require an estimate of exposure to crash involvement.<br />
Method<br />
Data<br />
The Fatal Accident Reporting System (FARS) is a<br />
computerized data file maintained by the National<br />
Highway Traffic Safety Administration containing<br />
detailed information on all traffic crashes occurring in<br />
the United States since I January 1975 in which anyone<br />
was killed [National Highway Traffic Safety Administration<br />
l99ll. The exposure data, as well as driver fatality<br />
data, are extracted from crashes coded in FARS involving<br />
cars of known mass. The main results arc derived<br />
using data from 1980 through 1989, and include only<br />
cars of model year (MY) l9E0 or later. Wc focus mainly<br />
on MY > 1980 data because earlier analyses [Evans and<br />
Frick 1991a] showed substantial changes in mass<br />
dependencies between later and older MY cars. For<br />
comparison and modeling purposes, the analyses are also<br />
applied to cars of all model years. The average model<br />
year of cars in the analysis with unrestricted modcl years<br />
was 1976.2, compared to 1983.4 for the MY > 1980<br />
case; when no ambiguity arises, we shall sometimes refer<br />
to thc$c simply as'-older" and'-newer" cars. The average<br />
MY values are lower than the mid-point of the FARS<br />
years becausc 1980 MY cars (say) appear in 1989 FARS<br />
but 1989 MY cars cannot contribute to 1980 FARS.<br />
Driver fatalities<br />
The driver fatality data are for two-car crashes in<br />
which at least onc of thc drivers was killed. The data<br />
were segmented into catcgorics, or ranges, of mass each<br />
containing equal numbcrs of crashes (and consequently<br />
unequal intervals of mass). The number of categories<br />
chosen was the number which maximized the precision<br />
with which model parameters (discussed bclow) were<br />
determined.<br />
From a formal perspective, each of the cars involved<br />
in a two-car crash has a symmetrical role-they crash<br />
into each other. Howcvcr, for expository clarity it is<br />
convenient to arbitrarily distinguish between thern. We<br />
"first," "ith,"<br />
use the<br />
"struck," "subjcct,"<br />
terms<br />
"driven,"<br />
or "your" car to identify a car in the ith mass catcgory;<br />
the average mass of cars in the ith mass category will be<br />
represented by mi. The terms "second," "jth," or<br />
83<br />
jE
ISth lnternetlonal Technlcal <strong>Conf</strong>erence on Experlmental Satety Vehlcles<br />
"striking," identifies the "other" car, which is in a category<br />
with average mass mj.<br />
The pedestrian fatality exposure approach<br />
A number of applications of this method [Evans 1984]<br />
are described in Evans tl99ll. The aim is to estimate the<br />
exposure of cars to crashes in general using FARS data.<br />
The vast majority of crashes into such objects as trees,<br />
other vehicles, etc. are not coded in FARS, because only<br />
crashes in which someone is killed arc included in the<br />
file. However, if thc crash involves a pedestrian, and the<br />
pedestrian is killed, thcn the crash is coded. The<br />
assumptions that pedestrian fatalities are proportional to<br />
pedestrian crashes, and that cars strike pedestrians in the<br />
same proportion they strike other objccts in the driving<br />
environment, implies that the numbcr of pedestrian<br />
fatality crashes in which a group of cars is involved is<br />
proportional to the exposure of that group of cals to<br />
crashes in general. The assumption that pcdcslrian<br />
fatalities are proportional to pedestrian crashes holds if<br />
the probability ofa pedestrian fatality in a crash does not<br />
depend on the mass of the car. This is a reasonable<br />
assumption on physical grounds because the lightest car<br />
is so much heavier than the heaviest pedestrian that the<br />
car's crash trajectory is relatively unaffected by the<br />
collision.<br />
Results for MY > 1980 Cars<br />
Restricting the analysis to MY > 1980 excludes 877o<br />
of the otherwise availablc two-car crashes in FARS; the<br />
data reduction is so large because so many crashes<br />
between one MY > 1980 ciu and another MY < 1979 car<br />
are excluded. Sample size limitations make it infeasible<br />
to perform analyses for more recent sets of modcl ycars.<br />
In order to confine all aspects of the analyses to the<br />
1980s, data for FARS years 1980-1989 wcre used, thus<br />
excluding the vcry few crashes in 1979 involving two<br />
1980 model year cars.<br />
Table 1 shows driver fatality data for two-car crashes<br />
segmcntcd into I categories of car mass, with average<br />
valucs wl, w2, w3,.... w8. Using essentially the same<br />
approach and terminology as Evans and Wasielewski<br />
t19871 introduced to address a similar problem using<br />
earlicr data, we define<br />
N(i,j) = Number of drivers in cars in mass catcgory mi<br />
killed in crashes with cars in mass category m'', (l)<br />
where i and j assume values from I to L The risk of a<br />
driver fatality in a car in thc ith mass category comptrred<br />
to the risk in a car in the jth mass category when these<br />
cars crash into each other is given by N(i,j)A{(i,i). For<br />
example, 28 drivers in m, - w8 cars (avcrage mass 1683<br />
kg) were killed when these cars were in collision with m,<br />
= wl (870 kg) cars. In these same crashes bctwccn wl<br />
and w8 cars, 146 drivers in thc wl car$ were killed. We<br />
can immediately conclude that when wl and w8 cars<br />
84<br />
Table 1. The Number of Drlver Fatalltlee In Car | (wlth<br />
mass in the ith mass category) When This Car is in<br />
Collision with Gar | (mass in the lth category)<br />
Car<br />
i I<br />
w1<br />
u2<br />
rB<br />
w4<br />
r5<br />
rG<br />
ut7<br />
*8<br />
wtt t2<br />
r;;l<br />
t l<br />
76<br />
58<br />
E2<br />
41<br />
42<br />
40<br />
28<br />
Carj+<br />
103 106 118 118 153 160 146<br />
s9<br />
68<br />
63<br />
51<br />
3l<br />
32<br />
The averago masses of the I mass catogorios are;<br />
wl = 87O kg; w4 = 1147 kgj t7 = L472kg;<br />
Y2 = 98$ kg; uE = 1241 kg; wB = 1683ks.<br />
s3 = 1O79 kg; wE = 138O kg;<br />
90 101 LzS 129 133 132<br />
67<br />
78<br />
64<br />
61<br />
37<br />
101 93 116<br />
t92 |<br />
t l<br />
72<br />
62<br />
68<br />
37<br />
99 106<br />
t94 |<br />
t l<br />
76<br />
116<br />
123<br />
Data for MY > 1980 cars, FARS years 1980 through 1989,<br />
collide, drivcr fatality risk in the lighter car is 146/28 =<br />
5.2 timcs what it is in the heavier car.<br />
In order to progress to the gcncral case some measure<br />
of exposure is neccssary. Exposure is estimated using<br />
pedestrian ffltnlity crashes. The numbers of single-car<br />
crashcs in which at least one pedestrian was killcd is<br />
shown in Table 2, in which<br />
E(i) = num6*r of crashes by cars in mas$ category mi<br />
in which at lcast onc pedestrian was killed (2)<br />
The number of crashes between cars in the ith and jth<br />
categories is assumed proportional to lhc product of their<br />
cxposure, E(i)xE(i). The number oI drivcr deaths per unit<br />
of exposure, R'.r**..(ij) is therefore given by<br />
R'.**.,(i,j) = N(i,j)/tE(i)xE(i)1. (3)<br />
For convenience, the values of R'"n**".(ij) are rescaled<br />
so that the nominally lowest drivcr risk casc (thc risk in<br />
the heaviest car crashing into the lightcst) is assigned the<br />
value I. This is achieved by dividing cqn 3 by a<br />
constant, K, given by<br />
K = N(E,1)/[E(E)xE(1)]. (4)<br />
Thus we obtain the soueht-after measure of driver risk.<br />
R****(ij), given by<br />
68<br />
59<br />
a2<br />
t76 |<br />
t l<br />
61<br />
59<br />
95<br />
88<br />
t91 |<br />
t l<br />
58<br />
132<br />
134<br />
128<br />
113<br />
93<br />
E<br />
Ror,o*oo(i,j) = N(i,i)/tKxE(i)xE(i)1. (5)
Tablr 2. Thr l{umbrr ol gfngfa-Car Crarhor fn Which at<br />
Lesst One Pedestrlen Wer Killed Segmented into the<br />
Maar Crtegorlcr Uaed in the DrivBr Fetatity Analycio<br />
Category<br />
1<br />
2<br />
3<br />
I<br />
5<br />
6<br />
7<br />
I<br />
llaes, kg<br />
Minimum l,la x imum Averago<br />
655 ,0<br />
929.9<br />
ro42,4<br />
1113.<br />
1<br />
1184.3<br />
1300.6<br />
t126,2<br />
1558 . I<br />
929.O<br />
104r.S<br />
11 r2.7<br />
1183 .0<br />
1307 .7<br />
1421.7<br />
1556.3<br />
2131.9<br />
869.7<br />
984 .8<br />
1078.7<br />
1146.8<br />
7240.7<br />
1380 ,4<br />
L472.1<br />
1682 .7<br />
ilumber of Crashes<br />
1580 = E(1)<br />
148r = t(i)<br />
raoo c E(3)<br />
r41r = E(a)<br />
1379 = E(6)<br />
1397 = E(6)<br />
1707 ; E(7)<br />
1695 = E(8)<br />
Data lor MY > 1980 care, FAFI$ yBar8 tg8o rhrough 1g8g.<br />
Table 3 shows the computed values of R.r*-.'(ij).<br />
Apart from the values Rob*-"d(I,8) = 5.21, and the<br />
arbitrarily fixed R"r**o(8,1) = l, all other values are<br />
influenced by the exposure measure. The highlighted<br />
diagonal elements, representing cars of similar mass<br />
crashing into each other, show an increasing trend with<br />
Table 3. The Fetelity Riek to I Drivsr in Cer i When This<br />
Csr Crsshee into Cer J, Eaeh Car Being in the Category<br />
with the Indiceted Average Mase<br />
Car<br />
i<br />
I<br />
rl<br />
w2<br />
s3<br />
w4<br />
wS<br />
w6<br />
t7<br />
wB<br />
Carj+<br />
11* t2 wB w6 uB<br />
* Thu "rua"g6 riasses of the I mas* catogori€B ar6;<br />
ul = 870 kg;<br />
tt? = 985 kg;<br />
rB = 1079 kg;<br />
14 = 1147 kg;<br />
wS = 1241 ks;<br />
wG = 1380 kg;<br />
Y7 - 1472 kg;<br />
rB = 1683 kg.<br />
All valuer ere rcletiw to e velue one for the loweet riek cass, that<br />
faced by e driver of a car in the heaviest mass cat€gory crashing<br />
into a car in the lightest mass category. Date for My r t9B0 cars,<br />
FARS years 1980 through 1989.<br />
Sectlon 3: Technlcal $essione<br />
decreasing common mass, although the relationship is<br />
noisy.<br />
The estimated risk for wl cars crashing into wl cars<br />
departs particularly from the gcneral trend, the value<br />
being less than for w? cars crashing into wl cars (physically<br />
implausible) and much less than for the other<br />
adjacent cell, wl cars crashing into w2 cars. In contrast,<br />
the other diagonal values in Table 3 are similar to their<br />
adjaccnt non-diagonal elements. The departure from the<br />
trend is larger than plausible due to the sample size of<br />
fatally injured drivers (62, giving a standiud error of<br />
about l3olo).<br />
For a number of reasons it sccms unlikcly that when<br />
two very light cars crash into each other risk is really<br />
less than when two slightly less light cars crash into each<br />
other. First, it is implausible on physical grounds.<br />
Sccond, thrce indepcndcnt studics using state data to<br />
examine injury risk as a function of thc ma.s.s of each of<br />
two involved cars (Joksch Il983J, Evans and<br />
Wasielewski [1987], and Klein, Hertz. and Borener<br />
tlggll) find that when the masses are the s^ame, risk<br />
increases with decreasing mass without any evidence of<br />
anomalous behavior at the lowest masses. The unsystematic<br />
cflbct for wl cars crashing into wl cars is more<br />
likely reflecting departures from the assumptions of the<br />
pcdcstrian fatality exposurc approach. Thc wl cars may<br />
be morc likely to be used in cnvironments in which<br />
pedestrian-fatality crashes are more likely, lhercby<br />
indicating that their drivers were more exposed to<br />
filtillity risk than they were. If the wl cars had a<br />
dislribution oI crashcs by sevcrity morc skcwcd lowards<br />
Iower scvcrity crashcs, this would rcduce thc ratio of<br />
driver to pedestrian fatalities; support for such an<br />
intcrprctiltion is providcd by thc finding Lhat the<br />
probability that drivcr is killcd when a right-front<br />
passenger is killed is lower for wl cars than for other<br />
cars. Any error in the exposure for irny group of cars has<br />
a pflrticularly strong cffcct on thc highlighlcd diagonal<br />
values in Table 3 becausc the square of the exposurc<br />
mcasure appcars in thcir calculation. For cxamplc, if the<br />
actual exposure was 25Vo less than estirnated by E(l),<br />
thcn the top-left cell in Tablc 3 would bc 4.23 rather<br />
than 2.38.<br />
In order to hetter illuminate and explore the trends and<br />
dependencies in the data in Table 3, it is desirable to fit<br />
an analytical function to these data. An analytical<br />
function has important additional advantages. It can be<br />
used to examine the net safety effect when any car is<br />
replaced by another of a different mass. An analytical<br />
function can be used to compute how system safety<br />
responds to changes in the mix, by mass, of cars.<br />
Analytical<br />
fit<br />
The data in Table 3 were fitred to<br />
R'p**"*o(m',mr) = m," [l - exp (G x p* )l<br />
(6)<br />
85<br />
I<br />
ill<br />
Ii<br />
sfr<br />
'il<br />
1<br />
iq<br />
..{<br />
:i:<br />
i #<br />
.rl<br />
.:.1<br />
:i<br />
l
13th lntametlonel Technlcal <strong>Conf</strong>erence on Experlmental Safety Vehlcles<br />
where<br />
p = mr/m,<br />
(7)<br />
is the mass ratio, defined as in Evans and Frick tl99lal.<br />
This functional form was chosen not only because it<br />
provides a satisfactory fit to the data, but additionally<br />
because it exhibits physically reasonable behavior for the<br />
special cases of the masses being equal, and for the case<br />
of the mass of the struck car becoming arbitrarily large.<br />
In analogy with eqns 3 and 4, we define the constant<br />
kas<br />
k = R'r*o.*o(mr = w8' mz = wl)<br />
This enables us to define<br />
(8)<br />
Rr*ai"*a(m' me)=mrv[l -exp(G*p*)l /t (9)<br />
Thc inclusion of the constant k ensures that eqn 9<br />
gives the value one for m, = w8, m, = wl irrcspective of<br />
the values of the parameters. Thc criterion for best fit of<br />
eqn 9 to the data in Table 3 was the set of V, G and W<br />
parameters which minimized the quantity S = EZ?, where<br />
summation is over the 63 estimates, and Z - log<br />
(Rp,.ai",./Rou**.)' Estimating twice or half the obscrvcd<br />
value adds equally to S. At the minimum, the root mcan<br />
$quare value, /(5/63), is 0.1591. The interpretation is,<br />
very approximately, that the standard error of an estimate<br />
is about l6Vo of its value. The selection of I mass<br />
categories was based on minimizing the errors in the<br />
paramctcr estimates, and not rninimizing S, which is<br />
achicvcd by 7 categories; more mass categories tcnds to<br />
increase the precision of thc parameter estimatcs bccause<br />
it extends the mass range.<br />
The parameter values that provide the best fit are<br />
and<br />
v--0j22r0.139<br />
G=-Ll?5f0.181<br />
W = 2.427 t0.l2l<br />
(10)<br />
(ll)<br />
(12)<br />
where crror Iimits throughout this paper are one stflndard<br />
error. AII three parameters arc dimensionless, so that the<br />
cquation applies regardless of the mass units. Bccause of<br />
the way eqn 9 is normalized by the use of eqn 8, thc<br />
parameter V is really raising the dimensionless ratio,<br />
m,/w8, to the power V. This is why the value of V is<br />
unaffected by whether masses are mcasured in, say, kg<br />
or pounds.<br />
The standard errors given for the partmeters reflcct<br />
only differences bctween eqn 9 and the data in Tablc 3,<br />
and do not include any contributions from underlying uncertainty<br />
in thc overall method; in particular, thc use of<br />
pcdcstrian fatalities to estimirtc cxposure. Errors from<br />
86<br />
this source have the potential to influence results,<br />
especially strongly for the case of cars in the same mass<br />
category crashing into each other, as discussed previously.<br />
Predicted compared to observed values<br />
Table 4 shows the values of R*cdicrcd computed using<br />
eqn 9 with the parameter values shown in eqns 10-12.<br />
The predicted values may be compared to the observed<br />
values in Table 3. Figure I shows the predicted versus<br />
observed values, with Figure 2 displaying, on a log<br />
scale, the ratio of prcdicted to observed values. Of the 63<br />
predicted values, 54 arc within 20Vo of the observed<br />
values, which range over a factor of five. The largest<br />
error, 4.05/2.38 = 1.70, is that for the previously<br />
discussed case of wl cars crashing into wl cars.<br />
In what follows we assume that eqn 9 estimates the<br />
risk of fatality to a driver in a car of givcn mass when it<br />
crashes into another car of known mass, so that by<br />
examining the propcrties of this equation we can dcrive<br />
additional results rclating to two-car crashes.<br />
Table 4. Driver Fatality Risks Computed Uslng Eqn 7 with<br />
the Parameters lor MY > 1980 Care Given in Eqns 10-12<br />
Cer<br />
I<br />
t<br />
Car j +<br />
Y7 wB<br />
I T------t<br />
wt +.ez E.oG 5.28 5.50 5'71 5.78 5.85<br />
ll+.osl<br />
|_+r---_.1<br />
rz +.s9. l.er 4.ez E'21 5.3e 5-56<br />
13.27 le.sol<br />
-l-_l<br />
|<br />
ws 12.75 3.34 13.78 1 4.07 4.42 4.83 5'02 s.30<br />
' !-l<br />
*+<br />
|<br />
z.ez ,.n, il +.. o.tt 1.74 s.oe<br />
F.tt-l<br />
*s<br />
I<br />
e.os 2.86 z.n "* o.on I'gt 4-7a<br />
Is-e4<br />
*e z.o4 2.40 a.E7 s.01 s.ze o.to<br />
lr.or lt*l<br />
w7 1.77 2.1o 2.34 z.ez s'la g'se<br />
11.38 lt*l<br />
E<br />
t.so 1.s6 1.78 z.04 z.4s z.7r<br />
* Th" "ra""gt mattee of tho I ilaes catcgoriee art;<br />
w1 = 870 kg; 14 = 1147 kg; Y7 = 1472 kg;<br />
*2 = 985 kg; a$ = 1241 kg; w8 = 1683 kg.<br />
s$ = 1O79 kg; sE = 1380 kg;<br />
Derivations from the Analytical Fit to<br />
MY > 1980 Data<br />
'I'he<br />
effect rtf mass v,hen cars of similar mass crash into<br />
each other<br />
If two cars of the samc mass, say M, crash into each<br />
other, the relative drivcr fatality risk (equal in each car)<br />
is given by substitutitlg trl, = M and flj = M into eqn 9.<br />
Bccausc thc ma$s ratio is equal to onc, thc rclativc<br />
risk, R(M), for this casc simplifies to<br />
R(M) = CMv, (13)
predictsd<br />
7<br />
B<br />
a a<br />
t<br />
I<br />
I<br />
r 1 J .<br />
t/ f.<br />
. o './.'<br />
t 'y't<br />
.,r i<br />
J<br />
t<br />
.|F:.<br />
1 2 3 4 6 6 7<br />
R obrur"ud<br />
Figure 1. Predicted Driver Fatality Risks (Table 4) Vereuc<br />
Values Estlmeted from Fatalfty Ratloe (Table 3) for<br />
MY > 1980 Care<br />
1.8<br />
1.7<br />
1.6<br />
1.6<br />
1.4<br />
1.3<br />
R 1.2<br />
prcdlctod<br />
1.1<br />
R<br />
observed<br />
o,9<br />
o.8<br />
o.7<br />
a<br />
a a<br />
I<br />
1 t<br />
t<br />
I r -t,ttj'<br />
- t<br />
t<br />
t<br />
a t t a t r t t a '<br />
1,..t -<br />
..aa<br />
.<br />
a<br />
a a<br />
pr6dictEd<br />
tt ,<br />
E 6 7<br />
Flgure 2. ftedlcted Driver Fatality Rhkr (Tabte 4) Helative<br />
to Valuer Eetimated from Fatality Ratlos (Iabte 3) Versu$<br />
the Predlcted Value lor MY e 1980 Cars<br />
where all the mass-independent factors have been<br />
included in the one constant C. In terms of the<br />
illustrative example of 900 kg cars crashing into 900 kg<br />
cars compflred to 1800 kg cars crashing into 1800 kg<br />
cars, eqn l2 with Y = -0.322 gives that the driver fatality<br />
risk in the lighfllight car crash is 25Vo greater than in the<br />
heavy/heavy car crash- This is much less than the factor<br />
of two found for substantially older model-year cars by<br />
Evans and Wasielewski [1987].<br />
Effict of tar mass when crashing into an essenrially<br />
infinite mass<br />
As m, becomes large, further increases in m, have<br />
ever decreasing influence on thc probability that the<br />
Sect on 3: Technlcal Sessjons<br />
driver in the first car is killed. Thus, in the limit of<br />
crashing into very largc cars, the asymptotic bchavior of<br />
eqn 9 gives that thc filtillity risk to the drivcr in the first<br />
car, f(m,), depends on the first car)s mass according to<br />
f(m,)=Gfilrv, (14)<br />
where c includes all the mass-independent terms. The<br />
finding that the dependence of driver fatality on the mass<br />
of the car in which thc driver is travelling is the same<br />
for crashes into idcntical cars as for crashes into<br />
hypothetically extrenrely heavy cars is in keeping with<br />
the often made analogy bctween a barrier crash test and<br />
two idcntical cars crashing into cach other.<br />
Effect on syilem safery when a car is replaced by one of<br />
different mass<br />
Let us suppose thnt fln individual driver rcplaces a<br />
present car with onc of a different rnass. For cxpository<br />
convenience, let us describe the proccsscs in terms of a<br />
driver replacing a presently used car by one of lower<br />
mass, although all the equations derived apply for<br />
changes in either direction.<br />
When a driver replaces a pre$ent car by a lighter one,<br />
that driver's fatality risk incrcascs in a two car-crash,<br />
regardless of the mass of the othcr involved car. On the<br />
other hand, the fatality risk for the other driver declincs,<br />
as il consequence of crashing into a car that is lighter.<br />
These effccts arc firmly established by many studics,<br />
including thc prcsent one (eqn 9), and arc so compellingly<br />
suggested by physical intuition that they should be<br />
regarded as essentially<br />
"laws"<br />
[Evans l99ll Evans and<br />
Frick 199lal. A question that is much more complex,<br />
and for which physical intuition offers little guidancc, is<br />
"Whcn g driver transfers to a lightcr car, is this driver's<br />
increase in fatality risk larger or smaller than the risk<br />
reduction to other drivcrs?" In other words, when an<br />
individual driver transfbrs to a lighter car, does this lead<br />
to an increase or decrease in net fatality risk.<br />
Equation 9 gives the fatality risk for the first driver<br />
when that driver's car crashes into another cff; the<br />
equation is from the perspective of thc first drivcr. By<br />
transposing m, and m, and adding, we estimate the<br />
fatrlity risk to both drivcrs combined, T = T(mr,mJ, as<br />
T(m,,mr) = {m,v [l - exp (G x p*)]<br />
+ mrv 1l - exp (G x F 'w)l)/k . (15)<br />
If the first driver replaces an initial car of mass m, by<br />
another of different mass nt r', then a new net fatality risk<br />
to both drivers, T', is calculated by substituting m,' for<br />
m, in cqn 15 (and also using cqn 7 to compute a new<br />
mass ratio). It is convenient to considcr thc fractional<br />
changc, P, in T when a car is replaced by one of a<br />
diffcrcnt mass, given by<br />
P = [T'- T]/T = T'lT - 1. (16)<br />
:
13th lnternetlonal Technlcal <strong>Conf</strong>erence on Experlmental Satety Vehlcles<br />
If the new mass is some fraction, d, less than the old<br />
mass, defined by<br />
m,'= (l - d)m, ,<br />
(17)<br />
then P does not depend explicitly or ln1, but only on the<br />
initial mass ratio and the fractional decrease, d, in the<br />
mass of the first car. From eqns 15-17 we dcrive<br />
where<br />
and<br />
P-<br />
I*)'-exf,Gyt-y%*{ft')<br />
I + x" - exflGr") - x "exflGx *)<br />
x=l/F<br />
y = (l-d)x .<br />
- 1<br />
(18)<br />
Figure 3 shows P/d plotted versus d for illustrative<br />
values of d. When d is small (say less than about 0.05),<br />
P/d is essentially independent of d. To clarify the<br />
interpretation of P/d let us focus on d = 0.01, or l7o,<br />
(highlighted in bold), keeping in mind that this same<br />
relationship applies to any change in the mass of the first<br />
car, provided it is not more than about 57o. Suppose an<br />
initial scenario of two 1500 kg cars crashcd into each<br />
other is comparcd to a new scenario in which one of<br />
these cars is replaced by a car l5 kg lighter. Reading the<br />
graph at F = I shows that the combined fatality risk<br />
increases by 0,l6Vo.If thc first car had become lighter<br />
by 7.5 kg (0.5%) or 30 kg (27o) instead of 15 kg, then<br />
the net increase in fatality risk would have been 0.08Vo<br />
and O.32Vo, rcspectively, but the percent change in net<br />
fatality risk per percent change in the mass of the first<br />
car would remain constant al 0.l6vo. As d becomes<br />
larger, these relationships of proportionality no longer<br />
hold-hence thc curves for higher values o[ d.<br />
If the car$ in the example had been 800 kg cars, with<br />
one becoming 8 kg lighter, thc same 0,160/o increase in<br />
fatality risk would apply. However, as the initial risk is<br />
higher for two lighter cars crashing into each othcr, this<br />
would he O-l6Vo of a larger quantity, so a larger increasc<br />
in net absolute fatality risk would rcsult.<br />
For d = lVo,the largest net filtality increase of 0.34Vo<br />
occurs at p = 0.56. Some combinations of initial car<br />
masses generate net fatality reductions, thc largest of<br />
these being a net fatality change of -O.OZTI at p = 1.77.<br />
Thus, replacing a 1000 kg car crashing into a 1770 kg<br />
car by a 990 kg car crashing into a 1770 kg car generates<br />
a net fatality reduction of O.OZVo. This net risk reduction<br />
arises because the increase in fatality risk to the driver<br />
in the car of rcduced mass is smaller than the reduction<br />
to the other driver.<br />
The other curves cover cases in which cars are<br />
replaced by ones of substantially differcnt mass. In all<br />
cases the value for F = I is positive; that is, if two cars<br />
are of identical mass, replacing one by another lighter by<br />
any amount always increases net driver fatality risk.<br />
88<br />
(le)<br />
(20)<br />
o.45<br />
0.40<br />
o.35<br />
o.30<br />
0.25<br />
0.20<br />
0.15<br />
0.10<br />
0.o6<br />
0.00<br />
Percent change in net fatelity risk<br />
PercBnt reduction in mass of first car<br />
-0.05<br />
0.4 0.6 0_8 r 1.2 1.4 1.6 1.8 2 2,2<br />
Mass ratio, Pr<br />
The curves are computed using eqn 18 with parameters for<br />
MY > 1980 cars.<br />
Flgure 3. Hsw Net Driver Fatallty Hlsk Changes When<br />
a Driver in a Sublect Car Transfers to a Cat Lighter by<br />
dclo Versus the Ratio, p, of the Mass of the Other Car<br />
to the Original Mass of the SubJect Car<br />
Thus if we have a population of identical cars of any<br />
mass, replacing any one of thcm by a lightcr car will<br />
always increase population fatality risk.<br />
Rctluctions in fatality risk occur from some<br />
combinations of mass ratio and percent reduction in the<br />
mass o[ the first car (provided it is not grcatcr than<br />
30%). However, the greater magnitude of positive<br />
values, and their overwhclming preponderance over<br />
negative values in Figure 3 shows lhat rcplacing any real<br />
car population by another containing gcnerally lighter<br />
cars will always increase the total numbor of drivcr<br />
fatalities if othcr factors are equal.<br />
Because the values plotted in Figure 3 reflect small<br />
differences between two rclatively large quantities, they<br />
are highly dependent on thc precise values of the large<br />
quantities, and hence on thc values of the parameters,<br />
eqns l0-12. Because of the already considerable complexity<br />
in Figurc 3, it is not feasible to present an<br />
analytical sensitivity analysis. Choosing a numbcr of<br />
catcgorics othcr than I considerably affects Figure 3, as<br />
does fitting the data to functional forms other than eqn<br />
9. However, even though the details vary substantially,<br />
the general finding thflt net fatality risk increases when
m, declines for most values of p, and that declines are of<br />
larger magnitude than the few increases that occur, are<br />
findings common to all of many ditterent analyses<br />
performed. Thus, the general conclusions are fairly<br />
robust even if specific details in Figure 3 are not.<br />
Does making all cars the same mass reduce risk?<br />
Let us consider a crash between two cars of the same<br />
mass, M = 800 kg. The risk to each driver is calculated<br />
from eqn 9 as 4.164, for a total risk of 9.32g (in<br />
arbitrary units). If one of the cars becomes am = 100 kg<br />
heavier, and the other am lighter (thus preserving the<br />
same 800 kg average mass), eqn 9 computes risks of<br />
5.566 and 2.737 for the drivers of the 700 kg and 900 kg<br />
cars, respectively. The new total risk of 9.303 is 0.37o<br />
less than for the equal mass case. Repeating for different<br />
values reveals a reduction in net risk for all fea.sible<br />
values of am in conjunction with any value of M.<br />
Given that transforming equal mass cars into unequal<br />
mass cars (while preserving avcrage mass) always<br />
decreases dsk, it follows that the opposite process will<br />
always increase risk. This implies that, assuming the<br />
average mass of a car population is to be set at some<br />
value, the distribution which provides the highest net<br />
fatality risk is the one in which all thc cars are of<br />
identical mass. Although making all cars of equal mass,<br />
while keeping the average mass constant, will lead to a<br />
more equitable distribution of risk, it will also increase<br />
fatalities.<br />
Eqn t has many applications beyond those illustratcd<br />
above, including determining the total risk in a car<br />
population with a given distribution by mass. This<br />
enablcs changes in risk to be computed when the<br />
distribution by mass changes as nright happen if cars iue<br />
systematically replaced by lighter ones.<br />
Results for Cars of all Model Years<br />
By using all model year cars containcd in the FARS<br />
data for 1975 through 1989, much larger snmple sizes<br />
are obtained, as shown in Tablc 5 for data in 12 mass<br />
categories. The total number of crashes contributing to<br />
Table 5 is 41,755, compared to 5,470 for Table l; so<br />
even though there are 144 cells compared to the former<br />
64, there are still more fatalities per cell. Apart tiom the<br />
greater number of categories, the analysis proceeds<br />
exactly as before, with thc rcsults in Tables 5 - 8.<br />
(compare to Tahles I - 4) and Figures 4 - 6 (comparc to<br />
Figures I - 3).<br />
The parametcrs of the fit of eqn 9 to the data in Table<br />
7 are<br />
V=-1.15910.056<br />
G=-L100t0.082,and<br />
W=2.132 10.037.<br />
(21)<br />
(22)<br />
(23)<br />
,,<br />
,<br />
Sectlon 3: Technlcal $essions<br />
Tabb 5. The Number of Drlver Fatatltler In Cer I<br />
(wlth maw In the lth maEa crtegory) When Thls Car le<br />
in Collision with Car | (mass in the lth mass category)<br />
rl<br />
fi<br />
rB<br />
r,l<br />
r5<br />
|6<br />
17<br />
,8<br />
ro<br />
rll<br />
11 u2 13 e,t rS |6 e7 rB q9 flo rtl r12<br />
ft! .lso *r B7e 472 536 ,re8 ssa E6s 6,io 63e 64e<br />
168 12601 338 S38 ,t3l ,tsl 432 48c 61' 560 5o4 660<br />
166 210 13521 365 391 408 167 {86 171 1e1 4Et 608<br />
117 t68 221<br />
| 331 330<br />
|<br />
352 438 3e3 506 473 4,t6 479<br />
at 1s7 209 282<br />
| 2ds I ilz st2 3s{ 4sz ,fB6 d44 Fo?<br />
lm 1dl r'z ra aos fi-<br />
I 741 310 333 383 ,tO3 441 167<br />
72 106 187 let z2o res<br />
leael<br />
36r{ BEo Bgs 3EB ,fo3<br />
Bt 86 rg8 14s 1s6 flt zre lrzof szr 378 406 4oE<br />
,f6 s4 e6 r.r rsr re7 zr+ r*- Eiil gre 361 36rl<br />
,rr 6,r s,r ro7 166 res rsr ,ru rlo- lett-'l ,., 310<br />
,fE E0 65 c? 130 163 Llr zzt zt+ zn frsil ,u,<br />
32 Ba 6E ,, loo rzs llg rE6 ug ,nn '# E*l<br />
Thc rvcregt srn of thc ll ns crtrCorltl rrr:<br />
rl : 834 kE. rE = 1294 1r.<br />
t2 e 060 kg; ffi q IBOT kO;<br />
w3 = 1085 kg; 17 = 1463 k9.<br />
14 r 1181 kg; 18 r 1b6O kg.<br />
r'9 = 1643 kO;<br />
rl0 = 1747 kq;<br />
!11 = 1867 kg.<br />
wl? - 2076 kg.<br />
Oata for all model year cars, FARS 1S7S through 1g8g.<br />
Table 6. The Number ol Single-Car Crashes in Which<br />
at Least One Pedestrian Was Killed Segmented into tho<br />
Mass Categoriss Ussd in the Driver Fatality Analysis<br />
Category<br />
1<br />
2<br />
3<br />
I<br />
5<br />
6<br />
7<br />
I<br />
I<br />
10<br />
l1<br />
L2<br />
lfuss, kg<br />
ll i n inum l{ex i.rum Average<br />
655 .0<br />
8$8.1<br />
1090. 1<br />
LL32.2<br />
L227 .1<br />
1363. r<br />
1424 .3<br />
1509. I<br />
1600 .3<br />
1686 .0<br />
1800.3<br />
1933.2<br />
857.7<br />
7029.7<br />
t13l.7<br />
1227.O<br />
1362.6<br />
1423.8<br />
1508 .7<br />
1599 .4<br />
1685 .6<br />
1799.4<br />
1932.3<br />
2606 .4<br />
834.O<br />
960.0<br />
1084 .9<br />
llSl .3<br />
129/t .4<br />
1397 .3<br />
1463,2<br />
1560 .0<br />
1643,4<br />
L717 .1<br />
1867 . I<br />
2076.4<br />
Numbcrof Crashes<br />
3081 = E(1)<br />
3325 = E(2)<br />
36s8 = E(3)<br />
3816 = E(4)<br />
ao62 = E(6)<br />
4323 = E(6)<br />
45s1 = H(7)<br />
a830 = E(8)<br />
4e24 = E(e)<br />
52s3 = E(10)<br />
5363 = E(lr)<br />
6272 = E(L?)<br />
Data for all model y6ar car6, FAFTS years 1975 through 1999.
13th lntemetlonel Technlcal <strong>Conf</strong>en<br />
Table 7. Ths Fatsflty Risk to a Driver In Gar I When Thls<br />
Gar Crashes into Car I, Each Car Being in the Categoty<br />
wlth thE lndlceled Average Mass<br />
cg.<br />
Carj*<br />
r10 wII<br />
lf'-"--1<br />
rt ll8.13l 12.4 r7.7 16.4 r9.1 20.,1 18.0 19.0 18.8 ls.9 ls.7 20.3<br />
*r lu-er lri]l ro.t 18.,r 16.z r?.3 l?.s ls.s tE.o ld.z l,t.4 15.0<br />
I |-r------.1 L-Jw3<br />
7.03 8.76 12.9 13.4 13.0 13.e 13.1 13.3 13.0 11.0 13.3<br />
| 113.11<br />
| - F - - - - - - - ]<br />
14 s.0s 6.s2 8.16 tj.1. 10.8 12.8 10.8 13.7 l1.e 1r.1 1?.1<br />
| tl.j]<br />
*s I<br />
s.sr s.eo 7.14 i,i<br />
fa<br />
e.oa B.s7 e.,fz 11.8 rr.E to.4 tl.e<br />
*u t.tt 4.eB s.B4 u..o lE s.zs 8.10 e.ls B.e,r e .?4 10.4<br />
I li*l<br />
17 I2.61 3.66 6.70 5.79 6.04 "* F;l 8.17 7.93 8.20 7.46 8.53<br />
l u -<br />
$r8 2.72 3.s6 ,t.08 6.06 8.13 6.6r 7.61 7.s7 8.o7<br />
12.20 t.*l =<br />
*r<br />
I<br />
t.u. r.67 a.68 3.6? 4,oe ,t.70 4.BE tJ4 d.21 6.eE 7.12<br />
F.rsl<br />
-tol t.rr 1.86 2.46 2.60 s.68 ,r.28 s.B,r t.ut lJ7<br />
llrtl<br />
..tu, u.uo<br />
vrrl r.sa r.68 r.68 2.rg s.os s.EB s.E6 ,t.,16 4.61 Lss o.ou<br />
F36]<br />
rrl E<br />
o.e' r.4E r.04 2.88 r.71 i.B, 3.lr 3.3s s.B, o* F;<br />
' Tho rvorlge moseee ol thc 12 mrt crtagorict arc:<br />
All values are relative to a value one for the lovvest risk case. that<br />
faced by a driver of a car in the heaviest mass category crashing<br />
into a car in the lightest mass category. Note that the ri$k for the<br />
lowest risk case here is not the same as in Table 3, Data for all<br />
model year cars, and FARS 1975 through 1989.<br />
Table 8. Driver Fetality Risks Computed Using Eqn Twith<br />
the Paremeters for Cars of All Model Y6€rs in Eqns 21-?3<br />
rl<br />
u2<br />
rd<br />
wB<br />
s.38<br />
6.80 8.33<br />
5-39 6.6S 7.S3<br />
,{. 16 6 .2,1 6 .30 OE<br />
83<br />
l4<br />
ll.7 12.1 12.8<br />
74 10.5 10,9<br />
60<br />
63 9.0,1<br />
rg [10<br />
19.6 19.7 19.7 10.8<br />
3 16.5 16.6 16.8<br />
.6 13.9 14.2 14.4<br />
.8 r?.2 12.6 12.9<br />
.98 10.4 10.8 11.3<br />
58 e.08 9.,f6 10.0<br />
7S 8.24 8.69 9-30<br />
2.41 3.10 t|.81,1.36 5.(x) 6.56 5.01 6.77 7.n 7.67 8.31<br />
w9 ?.06 2.66 3.29 3.78 4.38 4.87 5,19 6.64 6.44 6.89 7.5,0<br />
*ol t.tt 2.zz 2.76 3.re 3.69 4.rs ,r.,{,r o.tu lro-E,lg u *<br />
vl1l 1.3e 7.a2 2.27 2.64 3.08 3.48 3.73 ,f.10 4.41 4.78 l5.rgl 5.82<br />
il 1.gl 1.66 L.gB 2.27 z.Eg 2.7s s.os B.86 3.66 {.ol<br />
t Thc evcrego nas*e* of thc l2 msaa crt.gori.t rrc:<br />
90<br />
11 = 834 kr; wS = 120/t ks;<br />
12 = 960 kg; 16 = 13S7 kg;<br />
w3 = 1085 k9; 17 = 1463 kg;<br />
yl ! 1181 kt; 18 = 1580 kg;<br />
st = 83,1 kg; w5 i 1294 kg;<br />
s2 = 960 kg; 16 ! 13s7 kg;<br />
13 + 1085 kg; 17 - 1463 kg;<br />
14 = 1181 kg; 18 = 1560 kg;<br />
6,1<br />
rg = 1643 |(g;<br />
r10 = 17'17 kg;<br />
rll , 1867 kO;<br />
r12 E 2076 kg.<br />
.1<br />
r0 = 16,13 kg;<br />
r10 = 17'17 kg;<br />
r11 = 1887 ks;<br />
r12 = 2076 kg,<br />
erlmental safety vehlcles<br />
R predicted<br />
R observed<br />
Figure 4. Predicted Driver Fatality Risks (Table 8) Versus<br />
Values E$timated from Fatality Ratios (Table 7) for Cars<br />
of All tVlodel Years Combined<br />
1.7<br />
1'B<br />
1.6<br />
1.4<br />
1.3<br />
1.2<br />
predicted 1.1<br />
R obrer"ed<br />
0.9<br />
o.8<br />
o.7<br />
10<br />
, a<br />
ot t<br />
' a t<br />
-<br />
t<br />
a -t<br />
aa<br />
arl a<br />
t<br />
- r i r l r<br />
' . _:..tj.rir..jdi<br />
a.f.- t+|llhg.<br />
.<br />
rr<br />
t -r'i t'r l r<br />
t . . t . t * . . r t<br />
a<br />
B predicted<br />
Figure 5. Predicted Driver Fatality Risks (Table 8) Relative<br />
to Values Estimated from Fatality Ratios (Iable 7) Versus<br />
the Predicted Value lor Cars of All Model Years<br />
Combined<br />
The main difference between these parameters and<br />
eqns l0-12 for MY > 1980 cars is the larger value of V.<br />
Substituting this into eqn l3 gives that the driver fatality<br />
risk for two 900 kg cars crash into each other is 2.2<br />
timcs thc value for two 1800 kg cars crashing into each<br />
a<br />
a<br />
a<br />
10<br />
a<br />
26<br />
26
other, compared to an earlier estimate also equal to 2.2,<br />
(Earlier work, including a diffcrcnt analytical fit to<br />
two-car crash data by Joksch tl983l, is summarized by<br />
Evans [99], p. 6a-78]). Eqn 14 estimates this same 2.2<br />
factor for the ratio of fatality risk in a 900 kg car<br />
crashing into a car of infinite mass compared to an 1800<br />
kg car crashing into a car of infinite mass. This may be<br />
compared to a ratio of 2.4 between the risk in a 900 kg<br />
car in a single-vehicle crash to the risk in an 1800 kg car<br />
in single-vehicle crashes.<br />
Figure 6 shows that for the ca$e of all model year<br />
cars, a driver transferring from a car of any mass to a<br />
car of mass lower by any amount always generates an<br />
increase in net fatality risk. This applies to "average"<br />
cars from the distribution on which the analysis is based.<br />
Percent change in net fatality risk<br />
Percent reduction in mass of first car<br />
ffirAii<br />
o.4 0.6 0.8 1 1.2 t 4 l.e 1.S 2 2.?<br />
Mass ratio, 1,r.<br />
The curves are computed using eqn 18 with parameters<br />
lor cars<br />
of all model years combined.<br />
Figure 6. How Net Drivsr Fatality Risk Changes When<br />
a Driver in a Sublect Car Transfers to a Car Lighter by<br />
d% Versue the Ratio, p, of the Mass of the Other Car<br />
to ths Orlglnal Mase of the Subject Car<br />
Why ts the mass effect less of the newer model year<br />
cars?<br />
Some preliminary analysis were performed to attempt<br />
to understand bctter why the results for MY l 1980 cars<br />
are so different from those for all cars. While it is not<br />
possible to perform the entire analysis in narrower<br />
segmcnts of model year than those used, the relationship<br />
Sectlon 3: Technlcal Sessions<br />
between fatality risk and mass ratio was examined in<br />
finer deliril with the results shown bclow:<br />
Average MY<br />
1 973<br />
1974<br />
1 97s<br />
1 976<br />
1977<br />
1 978<br />
1 979<br />
1 980<br />
1 981<br />
1 982<br />
1 983<br />
1 984<br />
1 985<br />
1 986<br />
1 987<br />
1 9BB<br />
1 989<br />
Risk in 900 kg car<br />
Risk in 1800 kg car<br />
10<br />
12<br />
17<br />
16<br />
19<br />
12<br />
11<br />
' 9<br />
I<br />
7<br />
6<br />
5<br />
6<br />
7<br />
7<br />
11<br />
12<br />
The interpretation is as follows. The entry for 1980<br />
(say) was dcrived by considering all crashes involving<br />
MY l9tt0. as well as MY 1979 and MY l98l cars<br />
crashing into any other car in these same threc modcl<br />
year categories, centered at MY 1980. Thcsc crashes<br />
were used to determine the relationship bctwccn rclative<br />
driver fatality risk and mass riltio (eqn 5 of Evans and<br />
Frick [l991a]). Substituting mass ratio (p) = 2 givcs the<br />
values shown for the drivcr fatality risk in a 900 kg car<br />
compared to in an 1800 kg car when these cars crash<br />
into each other.<br />
What appears to be happening is that the strength of<br />
the mass effect declined for cars built in the mid-1980s,<br />
reaching a low round about MY 1984 (recall that for the<br />
MY : 1980 analysis, the average model year was 1983.4,<br />
and for the all MY analysis, 1976.2). The dccline in the<br />
strength of the mass effect for the early 1980s models<br />
may be because smaller cats in that pcriod wcrc more<br />
likely to have undergone more substantial redesign than<br />
larger cars. Thus crashes between small and large cars<br />
did not only involve dilferences in mass, which provided<br />
increased protection to occupilnts in heavier cars, but<br />
differences in extent of redesign, which increased the<br />
protcction of occupants in the more redesigned lightcr<br />
cars. As larger cars were later subject to morc redesign,<br />
such differential dcsign diffcrcnces would have diminished,<br />
so that mass again became the more exclusive<br />
factor, leading to the relationship with mass becoming<br />
more like what it was for the earlier cars. If this<br />
tentative intcrpretation is correct, the conclusions based<br />
on the MY > 1980 cars mily undercstimatc the strength<br />
of car-mass effects in future fleets.<br />
Discussion<br />
/s ir mass, or some correlate of mass, such as size?<br />
All the relationships in this paper havc been in terms<br />
of mass. Yet mass is strongly correlated with other<br />
9l
13th lnternetional Technlcal Conterence on Experimental Satety Vehicles<br />
characteristics of a car, especially its size. We examined<br />
two crash types in which mass, as such, should not play<br />
an important role. These are crashes between cars of<br />
similar mass, and cars crashing into other cars of<br />
esscntially infinite mass. For both crash types we find<br />
higher driver fatality risks in lighter cars. In the most<br />
simple dynamical model of these crashes, mass does not<br />
affect any vchicle trajectory. Thus any effect dependent<br />
on mass likely reflecls some other property of the<br />
vehicle, such as its size.<br />
A further indication that mass is not the physical<br />
factor influencing risk in these two crash types is that<br />
newer cars exhibit a smaller mass dependence than do<br />
older cars. (Compare eqns 13 and 14 with the values of<br />
V given by eqns 10 and 21). In contrast, the much liuger<br />
differences in fatality risk that occur when cars of<br />
dissimilar mass crash into each other appears intrinsically<br />
related to ma$s, and to the differences in speed<br />
change required by Newton's laws of motion.<br />
The vehicle factor producing the correlations with<br />
mass in the two crash types f-or which mass should not<br />
play a major role is likely to be vehicle size. Increased<br />
vehicle size makes more crush space available to manage<br />
energy, and more space in which to ride down the crash.<br />
However, recent studie$ [Evans and Frick l99lbl find<br />
that mass is substantially more important than size in<br />
determining outcome. When cars of the same wheelbase<br />
but different mass crashed into each other, the driver in<br />
the lighter car wfls more likely to be killed Lhan was the<br />
driver in the heavier car. When cars of similar mass but<br />
different wheelbase crashed into each other, any effect<br />
due to differences in wheelbase was too small to be<br />
detected by the same method that demonstrated clear<br />
effects dependent on car mass.<br />
Can lighter smaller cars be made as safe as larger<br />
heavier t:ars?<br />
Vehicle mass and vehicle size each influence safety in<br />
crashes in differcnt ways. Their influences are important<br />
in single- and in two-car crashes. In a crash into an<br />
immovable infinitely hard barrier, mass does not affect<br />
vchicle dynamics, and should thereforc not much affcct<br />
outcome, whcrcas increascd size can bc used to make<br />
available more space for energy management and ride<br />
down. Howevcr, most struck objects arc not likc barricrs,<br />
but instead may bend, distort, break or move. The extent<br />
to which they do so reduces the striking vehicle's speed<br />
change and consequent frrrces on occupants. The greater<br />
the mass of the vehicle, the less are these potentially<br />
injury producing forces.<br />
Occupant protection devices can improve safety for<br />
smaller cars, but if applied also to larger cars will<br />
likewise improve safety. Specific information is available<br />
for the case of safety bclts. Three studics lEvans 1985;<br />
Evans and Frick 1986;1991a1, each using different<br />
mcthods and indepcndent dtta all find that lap/shoulder<br />
belts provide an approximately equal reduction (of about<br />
92<br />
42Vr\ in driver fatality risk, independent of the size of<br />
the car Because the base risk is larger for the smaller<br />
car, the absolute benefit of belt wearing is greater in the<br />
smaller car, but the studies find no difference in the<br />
proportionate reduction.<br />
When averaged over either single-vehicle or over<br />
two-vehicle crashes the following generalizations appear<br />
to be beyond reasonablc disputc:<br />
. If all other factors (including size) are the same, the<br />
heavier the vehicle, the lower the occupants' risk in a<br />
crash.<br />
. If all other factors (including mass) are the same, the<br />
larger the vehicle, the lower the occupants' risk in a<br />
crash.<br />
In the above, all other factors being the same includes<br />
the assumption that stiffness scales with mass.<br />
Relation to fuel economy stilnddrds (CAFE)<br />
Incrcasing car mass increases fuel use as a consequence<br />
of increased rolling resistance and, during acceleration,<br />
increased incrtial forccs. Incrcasing car size<br />
incrcascs fucl use because of increased aerodynamic<br />
drag, but this effect tcnds to be smaller than that due to<br />
mass. Motivated by a desire to reduce personal fuel use,<br />
many drivers have transferred to lighter, smaller cars.<br />
Corporate Average Fucl Economy (CAFE) standards<br />
have been adopted with the goal of rcducing fucl usc at<br />
the national level. Following thesc changes, the average<br />
mass of cars in thc US car population declined.<br />
Many previous studies, especially the recent one by<br />
Evans and Frick [l991a], find that when othcr factors are<br />
equal, a driver transferring to a lighter car incurs an<br />
incrcased risk of being killcd in a crash. The prcsent<br />
study shows that when all cars in a fleet become lighter,<br />
overall system fatality risk frorn two-car crashes<br />
increases. The equation derived by Klein, Hertz, and<br />
Borencr tl99ll from state injury data leads to the same<br />
conclusion. A fleet of identical lighter cars is less safe<br />
than a fleet of identical heavier cars.<br />
Changes that reduce fuel use may increase or decrease<br />
safcty. For example, the -55 mph spccd limit, introduced<br />
to save fuel, also increased safety. Indeed, its cffccl on<br />
safety was larger than that on fuel use bccause,<br />
approximately, fuel consurnption per unit distancc of<br />
travel is proportional to spccd, whcrcas fafality risk is<br />
proportional to speed to the power four [Evans 199 I, p.<br />
1541. Many factors in addition to cflr mass and size<br />
influence safety, and it is clearly possible for a lighter<br />
car to be safer than a heavier one if the cars differ in<br />
other features important for safety. However, if the same<br />
safety features are incorporated into each of the cars, the<br />
larger heavier one will always be safer.<br />
Keeping mass constant, and increasing car size by, for<br />
example, using lowcr dcnsity construction materials, will<br />
reduce occupant risk at only a modest fuclusc pcnalty,<br />
However, in a fleet consisting exclusively of cars made<br />
from lower dcnsity material, thc lighter cars in the flcct
would still be at greater risk than the heavier cars, If the<br />
lower density matcrial were instead used to rcduce the<br />
mass of all cars whilc keeping their sizes fixcd, this<br />
would reduce fuel with no obvious influence on risk in<br />
two-car crashes. Risk could increase or decrease<br />
depending on such engineering details as matcrial<br />
stiffness. Although there is no simple physical reason<br />
why risk in two-car crashes should change if cars<br />
became lighter without changing size, there are<br />
compelling physical reasons why single-car crash risk<br />
would increase. Struck objccts may move, dent, or break,<br />
and their tendcncy to do so increase with increasing<br />
mass of the sriking vehicle, thereby providing increased<br />
protection to occupants as mass increases. It appears that<br />
whatever change is applied uniformly to all cars will<br />
always leave the driver of a lighter car at grcater net risk<br />
than the driver of a heavier car when other factors are<br />
the same. A similar comment applies for car size, and<br />
both comments apply to fleets of cars as well as to<br />
individual drivers.<br />
The finding that an individual transferring to a lightcr<br />
car increases that individual's fatality risk, or that<br />
society choosing lighter cars leads to incrcased net<br />
tratfic fatalities, does not determine what mass vehicle<br />
any individual or society should choose. Such choices<br />
involve the balancing of many factors in addition to<br />
safety. When all othcr factors are the same, heavier or<br />
larger vehicles offer intrinsically more occupant<br />
protection in ways that cannot bc negated by vehicle<br />
design changes applied to all vehiclcs, or by material<br />
substitutions in all vehicles. Thc rclationships between<br />
mass/size and both safety and fuel consumption is<br />
perhaps analogous to the relationship betwcen safety and<br />
speed. There can be little doubt that an individual driver<br />
increases risk by travelling faster, and that society<br />
increases nct societal risk by choosing higher ralher than<br />
lower spced limits. It follows thflt the safest traffic<br />
system consists of exclusively gargantuan massive<br />
vehicles moving at near zero speeds. Such a system<br />
offers little to fulfill the primary goals of transportation,<br />
even if it greatly diminishes the undcsircd by-product of<br />
losses from trflffic crashes. Any individual or societal<br />
decision on such questions should be bascd on balancing<br />
of the known effects.<br />
Conclusions<br />
. An analytical function fitted to fatality data shows<br />
that net driver fatality risk (or nct fatalities) for a car<br />
population is increased if:<br />
- Any car in thc population is replaced by a lighter<br />
one<br />
- One population of identical cars is replaced by<br />
another population of lighter identical cars<br />
- The car population becomes of uniform mass while<br />
maintaining the averagc mass constant<br />
. Thc salety disadvantage of lighter and smaller cars<br />
is intrinsic-it cannot be negated by design changes<br />
Sectlon 3: Technlca/ Sessions<br />
if thes€ are also available to larger heavier cars<br />
bccause, when all other factors are equal, mote mass<br />
and more space can be used to provide increased<br />
safety.<br />
. Fuel economy and safety (like higher speed limits<br />
and safety) are intrinsically in conflicq individual<br />
and national choices require a balancing of<br />
advantages.<br />
Acknowledgments<br />
Valuable inputs from James A. Bennett, Daniel P.<br />
Faust. Robcrt A. Frosch, Dana B. Kamcrud, Harold J.<br />
Mertz, Jr., and David C. Viano contributed greatly to this<br />
project and are gratcfully acknowledged. Helpful<br />
discussions with Robert M. Goor and Gary C. McDonald<br />
regarding the possibility of analytically dctermining the<br />
extrema of eqn 9 are gratefully acknowledged.<br />
References<br />
Joksch, H.C. Light-weight car safety analysis, phase II,<br />
part II: occupant fatality and injury risk in relation to car<br />
weight. Perf'ormed under contract CEM-8102C1160,<br />
Center for the Environmcnt and Man, Hartford, CT; June<br />
1983.<br />
Evans, L. Driver fatalities versus car mass using a new<br />
exposure approach. Accident Anulysis and Prevention<br />
l6:19-36: 1984.<br />
Evans, L. Fatality risk for bclted drivers versus car mas$.<br />
Accident Analysis and Prcvention l7:251-271; 1985.<br />
Evans, L. Traffic Safety and the Driver. New York, NY:<br />
Van Nostrand Reinhold: 1991.<br />
Evans, L.; Frick, M.C. Safcty belt effectiveness in<br />
preventing driver fatalities vcrsus a number of vehicular,<br />
accident, roadway and environmental factors. Journal of<br />
Safety Research l7:143-154; 1986.<br />
Evans, L.; Frick, M.C. Mass ratio and relative driver<br />
fatality risk in two-vehiclc crashes. General Motors<br />
Research Publication GMR-7419, 29 July 199la.<br />
Evans, L.; Frick, M.C. Car siee or car mas$-which has<br />
greater influence on fatality risk?, General Motors<br />
Research Publication GMR-7462, 30 August l99lb.<br />
Car size or car mass-which has greater influence on<br />
fatality risk'I, Leonard Evans and Michael C. Frick,<br />
General Motors Research Publication GMR-7462, 30<br />
August 1991.<br />
Evans, L.; Wasielewski, P.F. Serious or fatal driver<br />
injury rate versus car mass in head-on crashes betwecn<br />
cars of similar nrass. Accident Analysis and Prcvcntion<br />
l9:l l9-l3l: 1987.<br />
Klein. T.M.: Hcrtz, E.; Borener, S. A collection of recent<br />
analyses of vehicle weight and safcty. Washington, DC:<br />
National Highway Traffic Safety Administration, rcport<br />
DoT HS-807767, May 1991.<br />
National Highwrry Traffic Safcty Administration. Fatal<br />
Accident Reporting System 1989. Document DOT HS<br />
807 693. Washington, DC; March 1991.<br />
93<br />
q<br />
il!<br />
.<br />
,::<br />
:1<br />
,I'<br />
:n
13th lntematlonel Technlcal <strong>Conf</strong>erence on Experlmental Safety Vehicles<br />
st-o-tl<br />
A Collection of Recent Analyses of Vehicle Weight and Safety<br />
Terry M. Klein<br />
Ellen Hertz, Ph.D.<br />
Sherry Borener, Ph.D.<br />
National Highway Traffic Safety<br />
Administration<br />
Abstract<br />
This report documcnts the results of an analysis of the<br />
effect ofcar weight on safety. The analysis encompassed<br />
a number of crash modes including fatality risk in singlevehicle<br />
nonrollover crashes, serious injury and fatality<br />
risk in car-to-car crashes, and serious injury risk in<br />
collisions of cars with medium/hcavy trucks. This work<br />
was undcrlaken as part of an effort to study the longterm<br />
effects of the major reductions in passenger car<br />
weight of the 1970's and 1980's.<br />
Data from the State of Texas for accident years 1984<br />
through 1987 and the State of Maryland for accident<br />
years 1984 through 1988 were used. The analysis<br />
employed logistic regression methods to modcl the<br />
(conditional) risk of serious injury as a l'unction ol' a<br />
number of accident-level and person-level covariates.<br />
The findings of these analyses are as follows:<br />
. In car-to-car crashes, the change in injury rate<br />
associated with the reduction in vehiclc flcet weight<br />
from 3,700 to 2,700 pounds has been cstimated from<br />
thc Texas data to be an additional 14 percent. The<br />
Maryland data produced an estimated incrcase in the<br />
serious driver injury rate of 4 percent for the shift<br />
from a 3,700 to a 2,700 pound averilge fleet weight.<br />
The impact on fatal injuries was not statisticfllly<br />
significant, possibly due to a paucity of state data<br />
for fatally injured drivers.<br />
. In collisions involving cars and medium/heavy<br />
trucks, thc change in the serious injury rate<br />
associated with the reduction in vehicle fleet weight<br />
from 3,700 to 2,700 pounds has been estimated frotn<br />
the Texas data to be an increase of approximately I I<br />
perccnt.<br />
. For single-vehicle nonrollovercrashes, the change in<br />
fatal injury rate associatcd with the rcduction in<br />
vehicle fleet weight from 3,700 to 2,700 pounds has<br />
been estimated from the Texas data to be an increase<br />
of approximately 10 percent.<br />
Background<br />
The objective of this effort wa$ to study the<br />
relationship between passenger car weight and safety.<br />
Two measures of safety were used for these analyscs: the<br />
rate of driver fatal or incapacitating injury (K+A) per<br />
driver involvcd, and the rate of fatal injury pcr drivcr<br />
involved (using the KABC injury coding scheme,<br />
94<br />
K = fatal injury, 1' = incapacitating injury, B = Dollincapacitating<br />
injury, and C = possible injury). In the<br />
rcmainder of this report the rate of fatal/incapacitating<br />
injury will bc rcfcrrcd to as the scrious injury rate, using<br />
"serious"<br />
in the general sense (rather than referring to<br />
the Abbreviated Injury Scale (AIS)). Driver injury rate<br />
was selected for the metric because information is<br />
routinely available for all drivers involved in crashes,<br />
while information for other car occupants (e.9.,<br />
right-front passengers) may be available only if the<br />
occupant was injured. The relationship between car<br />
weight and safety was studied accounting for the effects<br />
ofother background variables, such as driver age, posted<br />
speed limit, collision mode (left, right, rear, head-on),<br />
etc., in order to avoid their etfects confounding the<br />
conclusions regirrding car weight and safety.<br />
Thc National Highway Traffic Safety Administralion<br />
maintains a collection of state accident data files. Two<br />
states were used in this analysis: Maryland (l9lt4-88)<br />
and Texas (1984-87; data for 1988 were not yet avail*<br />
able). These accident data tapes were supplemented by<br />
data obtaincd from R. L. Polk and thc Fatal Accident<br />
Rcporting System on vchicle curb wcight.<br />
Methodotogy<br />
The dcpendent variable was defined as a dichotomous<br />
outcomc (0,1) indicating whether the specilic driver<br />
received a serious injury in the crash. The initial<br />
independcnt variables used included the weight of the<br />
driver's vehicle, the weight of the other vehicle in the<br />
crash, driver age, driver scx, safcly bclt use, and posted<br />
spccd limit or a surrogatc thcrcof. Thc data used for<br />
modcl estimation were always restricled to those cases<br />
for which the predictor variables all had known values.<br />
Since the dependent variable was dichotomous, the<br />
analytical method of choice was logistic regression. This<br />
methodology was selected because it presents the<br />
(conditional) probability of an outcome as a function of<br />
several independent variables, allowing the analyst to<br />
construct a modcl that adjusts for covariatc l'actors, whilc<br />
measuring thc cffcct of wcight.<br />
Through thc use of a logit transformation Ilogit(p) =<br />
ln(p/(l-p))1, the logistic regression model tp(x) =<br />
(exp(a+bx))/(l+exp(a+bx))l has many of the desirable<br />
properties of a linear regression model; that is, thc logit<br />
is linear in its parameters, it may be continuous, and may<br />
takc any value (rather than being confined to the range<br />
(0,1)).<br />
The Statistical Analysis System (SAS) was used to<br />
conduct the analysis; specifically, the program PROC<br />
LOGIST was employed. The LOGIST program is not<br />
part of the normally available SAS proccdurcs, but is<br />
supplied as a product of the SAS User Group set of
procedures. The output of PROC LOGIST includes,<br />
among other diagnostics, a table showing the estimate of<br />
the intercept and predictor variable coefficients, their<br />
standard errors, and measures of the variables' statistical<br />
significance. High values of a variable's chi-square<br />
statistic are associated with high statistical significance<br />
of the estimated predictor variablc coefficients. Variablcs<br />
are considered to bc statistically significant if P is less<br />
than a pre-selected value of alpha, often 0.0-5, as used in<br />
the current context.<br />
In the logistic regression model, the log odds ratio of<br />
thc outcome (that is, thc logit) is a linear combination of<br />
the indcpendent variables, i.e., the independent variable's<br />
coefficient represents the change in thc log odds ratio of<br />
the outcome (K+A injury) as a result of a unit change in<br />
the independent variable.<br />
For example, for dichotomous (0,1) predictor variables<br />
such as driver sex, the cocflicient represents how much<br />
more likcly (or unlikely) it is for a K+A injury to occur<br />
to males than for a K+A injury to occur to females, all<br />
other factors being held constant. On the other hand, for<br />
a continuous indcpcndent viuiable such as vehicle<br />
weight, the coelficient represents the chanBe in the log<br />
odds ratio frrr an increasc of one pound in wcight. To<br />
providc a useful interprctation for continuous scaled<br />
variables such as vehicle weight, discussion of the<br />
changes associated with this variable can be scaled to<br />
units of, for example, one hundred pounds. This is a<br />
simple lincar function of the initial coefficients<br />
appearing in the output tables.<br />
In determining an ovcrall approach to the modcling, it<br />
was decided initially to develop modcls for each<br />
individual crash mode; that is, cars with left-side<br />
damagc, cars with right-side damage, those with rcar-end<br />
damage, those with lrontal damage (the "striking"<br />
vehiclc in left-side, right-sidc, and rear-end collisions)<br />
and the head-on crashes (separately from the<br />
frontal-damaged vehicles due to the unique forces<br />
resulting from the head-on crash mode). This was done<br />
to accommodate the intuition that there should be<br />
differential likelihoods of K+A injury to drivers in the<br />
different modes. However, due to small sample sizes, or<br />
when indicated by model results (such as in the presence<br />
of homogencous estimated coefficicnts of weight ircross<br />
crash modes), all two-car crash cases were combined<br />
into a single larger analytical model, with the impact<br />
type accounted for by additional independent indicator<br />
and interaction variables.<br />
Analysis of Car-to-Car Crashes<br />
In this analysis, the data were restrictcd to cars<br />
(passenger cars, station wagons, and policc vehicles)<br />
involved in two-car crashes in which the first harmful<br />
event was a collision with ilnother passenger car, and for<br />
which curb weight could be dctermined either by use of<br />
the vehicle identification number (VIN) or makc/model<br />
code.<br />
Sectlon 3: Technlca/ SessJons<br />
Ilescription of the Injury Analyses by State<br />
7'exas<br />
The data were classified by crash mode using the<br />
variables VEH-DAM and VEH-MOV. VEH-DAM is<br />
coded according to the National Safety Council Vehicle<br />
Damage Scale and contains the location of the damage as<br />
well as the severity. VEH-MOV was used primarily to<br />
differentiate between head-ons and other striking<br />
vehicles with frontal impacts (strikcrs). CITY, indicating<br />
when RD-CLASS=-5, is used as an indication of spced,<br />
differentiating gcnerally between urbatr and rural roads,<br />
and thus, may also include sonrc effects of roadway<br />
gcometry. Each of these analyses addressed the<br />
following indepcndent variables:<br />
WEIGHT vehicle weight,<br />
OTHER-WT . . the wcight of the other vehicle<br />
involved in the crash,<br />
DR-AGE thc age of the drivcr.<br />
MALE an indicator variable for driver sex,<br />
VEH-ACE the age of the vehicle,<br />
BELTED an indicator variable for belt use.<br />
determined by RES_DEV,<br />
CITY<br />
an indicator variable for<br />
PCIMPCT ....<br />
RD_CLASS=S (this was used as a<br />
surrogirte for posted speed limit,<br />
since this is not coded on the Texas<br />
police accident report), and<br />
indicator variable for passenBer<br />
compartment impact determined by<br />
VEH_DAM (applicablc to right-and<br />
left-side impacts).<br />
The dependent variable was INJURY, defined by<br />
SEVERE = I or 4, indicating whether or not the driver<br />
sustained a serious injury. In addition, since the Texas<br />
file does not contain VIN, but contains a make/model<br />
code that could be merged with FARS to obtain vehicle<br />
weights, therc was no need to rcstrict the analysis to cars<br />
of model year l98l and later, ils was necessrry in<br />
Maryland. Thus, all model years were included for which<br />
weight could be obtained.<br />
A summary of the coefficients of WEIGIIT and<br />
OTHER_WT from these individual crash mode analyses<br />
is prcscntcd in Table l.<br />
Table 1. Welght Goefflclents ResultlnE from Inltlal tt/lodel<br />
Estimation (Texas)<br />
lmpact<br />
BETA for<br />
BETA for<br />
mods<br />
WEIGHT<br />
OTHER WT<br />
Head-on<br />
Striking<br />
Lsft<br />
Right<br />
Rear l<br />
-.00036236<br />
-.00050480<br />
-.00048ss8<br />
-.00052093<br />
-.0001 91 19 (-)<br />
(*) Not statistically significant at alpha=.05, (P=.1518)<br />
.00021315<br />
.00026335<br />
.00028987<br />
.00032001<br />
.00029249<br />
_-f,<br />
lt r<br />
!<br />
n<br />
:i,i<br />
::
13th lnternatlonal Technlcal Conterence on Experlmentat gafety Vehlcles<br />
Because of the close agreement between the<br />
coefficients of WEIGHT and OTHER_WT across crash<br />
modes (with the exception of WEIGHT for rear), a<br />
Iogistic regression was performcd on all the Texas data<br />
combining the various crash modes and rcpresenting<br />
them by indicator variables. The variablcs LEFT,<br />
RIGHT, I{EADONS and REAR were used, with<br />
STRIKING as the reference group.<br />
The coefficient of the belt use variable, BELTED, was<br />
highly statistically significant. Inspection of the<br />
dichotomous variable revcalcd an overall mean of over<br />
0.79, implying a 79 perccnt safety belt usage rate for<br />
drivers in crashes between the years 1984-1987. This<br />
rate appears to be higher than what one might expect,<br />
since observational surveys in the stflte indicate that<br />
before the mandatory safety belt usagc law became<br />
effective in September 1985, usage was l3 percent; aftcr<br />
the law was implementcd, usage varied between 54 and<br />
64 pcrcent, and usage among accident-involved drivers<br />
tends to be lower than that in the general driving<br />
population. Thus, a new model was estimated using the<br />
same variables as before with the exception of the<br />
BELTED variable. Since none of the coefficients of the<br />
other variables changed very much from the eiulier crash<br />
mode modcls, (except for a decrease in the intcrccpt),<br />
this last modcl was adopted for further use. The resulting<br />
estimated cocfficients, standard errors and chi-squarc<br />
values are displayed in Tablc ?.<br />
While WEIGHT and OTHER_WT are significant at a<br />
level ofalpha less than 0.0001, it can be seen from the<br />
CHI-SQUARE column that the two vehicle weight<br />
variables are not the most significant factors in<br />
detcrmining the probability of a serious injury, as<br />
compared to the variables HEADONS, CITY and<br />
PCIMPCT.<br />
To evaluate how well the model fits the data, the<br />
following procedure was employed: Thc prcdicted<br />
probability of serious driver injury was calculated for<br />
each drivcr using the BETA coefficients. On the basis of<br />
these prcdictcd probabilities, the data were organizcd<br />
into deciles of risk (probability of K+A injury): Group 1<br />
consists of the lowest tenth percentile,....Group 10 is the<br />
highest tenth percentile. In cach of these ten groups, lhc<br />
prcdicted and actual number of injuries werecomputcd.<br />
The rcsults are displayed in Table 3.<br />
Tablo 3. Actual vs. Predicted K+A lnluries for Decites of<br />
Fisk (Texas)<br />
Decile 2 3 4 5 6 7 8 9<br />
Actual<br />
Predicted<br />
Table 2. Hesults ol Final Model Estlmatlon Uslng WEIGHT and OTHER_WT (Texas)<br />
VAHIABLE BETA STD ERROR CHI.SOUARE<br />
INTERCEPT<br />
HEADON<br />
CITY<br />
PCIMPCT<br />
WEIGHT<br />
DH-AGE<br />
REAR<br />
MALE<br />
OTHER-WT<br />
LEFT<br />
RIGHT<br />
96<br />
-4.130997SS<br />
1.38896833<br />
-0.72298186<br />
0.989s8098<br />
-0.00043636<br />
0.01 1 762e4<br />
-0.85190000<br />
-0.31794031<br />
o.40024772<br />
0.26278595<br />
-0.2s230134<br />
0.1 7616148<br />
0.07080320<br />
0.05198303<br />
0.07394381<br />
0.00004225<br />
0.00153882<br />
0.12755110<br />
0.05087432<br />
0.00004014<br />
0.07394426<br />
0.08337704<br />
42 64 77 107 97 13S 147 183 215 s69<br />
s7 56 71 87 10s 128 1s7 200 276 ss3<br />
The goodness-of-fit of a particular model was assessed<br />
along the lines proposed by Hosmer and Lemeshow<br />
(Applied Logrslic Regresslon, John Witey & Sons, 1989),<br />
forming groups of observations based on the valucs of<br />
the estimated probabilitics of a driver K+A injury. The<br />
groups were formed based on dcciles (lOth percentiles),<br />
rcsulting in a test statistic with distribution closer to Lhc<br />
chi-squiue distribution with g-2 (the number of groups<br />
minus two) dcgrees of freedom, than is possible with<br />
groups based on fixed cutpoints. Thc tcn groups formed<br />
hased on thc deciles are often referred to as thc "deciles<br />
of risk," a tcrm borrowed from the health scicnces.<br />
The goodness-of-fit statistic is distributed approximately<br />
chi-square on eight degrees of freedom when the<br />
predicted probabilities are corect. Clearly, cach cell of<br />
the implied 2-by-10 tablc (thc rows are yes,/no-whethcr<br />
or not the driver received a K+A injury; the columns are<br />
thc dcciles) presented in Table 3 has sufficient cell size<br />
(greatcr than -5). The resulting stiltistic has a value of<br />
12.8811, less than thc critical value of 15.51 for alpha =<br />
0.05 with 8 dcgrces ol'freedom. Thus, the modcl l'its the<br />
data sufficiently well.<br />
It should be noted that unfortunately, there is no<br />
directly analogous test statistic to the linear regression<br />
R-squarcd, to describe the fit of the logistic regression<br />
model.<br />
54S.91<br />
384.84<br />
193.43<br />
17S.10<br />
106.66<br />
58.43<br />
44.61<br />
39.06<br />
38.0S<br />
12.63<br />
1?.?9<br />
0.0000<br />
0.0000<br />
0.0000<br />
0.0000<br />
0.0000<br />
0.0000<br />
0.0000<br />
0.0000<br />
o.0000<br />
0.0004<br />
0.0005
During model years 1970-1982, passenger cars became<br />
substantially smaller in the United States. The median<br />
curb weight ofcars decreased by about 1,000 pounds, the<br />
wheelbase by about ten inches, and the trackwidth by<br />
two or three inches. Since model year 1982, car weight<br />
has remained rather stnble. The weight reductions of the<br />
1970-1982 period were the result of a market shift from<br />
full-sized car$ to subcompact and imported cars, and,<br />
after 1975, downsizing within many domestic car lines.<br />
What would be the effect on the expected number of<br />
injuries as the average weight of the fleet changed from<br />
3,700 to 2,700 pounds?<br />
In order to estimate the effects of downsizing, an<br />
assumption was made regarding the means by which<br />
vehicle fleet weights changed. It was assumcd that the<br />
weight of cars would be reduced proportionally; that is,<br />
by a constant percenlagc rather than by a fixed amount.<br />
Thus, for example, two cars weighing 5,000 pounds and<br />
3,000 pounds would lose 500 and 300 pounds,<br />
respectively, under an assurnption of l0 percent downsizing.<br />
This seemed a more reasonable assumption compared<br />
to one which subtracted 400 pounds from each cat,<br />
but achieved the same overall weight reduction.<br />
Under this assumption, a last modcl was cstimated<br />
which permits one to focus on this assumed method of<br />
downsizing and produce estimated cflccts with an associated<br />
confidencc interval. This last model involves the use<br />
of the driver's vehicle's weight and the ratio of the<br />
vehicle's weight to the other vehicle's weight. Thcse two<br />
weight variables (WEIGHT and RATIO-WT) are<br />
mathematically equivalent to the information provided by<br />
the two individual vehicle weights (WEIGHT and<br />
OTHER_WT). The advantage of this approach is that by<br />
assuming proportional downsizing, only onc variable<br />
(WEIGHT) changcs in the hypothetical scenarios while<br />
the ratio of the two vehiclc wcights (RATIO-WT)<br />
remains constilnt before vs. after the downsizing,<br />
facilitating the computation of cstimated effects with<br />
their associated standard elTors.<br />
Thc results of estimating this model are presented in<br />
Table 4. As can be secn in Table 4. the coefficient of<br />
Table 4. Resulte of Flnel Modsl Eetimation Using WEIGHT and RATIO_WT (Texas)<br />
VARIABLE BETA STD EHROR CHI.SOUARE<br />
INTEHCEPT<br />
HEADON<br />
CITY<br />
PCIMPCT<br />
RATIO-WT<br />
REAR<br />
DR-AGE<br />
MALE<br />
RIGHT<br />
LEFT<br />
WEIGHT<br />
-9.10601898<br />
1.395?3779<br />
-0.725720?7<br />
0.98333735<br />
-1.01634198<br />
-0.77223'357<br />
0.00718748<br />
-0. 1 9367537<br />
-0.e8439361<br />
0.23720049<br />
-0.00013s49<br />
0.0578546S<br />
0.03186439<br />
0.02369631<br />
0.094s8127<br />
0,053120€0<br />
0.05796910<br />
0.00069573<br />
0,02279700<br />
0.03827928<br />
0.03387549<br />
0.00002426<br />
Sectlon 3: Tshnical Sesslons<br />
RATIO_WT is statistically significant, indicating a<br />
strong relationship between the ratio of the car weights<br />
in two-car crashes ancl the likelihood of driver $erious<br />
injury; that is, as the ratio of the weights of person A's<br />
car to person B's car increases, there is a decreased<br />
likelihood that person A will suflcr a serious injury. In<br />
this analysis, the coefficient of WEIGHT is statistically<br />
significant, indicating that, given the knowledge of the<br />
ratio of the two car weights, the absolute weight of<br />
person A's car is a significant factor in determining the<br />
likelihood of serious injury to person A in a two-car<br />
crash; the negative coefficient of WEIGHT indicates that<br />
as the wcight of person A's car decreascs, the driver's<br />
likelihood of scrious injury increases.<br />
The cocfficients in Table 4 werc used to estimate the<br />
effect on the expected number of injurics as the average<br />
weight of the fleet changed from 3,700 to 2,700 pounds,<br />
This was accomplished as follows. Recall that in the<br />
model, the logit(p) is a linear function of the independent<br />
variables, with thc estimates of the coefficicnts given in<br />
Table 4. If the values of the independent variables other<br />
than WEIGHT are held constant, the logit(p) becomes a<br />
linear function of WEIGHT. Selecting those valucs (not<br />
necessarily population averages) that makc wbar (the real<br />
average WEIGHT from thc dafa) correspond to pbar (tha<br />
real proportion of serious injurics froltt the data), results<br />
in thc function Q(WEIGHT) = logit(pbar) -0.00013549<br />
* (WEICHT-(wbar)). Q is a function of WEIGHT for<br />
which thc dcrivative is the coefficicnt of WEIGHT in<br />
Table 4 and such that Q(wbar)=logit(pbar).<br />
Applying Q at WEIGHT=2,700 (and 3,700) and<br />
computing thc antilogit results in the prcdicted probability<br />
of serious injury in itn othcrwise "typical"<br />
car/accident under the assumption of the average fleet<br />
weight of 2,700 (and 3,700) pounds. The two values are<br />
compared to conrpute the cstimated percentage change in<br />
the likelihood ot injury for a fleet avcrage of 2,700<br />
pounds vs. 3,700 pounds. Upper and lower confidcnce<br />
bounds are obtained by substituting bounds for the<br />
cocfficient of WEIGHT using the standard crror<br />
presented in Tablc 4.<br />
2882.2s<br />
1917.28<br />
945.71<br />
808.5<br />
66.06<br />
177.46<br />
106.73<br />
72.18<br />
55.20<br />
49.03<br />
31.19<br />
0.0000<br />
0.0000<br />
0.0000<br />
o.0000<br />
o.0000<br />
0.0000<br />
0.0000<br />
0.0000<br />
0.0000<br />
0.0000<br />
0.0000
lSth lnternatlonal Technlcal Conterence on Experlmentel Safety Vehlcles<br />
Assuming all other factors remain constant, a<br />
reduction in the averagc vehiclc weight from 3,700<br />
pounds to 2,700 pounds would result in an estimated<br />
increase of 14.3 percent in the number of driver K+A<br />
injuries. The 95 percent confidence interval ranges from<br />
an increase of 9.1 percent to an increase of 19.8 percent.<br />
It should be kept in mind that this effect represents the<br />
NET change accrued by both drivers in the crash; the<br />
actual changes that occurred individually for each driver<br />
associated with the changes for each car are larger in<br />
magnitude. That is, while onc driver would accrue a<br />
benefit if thc other driver's car were lighter, the other<br />
driver would experience a liability (increased likelihood<br />
of injury) larger than the first driver's benefit, resulting<br />
from the smaller weight of his car. The model predicts<br />
a net liability from the decrease in wcight of the car<br />
since the coefficient for WEIGHT is greater in magnitude<br />
(absolute value) and with opposite sign from the<br />
coefficient for OTHER-WT, as evidenced by the modcl<br />
results in Table 3 and the negative coefficient of<br />
WEIGHT in Table 4.<br />
Maryland<br />
Vehiclcs were categorized into crash modes using the<br />
variables point of impact (PT_IMPCT) anrl collision typc<br />
(COL_TYPE) to distinguish the rolc of the car in the<br />
crash as head-on (both cars with frontal tlamage),<br />
striking (frontal damage in othcr than a head-on crash),<br />
left-side damaged, right-side damaged or rear-end<br />
damaged. PT-IMPCT is a vehiclc-level variable that<br />
indicates what part of the car's body was contacted;<br />
COL_TYPE is an accident-level variable that dcscribes<br />
the type of crash; specifically, it generically identifies<br />
the pre-crash paths of the two vehicles that collidcd.<br />
COL*TYPE was used in thc two-car analysis to identify<br />
two-car crashes, eliminate sideswipes, and differentiate<br />
head-on crashes from other crashes in which the front<br />
portion of one vehicle hit another vehicle (referred to<br />
hereinafter as "striking" vehicles). The first analyscs<br />
considered these five crash modes individually.<br />
In each of the individual crash mode models. the<br />
independent variables employed as candidates wcre:<br />
98<br />
WEIGHT vehicle weight,<br />
OTHER-WT . . the weight of the other vehicle<br />
involved in the crash,<br />
DR-AGE the age of the driver,<br />
MALE an indicator variable f'or driver sex.<br />
VEH*AGE the age of the vehicle in years,<br />
TWO_DR.... an indicator variable for two-door<br />
vehicles determined by the<br />
WET .<br />
VlN-derived body type (VINA_BD)<br />
an indicator variable for wet road<br />
surface,<br />
BELTED an indicator variable for belt use<br />
detcrmincd by DR_SAFE,<br />
SPD_LIM . . .. speed limit on a scale of 2 to 8 (2<br />
corresponds to up to 25 mph,..,8<br />
conesponds to 55 mph), and<br />
PCIMPCT . . . . an indicator variable denoting a<br />
passenger compartmeni impact (i.e.,<br />
between the axles) determined by<br />
PT-IMPCT.<br />
The dependent variable was INJURY, an indicator<br />
variable for a driver serious injury (K+A) determined by<br />
the variable DR_INJ = 4 or 5. It is the abscnce or<br />
presence of such a K+A injury for each driver,<br />
associated with that driver's particular set of driver,<br />
vehicle, and environmental factors, that forms the basis<br />
for estimating the cffect of these factors on the<br />
probability of driver injury.<br />
In all of the initial five crash mode models, the<br />
coefficients of TWO-DR, VEH*AGE and WET were<br />
never statistically significant and were dropped from<br />
further analysis. In each of the five crash modes, the<br />
coefficient of WEIGHT was negative (denoting an<br />
inverse relationship between the driver's vehicle's<br />
weight and injury probability), and the coefficient of<br />
OTHER_WT was positive (denoting a direct relationship<br />
bctwccn drivcr injury rate and the weight of the other<br />
vehicle in the crash).<br />
ln these five crash mode analyses, the levels of<br />
statistical significance for the variablcs WEIGHT and<br />
OTHER-WT appeared to be relatcd to the sample sizes.<br />
For example, there wcrc ovcr I I,000 vehiclcs in the<br />
striking category (624 drivers of which received a K+A<br />
injury) and in this group all variables in the model that<br />
were significant at level alpha = 0.05 were also<br />
significant at alpha = 0.01. In the head-on category, with<br />
about 1,700 vehicles and 254 K+A driver injuries,<br />
WEIGHT was not significant and OTHER_WT was<br />
significant at lcvcl alpha = 0.0-5 but not at alpha = 0.01.<br />
A summary of thc samples sizes by crash mode is<br />
displaycd at Tablc 5.<br />
Table 5. Sample Sizes lor Various Crash Modes<br />
(Maryland)<br />
Grash K+A<br />
Mode Injury<br />
HEADON<br />
STRIKING<br />
LEFT<br />
RIGHT<br />
REAR<br />
254<br />
624<br />
436<br />
306<br />
289<br />
No<br />
Injury Total P(K+A)<br />
1.4ss<br />
10,431<br />
5,941<br />
5,343<br />
4,855<br />
1,70S<br />
1 1,055<br />
6,377<br />
5,64S<br />
5,1 44<br />
0.149<br />
0.056<br />
0.068<br />
0 054<br />
0.056<br />
To make use of a larger database, all crash modes<br />
were combined with STRIKING as the baseline, or<br />
reference group, and HEADON, LEFT, RIGHT and<br />
REAR as indicator variables (the five nominal lcvcls of<br />
the crash mode can be represented by four dichotomous
variables). In this analysis, the modes HEADON and<br />
LEFT were statistically significant, while REAR and<br />
RIGHT were not, matching the similarity of the ovcrall<br />
probabilities of K+A injury calculated in the rightmost<br />
column of Table 5.<br />
Another analysis was performed using all the<br />
Maryland data with indicator variables only for the<br />
modes I{EADON and LEFT, significtnt from th$<br />
previous model estimation. In this analysis, interaction<br />
terms mode'r'WEIGHT and mode*OTHER_WT were<br />
included for the significant modes (HEADON and<br />
LEFI). Passengcr compartment impact {PCIMPCT) and<br />
its interaction with WEIGHT and OTHER_WT were also<br />
included in this second cornbincd Maryland analysis.<br />
None of the interaction terms were sigrrificant at the<br />
level 0.05; thus, the interaction terms were dropped from<br />
subsequcnt consideration.<br />
A subsequent logistic regression model was estimated<br />
using the following independent variables: WEIGHT,<br />
OTHER-WT. PCIMPCT, SPD_ LIM, DR-ACE, MALE,<br />
BELTED, RIGHT. REAR, LEFT and HEADON. The<br />
variables that were significant were WEIGHT,<br />
OTHER-WT, I{EADON, SPD_LIM. MALE, PCIMPCT,<br />
BELTED and RIGHT. This model appeilr$ to produce a<br />
reasonable fit. The coefficient of the belt use variable.<br />
BELTED, wrrs highly stfltistically significant. Howcver,<br />
inspection of the dichotomous variable revealcd an<br />
overall mean of over 0.76, implying a 76 percent safety<br />
belt usage rate for drivers in crashes during the years<br />
1984-1988. This ratc appears to behighcr than what one<br />
might expcct, since observational surveys in the state<br />
indicate that before the mandatory safcty belt usage law<br />
became effective in July 1986, usage in the general<br />
driving population was 28 percent; after the law was<br />
implemented, usage varied between 60 and 74 percent,<br />
and usage among accident-involved drivers tends to be<br />
lower than that in the general driving population. Thus,<br />
a new model was estimated using the same variables as<br />
bcforc with the exception of the BELTED variable. Since<br />
the omission of BELTED resulted in very littlc change<br />
in any of the other coefficients except for a decrease in<br />
the intercept (a constant term relating to the overall<br />
injury likelihood), and because this model also produced<br />
Tabb 6. Heeults of Flnal Model Estimetion Urlng WEIGHT and OTHER*WT (Maryland)<br />
VARIABLE STD ERROH CHI.SOUABE<br />
INTERCEPT<br />
HEADON<br />
SPD-LIM<br />
MALE<br />
PCIMPCT<br />
WEIGHT<br />
OTHEH-WT<br />
RIGHT<br />
.3.15868444<br />
1.1 961 7502<br />
0.1 8845292<br />
-0.69666459<br />
0.7122n58<br />
-0.00027215<br />
0.00019035<br />
-0.02609507<br />
o.1715€,814<br />
0.o7569392<br />
0.01232934<br />
0.0494S274<br />
0.o740?425<br />
0.00004469<br />
0.000041 15<br />
0.00697340<br />
$ectlon 3: Technlcal $essions<br />
a reasonable fit, this last model was adopted for further<br />
use. The rcsults are displayed in Table 6.<br />
While WEIGHT and OTHER*WT are significant at a<br />
level alpha less than 0.0001, it can be seen from the<br />
CHI-SQUARE column that vehicle weights arc not the<br />
most significant factors in determining the probability of<br />
a serious injury as compared to HEADON, SPD_LIM,<br />
and MALE.<br />
The chi-square diagnostic statistic indicates that the<br />
model fits the data sufficiently well. lt should also be<br />
remembered that ncither weight nor thc othcr car's<br />
weight was the most statistically signilicant predictor<br />
variable in the model. and that lhe fit of the model is a<br />
reflection of ALL of the variables employed therein.<br />
From Table 6, thc cstimflted coefficient for WEIGHT<br />
is negative and for OTHER_WT, the estimatcd coefficient<br />
is positive. This indicates that the likelihood of a<br />
serious driver injury in a two-car crash decreases with<br />
increasing vehicle weight, but increases with the<br />
increasing weight of the other vchicle. However, the<br />
harm of decreasing the weight of one's own vehicle is<br />
less than offset by the hencfit of dccreasing the weight<br />
of the othcr vehicle, as evidenced by thc coefficients of<br />
WEIGHT and OTHER WT.<br />
In order to estimflte the effects of downsizing, a last<br />
model wa$ estimated which permits one to focus on this<br />
assumed method of downsizing and produce estimated<br />
effects with an associated confidcnce interval. This last<br />
modcl involves the use of the driver's vehicle's wcight<br />
and the ratio of the vehicle's weight to the other<br />
vehicle's weight, as was done in the Tcxas rrnalysis. The<br />
results of estimating this model are presented in Table 7.<br />
As can be seen in Tablc 7, the coefficient of<br />
RATIO_WT is statistically significlnt, indicating a<br />
strong relationship Lretween thc ratio of the ciu weights<br />
in two-car crashes and the likelihood of driver serious<br />
injury: that is, as the ratio of the wcights of person A's<br />
cflr to person B's car increase.s, there is a decreased<br />
likelihood that person A will suffer a scrious injury. In<br />
sirnplcr terms, in car-to-car crashes, the driver of the<br />
lightcr car faces a significantly greater risk of serious<br />
injury than does the driver of thc hcavier car. However,<br />
the cocfficient of WEIGHT is not stotistically significant,<br />
338.95<br />
249.73<br />
233.63<br />
I 98.1 4<br />
92.59<br />
37.08<br />
21.40<br />
13.00<br />
0.0000<br />
0.0000<br />
0 0000<br />
0.0000<br />
0.0000<br />
0.0000<br />
0.0000<br />
0.0002<br />
.a
13th tntematlonal Technlcal Gonference on Experlmental Safety Vehlcles<br />
Table 7. He3ults of Flnal Model Estimatlon UelnE WEIGHT and RATIO-WT (llteryland)<br />
VARIABLE BETA STD ERFOR CHI.SOUARE<br />
INTERCEPT<br />
HEADON<br />
SPD-LIM<br />
MALE<br />
PCIMPCT<br />
RATIO-WT<br />
RIGHT<br />
WEIGHT<br />
2.64515627<br />
1.27161193<br />
0.19696302<br />
-0.69616218<br />
0.71971 128<br />
-0.60'1669€6<br />
-o.2512284€<br />
-o.000045@<br />
0.126s3093<br />
0.071 75126<br />
0.01188887<br />
0.04767112<br />
0.07143688<br />
0.1 1096896<br />
0.06739234<br />
0.00005984<br />
indicating that, given the knowledge of the ratio of the<br />
two car weights, the absolute weight of person A's car<br />
is not a significant factor in determining the likelihood<br />
of serious injury to person A in a two-car crash.<br />
The coefficients in Tabte 7 werc used to estimatc the<br />
effect on the expected number of injuries as the avcrage<br />
weight of the fleet changed from 3,700 to 2,?00 pounds'<br />
This was accomplished as was done for thc Texas<br />
analysis.<br />
Applying Q at WEIGHT=2,700 (and 3.700) and<br />
computing the antilogit results in the predicted<br />
probability of serious injury in an otherwise "typical"<br />
car/accident under the assumption of the avcrage fleet<br />
weight of 2,700 (and 3,700) pounds. Thc two values are<br />
compared to compute the estimated percentage change in<br />
the likelihood of injury for a flect average of 2,700<br />
pounds vs. 3,700 pounds. Uppcr and lower confidence<br />
bounds are obtained by substituting bounds for the<br />
coefficient of WEIGHT using the standard error<br />
presented in Table 7.<br />
Assuming all other factors remain constant, a<br />
reduction in the flverage vehicle wcight from 3,700<br />
pounds to 2,?00 pounds would result in an estimfttcd<br />
increase of 4.3 percent in the number of driver I(+A<br />
injuries. The 95 percent confidencc interval ranges from<br />
a decrease of 6.5 percent to an incrcase of 16.5 percent'<br />
Description of Fatality Analysis<br />
The analysis of the effect of car weight on fatality risk<br />
was conducted in the same manner as the previous<br />
analyses of injury risk. The numbcr of fatalities that<br />
occurred in the Stflte of Maryland during the period<br />
1984-1988 in two-car crashes was too small for meaningful<br />
analysis. However, data for the State of Texas during<br />
the period 1984-1987 provided a sufliciently largc<br />
sample size to attempt to estimate thc rcgression modcl,<br />
with the proviso that crashes involving pre-198I model<br />
year cars could be included in thc analysis. This<br />
protluced a dataset of 638,178 driver obscrvations of<br />
which 533 were fatally injured.<br />
In this analysis the coefficient of WEIGHT was not<br />
statistically significant. The small number of fatal<br />
injurics in this dfltasct (533 out of 638,178 involvcd<br />
drivers) likely precludes one from drawing any lirm<br />
100<br />
437.03<br />
314 0e<br />
274.47<br />
213.26<br />
101.50<br />
a9.69<br />
I3.1S<br />
o.57<br />
0.0000<br />
0.0000<br />
0.0000<br />
0.0000<br />
0.0000<br />
0.0000<br />
o.o0pz<br />
0.4512<br />
inferences on the effect of vehicle downsizing on fatal<br />
injury risk.<br />
Anatysis of Car-Medium/Heflvy Truak<br />
Crashes<br />
Only the State of Texas provided sufficient numbers<br />
of car-medium/heavy truck (gross vehicle weight rating<br />
(GVWR) grcater than 10,000 pounds) crashes for<br />
analysis. As the Texas data did not contain the vehicle<br />
identification numbcr (VlN) FARS data were used to<br />
estimate passenger car weights. Thc FARS weight is the<br />
avcrage weight reported in FARS 1984 through 1989, for<br />
passengcr cars of the same make, model and model year.<br />
The Texas logistic regression addressed the following<br />
independent variables:<br />
WEIGHT . . .. FARS weight,<br />
DR-AGE . . . . the age o[ the driver,<br />
DR*SEX . . . . an indicator variable for driver sex,<br />
HEAD-ON . . . iln indicator variablc for head-on<br />
impact, and<br />
LEFT . and indicator variable for left-side<br />
impact.<br />
The dependent variable was INJURY, defined by<br />
SEVERE = I or 4, indicating whether or not the<br />
pas$enger car driver sustained a fatal or incapacitating<br />
injury. The analysis included 19,256 passenget car<br />
drivers involvcd, of which 898 received serious injury.<br />
Thcrc are several rcasons why the truck wcight and<br />
the truck driver's injury were not incorporated into lhc<br />
model. First, thc weight of thc truck is not rcadily<br />
available sincc trucks generally are classified by their<br />
gross vehicle wcight rating. Second, whether or not the<br />
vehicle was carrying cargo at the time of thc crash is not<br />
always available on thc accident files; thc presence of<br />
cargo can significantly alter the weight characteristics of<br />
thc truck. Third" thc sheer size of the truck is likely to be<br />
equivalent to a passcnger car colliding with a fixed<br />
objcct such as a barricr. The absence ol the truck driver<br />
injury in the model is based upon the premise that the<br />
truck driver's injury likelihood is not very sensitivc to<br />
changes in thc weight of the passenger car, especially if<br />
the car collides with the trailer, which can be far<br />
removed from the truck cab.
The resulting e$timated coefficients, standard errors<br />
and chi-square values are displayed in Table 8.<br />
Note that while the coefficient of vehicle weight is<br />
statistically significant at the 0.05 level, it is not the<br />
mo$t significant factor in predicting the likelihood of<br />
incapacitating injury.<br />
What would be the effect on the expected number of<br />
injuries as the average weight of the fleet chiurged from<br />
3,700 to 2,700 pounds? The coefficients in Table 8 were<br />
used to estimate the effect on the expected number of<br />
injuries as the average weight of the fleet changed from<br />
3,700 to 2,700 pounds. This was accomplished in the<br />
same manner as previously.<br />
Assuming all other fActors remain constant, a<br />
reduction in the average vehicle weight from 3,700<br />
pounds to 2,700 pounds would result in an estimated<br />
increase of I1.0 percent in the number of driver serious<br />
injuries in crashes betwecn a car and a medium/heavy<br />
truck. The 95 percent confidence interval rllnges from an<br />
increase of 0.5 percent to itn increase of 22.'l percent.<br />
Analysis of Fatal Single-Vehicle<br />
Nonrollover Crashes<br />
Only the State of Texas provided sufficicnt numbers<br />
of fatal single-vehicle nonrollover crashes for analysis.<br />
As the Texas data did not contain the vehicle idcntification<br />
number (VIN) FARS data were used to estimilte<br />
vehicle weights. The FARS weight is the average weight<br />
reported in FARS 1984 through 1989, for vehicles of the<br />
same make, model and model year. The Texas logistic<br />
regression addrcssed thc following indepcndent<br />
variables:<br />
WEIGHT FARS weight,<br />
DR_AGE the age of the driver,<br />
Table 8. Fesults of Model Estlmation (Texas)<br />
DR-SEX<br />
TWO-DR<br />
WET RD<br />
SPEED<br />
VAHIABLE BETA STD EHROH CHI-SOUARE<br />
INTERCEPT<br />
HEAD-ON<br />
DR-AGE<br />
WEIGHT<br />
-3.02.42223a<br />
1.67401291<br />
0.00519428<br />
-0.00010937<br />
Tabb 9. Re*ults of Modal Estimetion<br />
llexae)<br />
0,1 6760401<br />
0.1 01 46955<br />
0.0020€M0<br />
0.00005339<br />
$ec'tlon 3: Technlcal Sesslons<br />
an indicator variable for driver sex,<br />
an indicator variable for two-door<br />
vehicles<br />
an indicator variable for wet road<br />
surface,<br />
an indicator variable for a 55 mph<br />
road.<br />
FRONT...... an indicator variable for front<br />
impilct, and<br />
DAMAGE an interval scaled variable<br />
representing TAD, a descriPtion of<br />
thc damagc to the vehicle (0 to 7).<br />
The dependent variable was FATAL, defined by<br />
SEVERE - 4, indicating whether or nol the driver<br />
sustained a fatal injury. The analysis included 112,486<br />
drivers involved, of which I,I19-were fatally injured.<br />
The resulting estimated coefficients, standard errors<br />
and chi-square values are displaycd in Tablc 9.<br />
Note that while vchiclc weight is ttot the most<br />
significant factor in predicting the Iikclihood of<br />
incapacitating injury, the coefficient is slittistically<br />
significant at a level of alpha lcss than 0.05.<br />
What would be the ell'ect olt the expected number of<br />
injuries as the averagc wcight of thc flcet changcd from<br />
3.700 to 2,700 pounds'l This was computed as in the<br />
samc nlflnncr as was done previously.<br />
Assuming all other factors remain constf,nt, a<br />
reduction in the average vehicle weight from 3,700<br />
pounds to 2,700 pounds would result in an eslimated<br />
increase of 9.8 pcrccnt in the nutrtbcr of drivcr latal<br />
injuries in single-vehicle nonrollover crashes. The 95<br />
percent confidence interval ranges from an increase of<br />
0.-5 pcrccnt to an increasc ol 19.9 percent.<br />
325.58<br />
27?.17<br />
6.32<br />
4.20<br />
VARIABLE BETA STD ERHOR CHI.SOUARE<br />
INTERCEPT<br />
DA['AGE<br />
DR-AGE<br />
DR-SEX<br />
WEIGHT<br />
-s.4s777721<br />
0.93292219<br />
0.02981796<br />
0.38937032<br />
- 0.00009420<br />
0.1 9388549<br />
0.02039251<br />
0.00202257<br />
0.07537S 14<br />
0.00004563<br />
239S.68<br />
e09?.e0<br />
217.U<br />
26.68<br />
4.26<br />
0.0000<br />
0.0000<br />
0.0119<br />
0.0405<br />
0.0000<br />
0.0000<br />
0.0000<br />
0.0000<br />
0.0390
lSth lntemetlonal Technlcal Conbrence on Expeilmantal Setety Vehlcles<br />
Discussion<br />
As a result of the analyses reported herein, there is<br />
evidence that drivers of downsized vehicles have a<br />
higher risk of injury in crashes involving pas$enger cars<br />
than would have been the case had the 1,000 pound<br />
downsizing not occurred. However, the evidence does<br />
not show a significant association of vehicle weight with<br />
fatality risk in two-car crashes.<br />
The means o[ demonstrating this has been to use the<br />
models developed for the Maryland and Texas accident<br />
data to estimate the number of K+A injuries and fatal<br />
injuries that would have occurred had the twcl siate car<br />
fleets averaged 3,700 pounds vs. 2,?00 pounds. This<br />
change in car weight is the estimated effect of the weight<br />
reduction that occurred during the 1970-1982 time<br />
period.<br />
The effects of changes in passenger car weight<br />
reported herein represent changes as thc vehicles were<br />
used in contrast to as the vehicles were enginccrcd. That<br />
is, for example, cars of differcnl weights may be driven<br />
more or less aggressivcly. If lhere were a tendency for<br />
smaller cars to be driven by younger drivcrs, and if they<br />
in turn tended to drive their cars more aggressively than<br />
did older drivers. this would lead to accidents with<br />
greater pre-crash or closing speeds, compared to<br />
accidents involving larger cars drivcn by older drivers.<br />
While the Maryland analysis incorporated posted speed<br />
limit in the analysis, this may not be sufficient to<br />
account for thc potential clifferences in pre-crash travcl<br />
speeds within the categorics of posted speed limit. While<br />
differential closing speeds would not be an issue in<br />
accidents involving a larger and a smaller car, under this<br />
hypothesized scenario, accidents involving two small<br />
cars may involve higher pre-crash travel spceds than do<br />
accidents involving two large cars, accounting for some<br />
of the higher predicted K+A injury rate. However, the<br />
stflte data files used in these analyses did not report<br />
pre-crash travel speeds. In spite of this, the analyses and<br />
effccts rcported herein are valid represcntations of the<br />
et'fects of car weight as thcsc cars were used.<br />
Changes in Two-Car Crashes<br />
The change in injury rate associnted with the reduction<br />
in vehiclc flect weight from 3,700 to 2,700 pounds has<br />
been estimated from the Texas data to be an additional<br />
14.3 percent serious injuries to drivcrs. Thc Maryland<br />
data produced an estimated increase in K+A driver<br />
injuries of 4.3 percent for thc shift from a 3,700 to a<br />
2,700 pound aYcragc flcct weight.<br />
The NASS General Estimalcs System for l9ll9 reports<br />
that the number of passenger car drivcr K+A injuries in<br />
two-car crashes was 85,768 (total occupant K+A injuries<br />
in these crashes numbered 128,974).<br />
Gencralizing thc rcsults to all occupants of passenger<br />
cars and applying the estimated effects derived in the<br />
analysis leads to estimated national annual net increases<br />
of 16,156 K+A injuries based on the Texas analysis, and<br />
102<br />
5,329 K+A injuries based on the Marylflnd analysis,<br />
associated with the 1,000 pound shift in vehicle weight.<br />
Under the assumption that thc effects noted for drivers<br />
could be generalized to all passengcr car occupants, one<br />
can estimate the changes in total occupiut injury<br />
associated with the 1,000 pound shift. All of these<br />
estimates and their associated 95 percent confidence<br />
intervals are presentcd in Table 10.<br />
Table t0. Estimated NationalAnnualChanges in Iniuries<br />
to Occupants of Passenger Care in Two-Gar Creshes<br />
Associated with the Shift in Fleet Average Weight from<br />
3,700 to 2,700 Pounds<br />
Catrgory<br />
Drivers<br />
K+A Iniurieq<br />
Texas<br />
Maryland<br />
All Occupants<br />
KtA Lniunes<br />
Texas<br />
Maryland<br />
95V" Lower 95% Upper<br />
<strong>Conf</strong>idence <strong>Conf</strong>idencg<br />
Estimab Bound Bound<br />
10,744<br />
3,544<br />
1 6,1 56<br />
5,SeS<br />
7,132<br />
- 5,972<br />
10,725<br />
- 8,981<br />
14,187<br />
1 2,141<br />
21,334<br />
18.257<br />
The estimates presentcd reprcsent the NET eftect of<br />
the 1,000 pound decrease in curb weight, which,<br />
generally speaking, are the sum of the benefits and<br />
liabilities accruing to each drivcr in turn. Howevcr, since<br />
smallcr cars cxpcrience higher injury rates in two-car<br />
crashes, there is a net liability that results frorn the<br />
weight reduction of all cars in the fleet.<br />
Changes in Car-MediumlIIeavy Truck Crashes<br />
The change in fatal and incapacitating injury rate<br />
associated with thc reduction in vehicle fleet weight<br />
from 3,700 to 2,700 pounds has been estimated from the<br />
Tcxas data to be an estimated increase in fatal driver<br />
injurics of ll.3 percent fbr the shift from a 3,700 to a<br />
2,700 pound averagc flcct wcight<br />
Thc NASS General Estimates System for 1989 reports<br />
thflt the numher of passenger citr driver serious (K+A)<br />
injuries in crashes involving a car and a medium/hcavy<br />
truck was 12,139 (total occupant serious injuries in these<br />
crashcs numbered 17,858). Applying the estimated effect<br />
derived in the analysis and generalizing the results to all<br />
passcnger car occupants lcads to estimated national<br />
annual net increases of 1,770 serious injuries associated<br />
with the 1,000 pound shitt in vehiclc wcight. The 95<br />
percent lower and uppcr confidence bounds are an<br />
increase of 80 serious injuries and an incrcasc of 3,303<br />
serious injuries.<br />
C hanges in Single-Vehicle Nonrollover Crashes<br />
As a result of the analysis reportcd herein, there is<br />
evidcncc that drivers of smaller cars have a higher risk<br />
of tatal injury in single vehicle non-rollover crashes than<br />
do drivcrs of larser cars.
The means of demonstrating this has been to use the<br />
model developed for the Texas accident data to estimate<br />
the number of fatal injuries that would have occuned<br />
had the two state car fleets averaged 3,700 pounds vs.<br />
2,?00 pounds. This change in car weight is the estimated<br />
effect of the weight reduction that occurred during the<br />
1970-1982 time pcriod.<br />
The change in fatal injury rate associated with the<br />
reduction in vehicle fleet wcight from 3,700 to ?,700<br />
pounds has been estimated from the Texas data to be an<br />
estimated increase in fatal driver injuries of 9.8 percent<br />
for the shift from a 3,700 to a 2,700 pound average lleet<br />
weight.<br />
Data from the Fatal Accident Reporting System for<br />
1989 shows that there were 4,880 fatally injured drivers<br />
in single-vehicle nonrollover crashes, and a total of<br />
7,108 ffltally injured occupants (including drivers) in<br />
such crashes. Applying the estimated effects derived in<br />
the analysis leads to estimated annual net increases of<br />
435 driver fatalities and 633 total occupant tatalities<br />
based on the analysis of Texas accident drta, associated<br />
with the 1,000 pound shift in vehicle weight. The 95<br />
percent lower and upper confidence bounds lor these<br />
estimates are: 23 and 8ll for driver fatillitics; 33 and<br />
1,182 for total occupant fatalities.<br />
Concluding Remarks<br />
The estimated effects reported herein are based on<br />
historical relationships between car weight and injury<br />
riltes as evidenced by the crash experience of all cars for<br />
the 1984-1987 Texas accident data and l98l and later<br />
model year cars during the 1984- 1988 Maryland accidcnt<br />
data time frames.<br />
Differences between the crashworthiness levels of the<br />
fleet of the 1970's compared with that of the 1980's<br />
could not be addressed in the current analysis of<br />
Maryland data, since only vchicles of model ycars l98l<br />
st.o.t2<br />
Compatibility Problems of Small and<br />
in Head on Collisions<br />
G. Ernst; Dr. Briihning, E;<br />
Glaeser, K.P.; Schmid, M.<br />
Federal Highway Research Institute, BASt<br />
<strong>Int</strong>roduction<br />
Road accidents may involve collisions between<br />
vchiclcs of diflcrent weights undcr a varicty of<br />
circumstances. It is rare for vehicles of equal weight to<br />
collide. The range of vehicle curb weights (masses)<br />
extends from less than 700 kg (e.g. VW Polo) to over<br />
2,000 kg (c.g. Daimler Benz., S-class). In accordance<br />
with the impact laws of mechanics, the consequences of<br />
collision involving smaller and larger vehicles are mostly<br />
<strong>Section</strong> 3: Technlca/ Sessions<br />
and later were included in the Maryland accident dilta<br />
analysis. These statistical models and results do not<br />
account for changes in the number of crash involvemcnts<br />
that might occur undcr thc assumptions of downsizing,<br />
but do represcnt the real-world experience as manifested<br />
in the States of Maryland and Texas. To the extent that<br />
car weight reduction affects the relative likelihood of<br />
crash involvement, the models and estimatcd effccts do<br />
not take this into account, leaving the projected<br />
involvement of cars by weight in the same rclative<br />
proportions as that which occurred in the accident dtta.<br />
Analyses of different states would probably produce<br />
somcwhat diffcrent results. Differences in the results<br />
between the Maryland and Texas analyscs could be<br />
attributable in part to normal variation; differences in<br />
reporting threshold of accidcnts; di[[crences in the<br />
coding of injuries (e.g., an injury may be called<br />
incapacitating in one state and non-incapacitating in<br />
another); differenccs in thc availability of known driver,<br />
vehicle and accident data (in this study, only complctc<br />
cases were used; that is, whcrc all variables had known<br />
attributcs); and other factor$ that might affect the<br />
reporting and coding of accident characteristics.<br />
With regard to reporting threshold, the State of<br />
Maryland has a threshold of $100, a fatality or pcrsonal<br />
injury; the State of Texas has a threshold of $250, a<br />
filtality or personal injury. However, the reality of<br />
reporting threshold may be substantially dil'l'crcnt than<br />
that which has been reported by states to NHTSA in the<br />
past. Differences in reporting threshold affcct the overall<br />
probability of injury as well as thc mix of accidents<br />
reported by a state. Since data are not collectcd in any<br />
uniform or consistent manncr from one state to another,<br />
it is difficult to rcconcilc obscrvcd differences. Thus, the<br />
reported effects arc presented separately for each state<br />
rather than as a range, or as an avcrage effect.<br />
Large Passenger Cars<br />
more serious for the driver and passengers of the smaller<br />
vehicle. In the past, it hfls not always bccn possible to<br />
conrpletcly quantify the scriousncss of accidents or the<br />
risk of being injured or killed in Germany because thcre<br />
is no direct link between vehicle mass and the seriousness<br />
of passenger injuries. All that is availablc at present<br />
is a study by an insurance association [-5] bascd on single<br />
accident cases. This analysis covered fronl-scat<br />
passengers using scat belts as well, but not only the<br />
drivers.<br />
An American study [7J estimate the risk of bcing<br />
killcd in an accident in a small car (subcompact) very<br />
generally as being 8 times higher than the risk in a larger<br />
vehiclc (fullsize car). Exatnitting cars of different milsses<br />
103<br />
itl<br />
.<br />
,:J<br />
.:l<br />
:l<br />
-;
13th lnternatlonal Techntcal <strong>Conf</strong>erence on Experlmental Satety Vehicles<br />
and of equal masses involved in accidents (comparison<br />
between vehicles weighing 900 kg and vehicles weighing<br />
1,600 kg), in [4], on the basis of the FARS (Fatal<br />
Accident Reporting System), note a ratio of 2:1 for the<br />
risk of being fatally injured in a small car as against the<br />
risk of being fatally injured in a larger vehicle. However,<br />
the results of US studies cannot always be translated to<br />
European conditions, since America's car population is<br />
quite different from the European on account of the large<br />
number of extremely large vehicles on US roads.<br />
A Swedish study by FOLKSAM lnsurance-which<br />
also included single-car accidents-found that drivers of<br />
800 kg vehicles have an injury frequency twice as high<br />
as that of 1,400 kg vehicles [61.<br />
Following an evaluation of the accident data for<br />
North-RhineAVestphalia now available for research<br />
purposes and extended to include automotive features, it<br />
is now possible to obtain results for the --compatibility"<br />
problcm in Gcrmany and in thc car population involvcd<br />
in accidents here. First results were published in [8]. The<br />
study is concerned with the seriousness of injuries<br />
focused to car drivers involved in accidents with oncoming<br />
traffic.<br />
Physical and Automotive Aspects of the<br />
('Compatibility"<br />
Problem<br />
The seriousness of accidents can be described using<br />
the impact laws of mechanics; one measure is the<br />
"change<br />
of velocity" in the accident.<br />
In the standard impact test against a rigid barrier, the<br />
deformation behaviour of the vehicle front is examined,<br />
and the protection afforded against serious injuries<br />
measured.<br />
Still, although impact ngainst the rigid barrier is a well<br />
estahlished testing procedure, it does constitute a special<br />
case in the real accident world. Where a vehicle drives<br />
into a rigid banier at e.g. 50 km/h, kinctic cncrgy is<br />
transformed to deformation of the vehicle front. The<br />
vehicle undergoes a 50 km/h change of velocity.<br />
To ensure optimal transformation of impact energy<br />
into work of deformation, the stiffness of thc front is<br />
designed in such a way that, to meet the sflfety st$ndard<br />
FMVSS 208, which providcs lor an impact at 30 mph<br />
(48 km/h) against a rigid barricr, advantage is takcn of<br />
the max. deformation path of approx. 50 to 60 cm of the<br />
vehicle front. and also that the survival area in the<br />
vehicle cell is not destroycd. Thc vchiclc structure, i.e.<br />
primarily the stiffness of the front side member, is<br />
optimated to this standard. This keeps the mean deceleration<br />
of the vehicle and its passengers (using seat belts)<br />
within limits. Where a large vehicle has, e.g., double the<br />
mass of a smaller vehicle, double the kinetic energy must<br />
be destroyed. This means-assuming the same front<br />
length (dcformation distance)--double hardness for the<br />
front structure (stiffness), or-assuming the same<br />
stiffness of the front (force level)-doublc thc length of<br />
front (or a combination of thesc two options).<br />
Where two vehicles are involved in a head-on crashfor<br />
the sake of clarity, only head-on collisions are<br />
considered hers-the change of velocity in the two<br />
vehicles results from the law of conservation of<br />
momentum applying to a plastic impact. This means-to<br />
remain with this example-in the case of an impact of 30<br />
mph per vehiclc and an assumed ratio bctwcen large<br />
vehicle mass and small vehicle mass of mL:ms=2: l, that<br />
the large vehicle continues driving in its direction at l0<br />
mph, while the smaller car is reversed and is pushed<br />
back by the larger vehicle at a speed of l0 mph. The<br />
large vehiclc undergocs a 20 mph change of velocity, the<br />
small vehiclc onc of 40 mph. Wc have a double change<br />
of speed in the smaller vehicle, whose normally softer<br />
structure must absorb double the energy.)r<br />
Now, it is also possible to optimize vehicle fronts for<br />
a collision involving two moving vchiclcs, i.c. not a wall<br />
crash (self-protection) but a collision between vehicles<br />
of different size (partner protection). Thc collision<br />
tolerance involved here is callcd compatibility. The<br />
dcsign for the fronts of *'compatible"<br />
vehicles would<br />
have to look as followst<br />
' The small car must share the deformation of the<br />
larger vehicle. This can be done by choosing dift'erent<br />
stiffness churacteristics (soft, medium, hard) or<br />
a linear increase in the stiffness characteristic for the<br />
front of lhc largcr car, at thc samc time tflking<br />
advantage of what will normally be greater fiont<br />
length and also a stiffer design in the front of the<br />
smaller car.<br />
. If these two vehicles-now designed for compatibility-collide,<br />
first of all the stiff front of rhe<br />
smaller vehicle crushes the soft section of thc front<br />
of the larger vehiclc. In thc proccss, the kinetic<br />
energy of the small vehicle is absorbed by the large<br />
vehicle. After that there is an even deformation of<br />
both vehicles.<br />
Now, however, there are drawbacks in the 30 mph<br />
impact test against the rigid barrier descrihcd carlicr for<br />
both vehicles. The small vehicle has been given a stiffer<br />
front design; as a result, the entire possible deformation<br />
path is no longer deformed; the mean deceleration and,<br />
hencc, thc strains on the occupants are higher. The large<br />
vehicle<br />
--gives<br />
away" opportunities for intaking energy.<br />
And although the choice of different degrees of stiffness<br />
can dcal with the impact of 30 mph against the rigid wall<br />
thanks to the longer front, a constant choice of stiffness<br />
and optimation of stiffness to cope with the barrier<br />
impact might have allowed the occupants to survive an<br />
impact involving a speed of perhaps 35 mph without<br />
serious injuries. So tar, vchiclc stiffncsscs have not yet<br />
lA double change of velocity nomally means quadrupling the kinetic energy to be absorbed. Ilowcvcr, this value is halved again, since rhe tlistriburion of<br />
masses is 2:l as indicated atxrve.<br />
104
' ' _:<br />
been optimized for the protection of people. However,<br />
there are approaches<br />
to solutions, e.g. in [3].<br />
Empirical Analyses<br />
Data Base<br />
In 1985, there were 77,009 accidents involving<br />
personal injuries between two cars in thc Fcderal<br />
Republic of Germany. Out of these, l-5,207 accidents<br />
with a total 28,757 casualties were accounted for by<br />
accident type'-Collision with an oncoming vehicle." 686<br />
of a total of 4,182 killed car occupants lost their lives in<br />
this accident type.<br />
This analyses are based on data for accidents<br />
involving personal injuries and serious car damage for<br />
the State of North-RhincAVestphalia, supplemented by<br />
automotive technology data available at the Federal Road<br />
Traffic Agency (Kraftfahrt-Bundesamt) []. Attention<br />
was paid in particular to the consequences of accidents<br />
for car drivers in accidents involving two passcnger cars<br />
(station wagons excluded) wilh an car age of less than l0<br />
yerrfs.<br />
The risk of injury for car occupants dcpends very<br />
much on whether seat belts were used. The rate of seat<br />
belt use on front seats of cars averaged 60Vo until the<br />
introduction of fines in August 1984, since when, the<br />
rate has been over 90To. In ordcr to rule out possible<br />
distortions owing to the diflerent rates, this study is<br />
confined to accidents occurring between August 1984<br />
and December 1988.<br />
In order to target the problem of compatibility with<br />
thc availablc data, the following remarks only concern<br />
accidcnts of type "Collision with an oncoming vchicle".<br />
By definition, therefore, the accidents to be considered<br />
here are collisions involving oncoming traffic without,<br />
e.9., one party intending to turn off to the left. In the<br />
period under review the accidents of this type in<br />
North'Rhine/Wesrphalia roralled 17,61?,.<br />
Study tlypotheses<br />
Compatibility problems always occur when large<br />
vehicles collide with smaller vehicles. The two main<br />
factors are:<br />
. different vehicle struclure optimized for selfprotection<br />
. different<br />
"mflss<br />
aggressiveness" of vehicles of different<br />
weights.<br />
This gives us the following two hypotheses:<br />
Ilypothesis /: Differenccs in vehiclc structure and<br />
i'mass<br />
aggressiveness" mean that thc consequcnces of an<br />
accident are less favourable for the occupants of the<br />
smaller and correspondingly more favourable for those<br />
in the larger vehicle.<br />
Hypothesis 2: Where the vehicles have the $ame structure<br />
and --mass<br />
aggressivencs$," this mcans that a<br />
head-on collision involving two small vehicles may be<br />
Sectlon 3: Tachnlcel Sesslons<br />
expected to have the same consequences as a head-on<br />
collision involving two large vehicles.<br />
C har ac t e r i sti c s for Assessin g t he S e r io usne ss<br />
of Injuries<br />
The central question concerns the extent to which the<br />
probability of serious conscqucnces for the car occupants<br />
depends on vehicle size. Since considerable variations<br />
are possible in the numbcr and seating position of<br />
co-driver and passengers, our sturly is confined only to<br />
drivers and to the consequences for them.<br />
For this study, the characteristic to indicate the mean<br />
seriousness of injuries to drivcrs involved in head-on<br />
collisions bctween two cars is the share of fatalities and<br />
serious casualtics amonB all drivers involved in accidents<br />
with personal injuries and serious material damage is<br />
chosen:<br />
, number of fatalities + seriously injured drivers<br />
AS=<br />
number of drivers in AI and AD<br />
AI = accidents with personal injuries<br />
AD = accidents with serious material damage<br />
With rcgard to this specific characteristic the<br />
statistically significant variable of whether the driver felt<br />
--guilty"<br />
or<br />
"not<br />
guilty" does not have to be taken into<br />
account in the statistical analysis (cf. t?l).<br />
Classilication by Weight Classe.r<br />
For the purposes of the present analysis, the vehicle<br />
population is subdivided by curb weight into four weight<br />
classes and the distribution is shown in Table l.<br />
Class l: cirr with an curb weight of 600 to 799 kg,<br />
Class 2: car with an curb weight of 800 to 999 kg,<br />
Class 3: car with an curb weight of 1,000 to I,199 kg,<br />
Class 4: car with an curb weight of 1,200 to 1,599 kg.<br />
Table l. Cars involved In headon colllslon betws€n<br />
two car$ in North-Rhine/Westphalia in ths perlod 1<br />
August 1984 to 31 Decsmbsr 1988, claesilied by curb<br />
weight (accidents with personal inluries and serious<br />
matsrial damagB)<br />
Citrs Involved<br />
Curb wcight (kg) Numbcr 7o<br />
600 to 799<br />
800 to 999<br />
10fi) to ll99<br />
1200 to 1599<br />
3,( 16<br />
14,0.t7<br />
9,795<br />
7.683<br />
8.9<br />
40.6<br />
28.3<br />
777<br />
Total 34,591 r00.0<br />
up ro 599/1600<br />
and more not known<br />
615<br />
l8<br />
.ir:<br />
:j;<br />
-
13th |/rternetlonel Technlcal <strong>Conf</strong>erence on Experlmentel Selety Vehlcles<br />
Classification by Design Features<br />
As stated above, stiffness and/or vehicle design, which<br />
vary from type to type, have considerable implications<br />
for the relative collision tolerance of the vehicles.<br />
Accordingly, two groups of vehicles were formed,<br />
taking account of empty weight and other design<br />
features:<br />
Group l: empty weight up to 999 kg;<br />
"small"<br />
traverse front engine;<br />
front-wheel drive<br />
Group 2: empty wcight up to 1,400 to 1,799 kg;<br />
"large"<br />
longitudinallyinstalledfrontengine;<br />
standard drive<br />
To form the above two groups, the empty weight<br />
classifications used deviate from thosc considered in<br />
<strong>Section</strong> 3.4. This was necessary in order to obtain<br />
sufficicntly large groups for study when two further<br />
vehicle design features are taken into account.<br />
Thc data material available for this study contains<br />
13,554 vehicles in Group I ("small") and 3,7-50 in Group<br />
2 ("large"). 8,742 of the 13,554 vehicles in Group 1<br />
(647o) concern the car models Ford Fiesta, Opel Kadett,<br />
VW Rabbit and VW Pokr, while 760/o of the vehicles in<br />
Group 2 (2,863 of 3,750 vehicles) concern the car<br />
modcls Mcrcedes Benz Wl23 and W124 and BMW in<br />
the 5. 6 and 7 series.<br />
Other Dercrminants<br />
Alongside the vehicle features<br />
*'vehicle<br />
struclure" and<br />
"mas$<br />
aggressiveness," there ate other important<br />
factors-e.g. velocity, age of occupants, etc.-which<br />
may have a more or less favourable impact on the<br />
consequences of the accident for the occupants.<br />
One factor of special importance fnr the consequences<br />
as they affect the occupants involved in a head-on<br />
collision is the speed at which the vehicles collidc. The<br />
data material available for the present analysis docs not<br />
explicitly include this feature, although we do know that<br />
the permissible max. speed and the mean speeds actually<br />
driven "inside built-up areas" are definitely below the<br />
values "outside built-up areas without autobahns" (rural<br />
roads). Alternatively, therefore, the factor "speed" is<br />
considered as explanatory variable via the feature<br />
"locality."<br />
Also included in the analysis as a further explanatory<br />
variablc is -'driver age," since the seriousness of injuries<br />
undcr Lhc same circumstance is, greater in the case of<br />
elderly people On the other hand, accidcnts involving<br />
younger drivers tend to correlate with excessive<br />
speeding.<br />
In a consideration of collision compatibility, vehicle<br />
age is important for two reasons:<br />
'old vehicles tend to be heavier and stiffer, which<br />
leads to special problems when a "light new" vehicle<br />
collides with an "old heavy" vehicle;<br />
. older vehicles have, normally a higher degree of<br />
corrosion than newer vehicles, so that the accident<br />
may have different consequences for the occupants.<br />
This was the reason to include only accidents with<br />
passenger<br />
cars of less than l0 ycars age.<br />
Variables (Ised in the Study<br />
In line with the rcmarks contained in thc prcvious<br />
sections, the analysis uses the following features as<br />
indepcndent variables (for dependent variables, see<br />
above):<br />
Curb weight class of the car under consideration<br />
(CARI) or the other car (CARZ)<br />
(1) 600 to 799 kg<br />
(2) 800 to 999 kg<br />
(3) 1,000 to 1,199 kg<br />
(4) 1,200 to 1,599 kg<br />
Alternatively:<br />
Size and design of the car under consideration (CARA)<br />
or the other car (CAR')<br />
(l) small<br />
(2) large<br />
Locality (L)<br />
(l) inside built-up area<br />
(2) outside built-up area without autobahn<br />
(rural roads)<br />
Age of driver in car under consideration (A)<br />
(1) under 25 years<br />
(2) 25 to 59 years<br />
(3) 60 years and oldcr<br />
The Statistical Analysis Method<br />
Thc counting ofthe fatalities and serious casualties for<br />
car drivcrs involvcd in head-on car crashes according to<br />
two or more variables produces a multi-dimensional<br />
matrix. The more variables are considered and the more<br />
catcgorics thc variablcs have, the more difficult it<br />
is-without adcquate analytical procedures-to identify<br />
the relevant structures and to distinguish essential<br />
influences from the inessential. This is specially true<br />
where the occupation of the cells in the multidimensional<br />
nralrix shows considerable varialion, i.e. if<br />
the malrix has cells with a high as well as cells with a<br />
very low occupation frequency.<br />
Statistical procedures based on logit models enable<br />
essential determinants to be identified using a<br />
multi-dimensional matrix; distinctions can be rnade<br />
betwecn significant and nonsignificant determinants.<br />
Non-significant dctcrminants can be excludcd from the<br />
analysis, i.e. unlike a *'conventional" evaluation<br />
involving a splitting up into multidimensional matriccs,<br />
the use of logit models allows parameters to be excluded<br />
wherever they are not stiltistically significant on the<br />
basis of cmpirical data [2].
Results<br />
Influence of "Locdliry"<br />
The variable "locality" has, as expected, a very great<br />
influence on the mean seriousness of injuries to drivers<br />
involved in head-on collisions between two cars.<br />
The pcrcentage of fatalities and serious casualties<br />
among drivers (relative to all drivers involved in<br />
accidcnts with personal injuries and serious material<br />
damage) is about three times higher in the case of<br />
head-on collisions between two cars on rural roads than<br />
in built-up areas.<br />
The inference is that the high mean seriousness of<br />
injuries on rural roads is basically statistically<br />
independent of the curb weight of one's own car and of<br />
thc curh weight of the other car. Thus, the variable<br />
"locality"<br />
acts as a constant factor on the mean<br />
seriousness of injuries; the relative increasc in the<br />
percentage of fatalities and serious casualties among<br />
drivers is equally high for all "curb weight classes."<br />
In view of the high explanatory value of thc variable<br />
"locality"<br />
accounting for the percentage of serious<br />
consequences, this variable is further considered again in<br />
the model.<br />
Influence of Driver Age<br />
The indcpendent variable "driver age" has only a<br />
comparatively slight influence on lhe mean scriousness<br />
of injuries from head-on collisions. Of the three<br />
categories of the main effect, only the third category<br />
-'drivers<br />
agcd 60 years and more" is significantly<br />
different from 0 (a < 0.05) and has a positive sign. This<br />
means that the percentags of fatalities or serious<br />
casualties among "old" drivers involved in head-on<br />
collisions is higher than the percentage of young drivers<br />
or middle-aged drivers. The absolutc amount of this<br />
estimated value is small, however, relative to the values<br />
of the other parameters in the model, cspecially the<br />
--locality"<br />
variable.<br />
Since no interactive effects significantly different from<br />
0 occur bctween the three categorics of the fcature<br />
"driver<br />
age" irr the car under consideration and the other<br />
paramcters contained in the model, the inference is that<br />
a higher mean seriousness of injuries can only be<br />
established for older drivers, regardless of locality and<br />
the weight of one's own car and the weight of the other<br />
car.<br />
An additional study of the connection between car<br />
driver age and car weight has shown that the percentage<br />
of older drivers increases markedly with the curb weight.<br />
In order to avoid any distortions to the results from a<br />
correlation between these two variables, the analyses in<br />
the following <strong>Section</strong>s ignore drivers aged 60 and older.<br />
As was already established, thc same accidcnt<br />
consequenccs can be expected for young and middleaged<br />
drivers involved in head-on collisions berween two<br />
cars. Thus, if we ignore older drivers, the feature "age of<br />
Sectlon 3: Technlca/ Sessions<br />
driver of car considered" need no longer be considered<br />
in the analysis.<br />
Serinusness of Head-on Crasftes Involving Two Cars<br />
as a Function of Weight<br />
Bcfore dealing with the question of the coltision<br />
compatibility of cars in the following <strong>Section</strong>s, the<br />
present <strong>Section</strong> examincs the mcan seriousncss of<br />
injuries to drivers involved in head-on crashes between<br />
lwo cars as a function of the weight of one's<br />
'-own" car;<br />
the wcight of the -'other"<br />
car is left out of account in rhis<br />
first analysis.<br />
Figure I shows a curve for the mean serir)usness of<br />
injuries to drivers involved in head-on crashes between<br />
two cars that falls with the curb weight of thc car. The<br />
seriousness of the consequences fall substantially with<br />
the rise in the weight of the car undcr consideration. The<br />
percentage of fatalities and serious casualtics among<br />
drivers of cars with 600 kg curb wcight is l4.2Vo; and<br />
that for drivers in cars with an curb weight of 1,500 kg<br />
is 4.890.<br />
t<br />
.l<br />
! f<br />
at<br />
5<br />
I t<br />
E a<br />
t<br />
E<br />
t<br />
IE<br />
o<br />
T<br />
I<br />
I<br />
{<br />
6<br />
f<br />
. 1 0<br />
i<br />
E a<br />
t<br />
E<br />
A<br />
i<br />
as 1t0 m $0 tm 1100 lil l3E rr00 lEm lcm<br />
Gurb wrrhht of crr rurdcr conrlderetlon [k9]<br />
84S - ul -aEUl<br />
Flgure 1. Serlou*nese of heed.on craehee involving two<br />
cf,r8 on tural roads ee function ol the curb weight of the<br />
two csrs (driver age up to 59 years)<br />
Compatihility in a Consideration of Four Weight<br />
C/asses<br />
To describe the collision compatibility of car$, a<br />
model is estinrated in what follows that takes as
lSth lnternatlonal Technlcal <strong>Conf</strong>erence on Expeilmental Safety Vehlcles<br />
independent variables the feature "locality" and the car<br />
under consideration and/or the other car (each in four<br />
weight classes). The dependent variable considered is thc<br />
percentage of fatalities and serious casualties among<br />
drivers relative to all drivers involvcd in accidents with<br />
pcrsonal injuries and serious material damage (AS).<br />
Using this model, we can cstimate expected values for<br />
the seriousness of accidents and the relevant confidence<br />
intervals for all covariable constellations. Fig. 2 shows<br />
the results for the rural road sector.<br />
In thc following the two hypotheses for the collision<br />
compatibility of cars involved in head-on collisions<br />
described abovc were tested (see Annex Table Al and<br />
A2 and Figure 2):<br />
Hypothesis I says that, in accidents involving cars of<br />
different weight, different "mass aggressiveness" can<br />
lead to more serious consequcnccs of the accident for the<br />
occupants ofthe smallerand correspondingly less serious<br />
consequences for those in the larger vehicle. This<br />
hypothesis can only be maintaincd partly;<br />
. Figure 2 makes it clear that seriousness of the<br />
consequcnces of the accident for thc driver is relatcd<br />
quite definitely to thc curb weight of his own car.<br />
The conscquences for drivers in cars with an curb<br />
weight of 600 to 799 kg are-regardlcss of the<br />
weight of thc other car-some 2.5 times less favourable<br />
than for drivers of cars with an curb weight of<br />
1,200 to 1,599 kg.<br />
E<br />
5<br />
e<br />
E ca<br />
.t<br />
t<br />
t<br />
I<br />
+o<br />
t<br />
t<br />
e<br />
.t<br />
E<br />
a<br />
{<br />
E 9I<br />
6<br />
t00 ?00 ts lfr 1000 1100 tlm 1900 1.00 tt00 rt00<br />
curb wcght of othrt crr lkgl<br />
r a.u.-r.ilr.<br />
Figure 2. Compatibility+xpected yalues for the<br />
seriousnees of accidente in head-on creshe$ involving<br />
two cers on rural roads, ae functlon ol the curb weight of<br />
both cars (driver aga up to 59 years)<br />
108<br />
Gut wrlght of cer<br />
mdcr conrldrrutlon lkgl<br />
On rural roads, for example, the expected value for<br />
the percentage of fatalities and scrious casualties<br />
among drivers in cars with an curb weight of 600 to<br />
799 kg in the case of hcad-on collisions with a car<br />
of 800 to 999 kg curb weight is 20.87o, with a car of<br />
1,200 to 1,599 kg curb weight 22.9Vo; the corresponding<br />
expected values for drivers in cars with an<br />
curb weight of 1,200 to 1,599 kg, however, are only<br />
8.27o (wcight of othcr car 800 to 999 kg) and 9.77o<br />
(weight of other car 1,200 to 1,599 kg) resp.<br />
. Within the various curh weight classes, however,<br />
hypothesis I can be confirmed in principle; it can be<br />
seen, e.g.r thal, in the case of drivers of cars with an<br />
curb weight of 800 to 999 kg involved in head-on<br />
collisions with a smaller car (600 to 799 kg weight),<br />
the consequences for the car with 800 to 999 kg curb<br />
weight are much less serious (l3.4qo) than in the<br />
case of a head-on collision with a heavicr car (1,000<br />
to 1,199 kg curb weight l5.5Vo and 1,200 to 1,599<br />
kg curb weight l8.3Vo).<br />
Hypothesis 2-equal "mass aggressiveness"-viz. that<br />
thc consequences of a head-on collision betwccn cars of<br />
equal weight classes are approx. the same for the<br />
occupants, cannot be confirmed. In fact, Fig. 2 shows<br />
that the seriousness of thc consequenccs for the driver<br />
depends quite subslantially on the curb weight of his<br />
own car. The values of the characteristic for the seriousness<br />
of injuries AS fall strikingly as the weight of the<br />
car under consideration increases. The expccled value for<br />
the percentage of fatalitics and serious casualties among<br />
drivcrs in head-on collisions involving two cars with an<br />
curb weight of 800 to 999 kg is 14.8%; in head-on<br />
collisions involving two cars with an curb weight of<br />
1,200 to 1,599 kg, the figurc is9-7Vo.<br />
Compatibility in a Consideration of Two Selected<br />
Vehicle Groults<br />
To take account of these conditions, two vehicle<br />
groups ("small"/--large") were selected by size and<br />
design features, for the car under consideration and the<br />
other ciu-as independent variables and includcd in the<br />
multivirriable analysis. The feature "locality" was<br />
considered as a further indepcndcnt variable. The<br />
dependent variable is again the pcrcentage of fatalities<br />
and serious casualties relative to all drivers involvcd in<br />
head-on crashes with pcrsonal injuries and serious<br />
material damage-<br />
As stated above the consequences of head-on<br />
collisions are many times less favourablc for drivers on<br />
country roads than they are insidc builtup areas,<br />
regardless of the size and design of the vehicle. The<br />
accident severity (AS) for small and large cars is shown<br />
in Fig. 3. The hypotheses I and 2 for the collision<br />
compatibility of the cars can be checked again.<br />
Overall, it can be said that the results obtained by<br />
classifying the vehicle populations into four cmpty
weight classes for the car under consideration and the<br />
other car by postulating two vehicle groups based on<br />
masses and design features, were corroborated; in the<br />
case of head-on collisions involving a small and a large<br />
car, the mean seriousness of the injuries is some 2.5<br />
times greater in the large car.<br />
Eurlt-uF Af+rs iurrl Isi!<br />
trtr trtr<br />
1,3<br />
3. t<br />
t.9<br />
z,t' o,t<br />
t,a<br />
6,7<br />
5 t2<br />
8,1<br />
3,2<br />
8,6<br />
t, o'<br />
ll,1<br />
5,4<br />
I t,5<br />
r7 ,1<br />
r 5,7<br />
tJ. ?<br />
lr.s<br />
| 7,8<br />
Crr. Crtr<br />
-/frfr ..=A<br />
€HF<br />
-Ffi'ifr<br />
,,4r="<br />
rcF4{t #<br />
/TiL.<br />
ITCTHF<br />
tr AS =.Pffit grof faulitieurl rcrimrcssudtiB Etidwtodt ddw lnwlvcd<br />
= in accidcnts wilh permnal injurics md srious nraterial damrgc<br />
12l 95 1& corfidene interyal<br />
T In this mnsl€llation, only I fatalities or sdously injured drivers wcrc ltrorded<br />
Figure 3. Expected value for setiousnsss of accidents<br />
lnvolvlng car drivers In head-on crash€s (accident<br />
type 4) betvrrgn two cars ln built-up and on country<br />
roads as a function of two selected vshicle group$<br />
(accident with pereonal inluries and material damage;<br />
drlver ege up to 59 years)<br />
Summary, Discussion of the Results<br />
Head-on crashes between cars are particularly serious.<br />
Where large and small vehicles collide, physical theory<br />
leads to expect compatibility problems. The main factors<br />
rcgarded as underlying the special collision intolcrance<br />
of vehicles of different sizes are the different vehicle<br />
structures optimizcd for self-protection and the different<br />
**mass<br />
aggressiveness" of vehicles of different weights.<br />
In 1985, there were 77,009 accidents involving<br />
personal injuries between two cars in the Federal<br />
Rcpublic of 6ermany. Out of the.se, 15,207 rccidents<br />
with a total 28,757 casuirlties were accounted for by<br />
accident type "Collision with an oncoming vchicle." 686<br />
of a total of 4,182 killed car occupants lost their lives in<br />
this accident type.<br />
The analysis undertaken in this report is based on the<br />
data for accidents involving personal injuries and serious<br />
material damage in the State of North-RhineAilestphalia,<br />
supplemented by automotivc data available at lhc Federal<br />
Road Traffic Agency. In order to rule out flny distortions<br />
due to diffcrences in rates of seat belt use, the study is<br />
confincd to accidcnts occurring after August 1984. Since<br />
then, the rate of seat belt use in the Federal Republic has<br />
Sectlon 3: Technlca/ Sesslons<br />
avemged well over 90%. The vehicle population was<br />
broken down by curb weight into lour weight classcs.<br />
The assessment criterion in the statistical analysis was<br />
the mean seriousness of injuries to drivers involved in<br />
head-on collisions between two vchicles. The independcnt<br />
variables considered in addition to the features<br />
"curb "of<br />
weight class of the car under consideration" or<br />
the other car'- were lhe features<br />
-'locality"<br />
and<br />
--age<br />
of<br />
the driver of the car under consideration."<br />
The statistical analysis was madc using logit models,<br />
which enable the key determinants to be identified and<br />
their impact quantified within the scopc of multidimcnsional<br />
analysis. As expected, the featurc<br />
"locality"<br />
has a grcat impact on the mean scriousness of injuries to<br />
car drivers involved in collisions with oncoming cars;<br />
regardless of curb weight class of the vehiclc, the<br />
conscqucnccs o[ accidents for drivers on rural roads are<br />
about three times less favourable than in the case of<br />
built-up areas.<br />
The feature "age of driver in the car under<br />
consideration" has a comparatively slight impact on thc<br />
mcnn seriousness of injuries to drivers involvcd in<br />
head-on collisions betwccn two cflrs. In the case of older<br />
drivers, however, there is in fact a higher mean seriousness<br />
of injuries, regardless of locality and the curb<br />
weight of their own or the other car.<br />
Study hypothesis l, viz. that different ddmflss<br />
aggressivene$!i" in accidents involving cars of different<br />
weights produces more seriouri consequences for the<br />
driver of the smaller car-and correspondingly less<br />
serious consequcnccs for thc drivcr of thc larger<br />
vehicle-were only confirmed with reservations.<br />
Study hypothesis 2, viz. that equal "mflss<br />
aggressiveness" produces approx. the same consequcnces<br />
for car occupants in head-on collisions involving<br />
cars of the same weight, was not confirmed.<br />
In fact, thc cmpirical analysis showed that the<br />
$eriousness of the consequences for drivers was<br />
associated on average and quite significantly with the<br />
curb weight of thc driver's own car. Thc mean<br />
seriousncss of injurics is some 2.5 timcs as high for<br />
small cirrs or for cars with a weight between 600 and 799<br />
kg-rcgardlcss of thc wcight of thc othcr car-as it i$<br />
for large cars or for cars with an curb wcight between<br />
1,200 and 1,599 kg.<br />
The same results could be obtained by only looking to<br />
small cars (< 1000 kg) with trflverse engine and large<br />
cars (> 1400 kg) with longitudinally installed engine.<br />
Thus, there must be other factors operating to explain<br />
why safcty is very much greater for the occupants of<br />
large vchiclcs than it is for small vehicles. One possible<br />
explanirtion is that thc intcrior appointments of largeand<br />
hence more expensive-cars offer more scope or the<br />
use of safety-enhancing features. For example, the use of<br />
energy-absorbing materials in the interior (e.g. dashboard),<br />
the installation of safety steering wheels, etc. is<br />
109
13th lnternatlonal Technlcal <strong>Conf</strong>erencF on Experlmental Satety Vehlcles<br />
easier to implement cost-wise for large cars than it is for<br />
small cars. Differences in car safety for different cars<br />
within each weight class cannot be made by means of the<br />
data base used for this studv.<br />
[4] Evans, L.; Wasielewski, P.; 1987: Serious or Fatal<br />
Driver Injury Rate vs. Car Mass in Hcad On Crashes of<br />
Similiar Mass. In: Accident Analysis and Prevention,<br />
Vol. 19, Nr. 2.<br />
References<br />
lll Bock, O.; Brtihning, E.; Dilling, J.; Ernst, G.; Miese,<br />
A.; Schmid, M.; 1989: Aufbcrcitung und Auswertung<br />
[5] Langwieder, K.; Schmelzing, W.; 1982: Kollisionen<br />
von Pkw unterschiedlicher Masse. BMFT Statusscminar.<br />
Miinster 1982.<br />
von Fahrzeug- und Unfalldaten zur Hebung der<br />
Verkehrssicherheit. Gemeinsamer Bericht der<br />
[6] Nygren, A.; Gustafsson, H.; Tingvall, C.; lg82:<br />
Injury Frequency and Injury Panorama among Drivers-<br />
Bundesanstalt fiir StaBenwesen und des Kraftfahrt-<br />
Bundesamtes Herausgegeben im Auftrag des Bundesministers<br />
fiir Verkehr von der Bundesanstalt fiir<br />
A Comparison bctwecn Small and Big Cars and the<br />
Influence of Year Model and Production Start. 7.<br />
IRCOBI Konferenz, Koln 1982.<br />
StraBenwesen, Bereich Unfall-forschung, 1989, Heft 71.<br />
[2] Bruhning, E.; Ernst, G.; 1988: Loglinear and Logit<br />
Modells in Accident Research. 9. IRCOBI Konferenz.<br />
Bergisch Gladbach. In: 1988 <strong>Int</strong>ernational IRCOBI<br />
<strong>Conf</strong>erence on the Biomechanics of Impacts, S. 35 - 46.<br />
t31 Danner, M.; Appel, H.; Schimkat, H.; 1980:<br />
Entwicklung kompatibler Fahrzeuge. Abschlubericht des<br />
BMFI. 1980.<br />
[7] William, Bochly, Lombardo (NHTSA); 1980: Safcty<br />
Consequences of the Shift to Small Cars in the 1980' s.<br />
8. <strong>ESV</strong> Konferenz, Wolfsburg 1980.<br />
18l Ernst,G.,Bruhning,E., Glaeser,K.-P.,Schmid,M.;<br />
1991 Safety in Small and Large Passenger CaTs,IRCOBI<br />
<strong>Conf</strong>. Potsdam, Sept. 91.<br />
Annex<br />
110<br />
tlbtc ltl Expccred vtluc for *riousncsr of accidcnts involving cat drivcn in hcadon<br />
crashes between two cats lnsiile built-up sFeas es e function of four curb<br />
weight classes (Accidents with personal injuries and serious material<br />
damage;driver age up to 59 years)<br />
Table A2:<br />
Eurb slght of<br />
cffild.r.d ull<br />
*<br />
,'ir- *t<br />
lsl) c6tldm.-<br />
L lrltri)<br />
* to o,t! g.s*) E'e<br />
z.E<br />
*o to *.1!<br />
t.I<br />
1000 to lt9t(ke 2.9<br />
1200 to 15t9 kr<br />
(4)<br />
r.t*)<br />
5.e<br />
1.8<br />
5'5<br />
t.r<br />
Cwb Fi<br />
Ano tq 999 kl<br />
(e)<br />
lst) cfrlld.r.-<br />
6-7<br />
t<br />
3,2<br />
2.4<br />
t irit*l)<br />
t.5<br />
5.1<br />
5.1<br />
t.9<br />
t-7<br />
2.6<br />
2.9<br />
t,6<br />
$t of oth.r CrtI2<br />
1000(to ll99 kl<br />
lsl ) cfflid.H-<br />
t,1<br />
4,8<br />
3.6<br />
llritrt)<br />
!.9<br />
5.5<br />
5.5<br />
1.1<br />
l) 15 * Frcmtrgc ol fltstltld ud trflM cotuttirs rlLltlyr to rtI drlwrr<br />
e.6<br />
4.t<br />
2.9<br />
3.2<br />
4.0<br />
It00 to)1599 le<br />
tsl ) cmf tdsrcrt<br />
lrl trZ)<br />
7.t<br />
5.8<br />
4,!<br />
z.t<br />
9.6<br />
J.4<br />
6.7<br />
6.8<br />
J.f<br />
1.9<br />
t.6<br />
a.l<br />
lruotved ln lccidenti rlth rrrmt lRjdls rd rerlm drnlcrl dmoge<br />
?) 95 I cfffid€ftr lnt.rv6L<br />
r) Ih tha coffitaLtatlff, larar than l0 latatltlo or arrlM ca6sttld *ra r*ordad<br />
Expected value for seriousness ofaccidents involving car driven in hFqd-on<br />
crashes between two cars on rurnl roads as a function of four curb weight<br />
(Accidents with personal injury and serious material damage; driver age up<br />
to 59 years)<br />
:urb slght ot<br />
:ffii&rd iltl<br />
600 to 79t kr<br />
il)<br />
*o to *.!!<br />
1000 to ll99(ki<br />
1100 to 1599(ts<br />
* li)* *'<br />
Atl) cfrfidctrc<br />
r7.5<br />
13.4<br />
9.9<br />
, 7<br />
t lni trl)<br />
26.0<br />
9.0<br />
1t,z<br />
9.6<br />
tr.6<br />
6.!<br />
il.4<br />
4.0<br />
Eurb<br />
*o l!,* *'<br />
AEI) cfrfidcric.<br />
t tri tcl )<br />
e0.E<br />
t4.8<br />
t0.t<br />
6.4<br />
rllht ol oth.r ffi;<br />
1000(to lll4 kt<br />
451) cmf ldcmr-<br />
t lrltrZ)<br />
27,t<br />
et.8<br />
16.4<br />
lzo{t to)1599 kr<br />
rsl) cmlldrmr<br />
t lrl trl)<br />
e0"t<br />
22,o<br />
16.4<br />
ll AS r percmtogc of f.trtitlGr x1d rcriffi c.asltl.r ritltivc ta ltt drlwrr<br />
lnvotvd ln rFcidmts Hith Frrmt lnjuriH..rd r.rlruc dtyEiGrt dme.<br />
2t 95 t cnfldrtr. <strong>Int</strong>prvEt<br />
25.6<br />
t6.0<br />
16,5<br />
rl,0<br />
ta.t<br />
9'0<br />
10.0<br />
6-(<br />
t5.t<br />
r?.0<br />
8.9<br />
17 '6<br />
tt.t<br />
t4.E<br />
9.9<br />
11.0<br />
6.6<br />
18.!<br />
r5.5<br />
9,7<br />
2t.0<br />
t5.6<br />
1E.t<br />
12,7<br />
t2. I<br />
f.2
st.o.t4<br />
Survey of Car-To-Fixed-Obstacle Fatal<br />
Cleude Henry, Serge Koltchakian,<br />
Gdrard Faverjon, Jean Yves Le Coz<br />
Laboratory of Accident Research and<br />
Biomechanics<br />
Associated with Peugeot SA/Renault SA<br />
Alain Patel, Claude Got<br />
Orthopaedic Research Institute<br />
Abstract<br />
The main factor of over-risk related to road infrastructure<br />
is fixed roadside obstacles. Due to their high<br />
stiffness, they represent a major danger in the event of<br />
loss of car control.<br />
In France, on the road network outside of urban areas,<br />
about one third of lhe car fatalities recordcd in 1990<br />
werc in crashes against fixcd objects, and involved about<br />
1600 fatalities. As far as trees alone are concerned, it<br />
should be emphasized that 900 fatalities are related to<br />
this kind of obstacle, mostly for lines of trees along the<br />
roadside.<br />
Impact charactcristics will be given lor primary safety<br />
factors (circumstances, road conditions, drivcr state, etc.)<br />
and also for secondary safety aspects (impact types,<br />
violence of impacts, intrusion frequcncy, ctc.).<br />
Expected benefits (saved lives) from road infra-<br />
$tructure improvements by using guardrails, principally<br />
in front of tree$. are studied on the brsis of extensive<br />
and well-documented fatal crash policc rccords establishcd<br />
by the police force network over 6 months for all<br />
of France.<br />
<strong>Int</strong>roduction<br />
As a joint initiative of the Orthopaedic Research<br />
Institute of Garches Hospital and the Laboratory of<br />
Accident Research and Biomechanics Associated with<br />
Peugeot SA/Rcnault SA, it was underti*en to collect the<br />
police records of fatal crashes occurring in France on the<br />
entirc road network, over one year from lst March 1990<br />
to 28 February 1991.<br />
The present study is devoted to the analysis of fatal<br />
crashes of passenger car occupants against fixed<br />
obstacles, occurring over six months on the network<br />
monitorcd by the National Police Force.<br />
Of the 6295 deceases of passenger car occupants<br />
counted in France in 1990, the National Police Force [l]<br />
recorded 5014 (8070 of all motorist fatalities), of which<br />
2618 occurred between lst March and the 3lst August<br />
1990. At present, more than 90Vo of the crash reports<br />
concerning these victims have been transmitted to us,<br />
and for 2374 of the 2618 fatalities. we have been able to<br />
break down the victims according to the type of crash<br />
lTable ll.<br />
Crashes<br />
Sectlon 3: Technical Sessions<br />
Table 1. Breskdown of ilbtorist Fatelities According to<br />
ths Nature of the Accident in Frence, from the 1st March<br />
to the 31$t August 1990, on the National Police Network*<br />
;AR.TO-CAR<br />
NATURE OFEE<br />
:Ah ACAINST A UTIUTY VEHICG<br />
]AR AGAINST frHER VEHICLE<br />
ACCIDffi<br />
ROLTOVER, OVftTUNNG OF CAR<br />
frHERS (rubmffiion,<br />
Hl irh tully, +c,)<br />
MOTORIST FATAI-[IS<br />
NUMBER *<br />
666<br />
451<br />
4l<br />
?41<br />
.13<br />
4u<br />
6il<br />
2E,l<br />
l9.l<br />
31.,<br />
17.1<br />
t3.E<br />
l?.t<br />
T([AL 2314 lm,0<br />
'Road network located outside ol urban areae, coneieting of the<br />
network in lhe open countryside and the network passing through<br />
smell end medium-size towns.<br />
Crashes against fixed obstacles and crashes<br />
"with<br />
no<br />
obstacle" represent morc than half of all falalities. Fixed<br />
obstacles alone arc the causc of closc on one third of<br />
deceases (31.27o).<br />
Out of 100 fatalities against fixcd obstacles, the<br />
obstacle is a tree in 56Vo of cases. whereas walls and<br />
poles alone represent more than half of the remaining<br />
44-7t' af fatalities.<br />
By comparison, impacts against tixed obstacles on the<br />
entire road network in the U.S.A. caused 36.6Vo of the<br />
25,046 motorist fatalities in 1989 [2], wittr the obstacle<br />
being a tree for only a quarter of these deceases.<br />
An exhaustive study of fixed obstacles requires a good<br />
assessment of impact conditions. This obviously requires<br />
that the crash reports be sufficiently well documented<br />
with photographs of the vehicles and the environment.<br />
Accordingly, we had to exclude from the basic samplc,<br />
consisting of 413 tirtalities in crashes against trees and<br />
328 fatalities in crashes against other fixed obstaclcs, a<br />
small number of victim.s for which the files wcrc<br />
insufficiently documented. The samplc adopted consists<br />
of 691 fatalities, involved in 582 fatal crashes against<br />
fixed obstacles, with trees rcprcscnting -577o of deceases<br />
lTable 21.<br />
Table 2. Fetel Accident$ Ageinst Fixed Obstacles:<br />
Breakdown of Graehes and Casualties Against Trees or<br />
Other Fixed Obstacles in the Basic Sample<br />
I ret^r sEvEE u6ffi sEvEm rd&<br />
ffi cE | "*"L<br />
rerrme<br />
*juo* IMUHE UNMME<br />
uHnows<br />
Nuug4o"<br />
-'-__- {.4(lrP^ffi<br />
ruES -<br />
ffiER<br />
OMASLE<br />
TtrAL<br />
3?t fl l2l 6r ll ! 5v<br />
T e f r l c n x l 2 5 f i<br />
5n er m l3l 4l J lls<br />
2.6<br />
lll
lSth lnternetlonel rechnlcal conference on Experlmentel sefety vehtctes<br />
Part one of this study is devoted to analysis of the<br />
main data (characteristics of the locations, obstacles<br />
impacted, types of impacts, driver-related data, crash<br />
conditions for motorist fatalities).<br />
Part two contains, on the one hand. an evaluation of<br />
the number of fatalitics which could have been prevented<br />
with 1007d wearing of the seat belt (or another appropriate<br />
restraining system), and on the other hand an a priori<br />
evaluation of thc potential safety benefits from protecting<br />
the obstacles, especially trces.<br />
Main Characteristics of Fatal Crashes<br />
Against Fixed Obstacles<br />
l<br />
The results mentioned in part one of this study are<br />
based either on the observations of the national police<br />
force, or on crash research analysis carricd out by our<br />
specialists at the laboratory.<br />
With respect to the characteristics of locations, the<br />
following points should be noted.<br />
. Close on 807o of crashes against fixed obstacles<br />
occurred outside of urban areas. The network of<br />
departmental roads reprcscnts 58Vo of all crashes,<br />
and the main highways 32%,. Out of 100 crashes, the<br />
day/night breakdown is as follows:47Vo by day and<br />
53Vo by night [Table 31.<br />
Table 3. Fatal Greshee Agalnst Fixsd Ob$tacles: Types of<br />
Road Networks, Road Categories and Luminosity<br />
ttz<br />
N-?m)<br />
Its - s4)<br />
^-hF.E4nnnrErtH-31t)<br />
(r4r)<br />
t<br />
3<br />
.a<br />
n<br />
t<br />
ill2t<br />
l6<br />
s<br />
arcllT<br />
t0<br />
* 7<br />
l?<br />
t21)<br />
7<br />
4<br />
(2)<br />
tq<br />
] It<br />
fi lm<br />
. Trees represent more than half (55.57o) of the<br />
obstacles impacted, followed by walls (13.67o), poles<br />
and embankmenls/ditches + pipes located in the<br />
ditches. The 2.4V0 of impacts against guardrails is<br />
far below the proportion observed in the U.S.A. t2l,<br />
where this figure is close on l07o [Table 4].<br />
{l)<br />
ll<br />
la<br />
Tsble 4. Brcakdown ol Fatal Crashes Against Fired<br />
Obstaclea According to Type of Obstacle<br />
TREE<br />
MAIN OBSTACLE<br />
-.6 < 0.40 m<br />
-d0.40 to 0.60 m<br />
-g > 0.60 trr<br />
WALL, BUILDINC<br />
ELECTRICITY OR TELEPH<strong>ONE</strong><br />
FOIE<br />
DUC I' (in diEh)<br />
EMBANKMENT, DITCH<br />
BRIDCE RA]L<br />
GUARI]RAIL<br />
LAMP POST<br />
OTIIERS<br />
FATAI CRASHES<br />
NUMBER %<br />
108<br />
120<br />
95<br />
?9<br />
60<br />
3{t<br />
28<br />
2l<br />
t4<br />
7<br />
20<br />
55.5<br />
t3.6<br />
10.3<br />
5 ?<br />
4.8<br />
3.6<br />
2.4<br />
1.2<br />
3.4<br />
lm%<br />
. Crashes occur in the straights in 43Vo of cases, as<br />
against 54Vo in curves (including entry and exit),<br />
mostly in left-hand curves. ln lTVo of crashes, road<br />
adhesion was degradcd (wet surface, snow, etc., or<br />
deformed roadway, loose gravel, ctc.). We specify<br />
thflt climatic conditions were particularly mild<br />
during the period over which the cases were selected-<br />
In 52Vo of cases, thc obstacle is located on the<br />
lcft road shoulder relative to the car's dircction of<br />
travel [Tablc 5].<br />
Table 5. Position, in Relation to the Initiat Direction of Car<br />
Travel, ol the Fixed Obstacle lmpacted as a Function ol<br />
the Foad Layout and the Condition of the Roadway<br />
' s(iieil ffirioi (ldJ)<br />
(8?)<br />
\721<br />
od.c (t)<br />
ROAD<br />
srEishr $.rion (E )<br />
rct Nfrc<br />
(96)<br />
li8hr ru,rE (6)<br />
orhcB<br />
(10)<br />
r (Jnd.Ehind<br />
A - IilrprB rrdil* krr! lN<br />
" l?l'l<br />
DRY ROADWAY. IN COOD CONDITION<br />
(N = ?tr)<br />
4l<br />
t4<br />
I<br />
16<br />
31<br />
DRY ROADWAY, IN OOOD CONDITION<br />
(N = 14)<br />
{N - lr2)<br />
5l<br />
a. h@ Fid e fird dtulq (H ' SE+)<br />
in I ciE<br />
(N -- l0r)<br />
It<br />
JI<br />
3l<br />
5<br />
WgT NOAL]WAY. SNOW... AND/OR<br />
IN BAD CONDITION<br />
(N - 57)<br />
9<br />
5<br />
6<br />
lN - 16l<br />
5<br />
l5<br />
wHt RoAtlwAY, sNOW... AND/OR<br />
IN BAD CONDITION<br />
6<br />
8<br />
J<br />
6<br />
lz
. When the obstacle is a tree, the tree is isolated in<br />
anly lUVo of cases, while in two thirds of the cases<br />
it is located in a plantation bordering the road. Large<br />
plantations such as clumps of trees and forests<br />
represent close on one quarter of crash cases. In the<br />
case of trees lining the road, the average spacing<br />
between 2 trees is less than or equal to 10 metres in<br />
55Vo of cases. between l0 and 20 metres in 407o of<br />
cases, and greater than 20 metres in 5Vo of cases.<br />
The tree is located at a distance less than or equal to<br />
I metre from the edge of the roadway in one third of<br />
cases (457o lor rows of trees only), and more than 3<br />
metres from the roadway in close on one case in<br />
four [Tablc 6].<br />
Tabb 6. Dletrncs Between lmpacted Obstacle<br />
and thc Edge of the Roedway<br />
FATAL CRASHS<br />
AlAIN5T.Tffi<br />
DISTANCE (IN ftUH) EffWEEH NE OB5TACLE<br />
AND lHE (l.li ornthl) EDCE OF THE ROALIWAY<br />
-T-__r__I-__-_-__r______T-<br />
.{r.0<br />
ALt- CMSHE IE<br />
EAIALIFASIIIA<br />
MSUIXEB<br />
lE!!<br />
oltscLs'<br />
r0<br />
9J<br />
l<br />
I<br />
I Ll-:,o i 2.r-r.0 I J.r-{.0 I<br />
s (29,r)<br />
l0<br />
n 7<br />
I<br />
a3<br />
{13.J)<br />
7<br />
5<br />
6<br />
^I.I. CRASIIE 4l<br />
fl6.?) (?4.5) d2,6)<br />
7l<br />
(6,4<br />
l<br />
9<br />
I<br />
I<br />
It<br />
(9.7)<br />
}1.0<br />
I<br />
at<br />
(r4.9)<br />
1<br />
l7<br />
2l<br />
68<br />
(26.5)<br />
rmAt<br />
$u (|fi *)<br />
Jl (t0.: i)<br />
lll (65.9 i)<br />
10 (r2.4 r)<br />
l? ilt.J *l<br />
B?<br />
tro r)<br />
Analysis of the 582 fatal crash reports shows that<br />
frontal impact is the most frequcnt configuration,<br />
representing more than 50Vo of cases, both for impacts<br />
against trees and impacts against other fixed obstacles<br />
lTable 71. Side impacts represcnt SlVo o[ crashes (all<br />
fixed obstacles combined) and crashes of an "unclassifiable"<br />
type (car impacting an obstacle during a rollover<br />
or overturning) represent close on lSVo of crashes.<br />
By means of the photographs cncloscd with the police<br />
reports, we establishcd, for all frontal and side impacts,<br />
a distribution of overlaps (arcas of main deformation) of<br />
the front (or side) with the obstacle. A fairly precise<br />
evaluation of the E.E.S. (Equivalent Encrgy Spccd) was<br />
made for close on 80Vo of frontal impacts, while a more<br />
difficult (and therefore more approximate) evaluation<br />
was made for about two thirds of side impacts.<br />
The following aspects are noteworthy.<br />
In Frontal Impact, the impacts with thc greatest offset<br />
(7/4 overlap type with deformations affecting the front<br />
wheel and the side of thc passcnger compartment, and of<br />
l/3 overlap type in which a longitudinal member was<br />
subjected to loading) represent SQVo of all impacts.<br />
Impacts in which the deformations affect (at most) half<br />
of the car concern 6l%o of impact$ against trees anrl 44o/o<br />
of impacts against other fixed obstacles. Finally, irnpacts<br />
Sectlon 3: Technlca/ Sess/ons<br />
Tabh 7. Brsakdown ol Fatal frrshes Agtlnst Fixsd<br />
Obstaclee According to Type of lmpact<br />
FATAL CBASHES<br />
AGAINST TREES<br />
FATAL CRASHES<br />
ACAINST OTHER<br />
FIXED OBSTACLES<br />
TYPES OF IMPACI<br />
Fronsl<br />
Sidc<br />
Unclassiflablc<br />
Others<br />
Frcntrl<br />
Side<br />
Unclusifiable<br />
Others<br />
TOTAL<br />
TOTAL<br />
AIL IMPACTS<br />
Number S<br />
163<br />
rOE<br />
(50.5)<br />
(33.4)<br />
49 (15.2)<br />
3 (0.9)<br />
327 100 fi<br />
144 (55.6)<br />
7L<br />
3E<br />
(?1.4)<br />
(14.7)<br />
6 (?.3)<br />
?59 100 *<br />
of the "centred" type concern lcss than one quarter of<br />
impacts against trees [Table 8].<br />
The E.E.S. distribution shows that the impacts, against<br />
trees especially, arc extremely severe: the E,E.S. was<br />
evaluated at more than 55 km/h for close on three<br />
quflrters of cars impacting a tree, as against 40Va fot<br />
impacts against other fixed obstacles [Table 9].<br />
Table I. Frontal lmpacts-Areas of Overlap of the Car<br />
Front rvith the Obstacle<br />
OVERLAP<br />
v4<br />
v3<br />
l12<br />
zt3<br />
Distrrbuted<br />
Centred<br />
TOTAL<br />
AGAINSTTREES<br />
FATAL CRASHES<br />
ASAINST OTIIER<br />
FIXb:D OBSTACLES<br />
Numbcr % Number %<br />
16<br />
34<br />
50<br />
l9<br />
7<br />
37<br />
163<br />
9.E<br />
?0.9<br />
30.7<br />
11.6<br />
4.3<br />
22.7<br />
100 96<br />
,,a<br />
l9<br />
l8<br />
9<br />
144<br />
r6.0<br />
1? ?<br />
15.3<br />
t2.5<br />
JO.6<br />
b./<br />
100 %<br />
In Side Impact, impacts centred on the passenger<br />
compartment occur in 4OVo of cases, and impacts affecting<br />
all or part of the passenger compartment in more<br />
than 907o of cases [Table l0]. These impacts are extremcly<br />
scverc, as testified by the proportions of cars cut<br />
in two:<br />
I<br />
.r<br />
-J<br />
ii<br />
4<br />
..<br />
i'l<br />
.
lSth lnternetlonel Technlcal <strong>Conf</strong>erence on Experlmental Safety Vehlcles<br />
Table 9. Evaluatlon of E.E.S. (Equlvaleni Energy Speed)<br />
in Frontel lmpact<br />
EQUWALEIiIT<br />
ENERGY SPEED<br />
(kn/h)<br />
ql 35<br />
36-45<br />
46-55<br />
56-65<br />
66-75<br />
>75<br />
SUB-TOTAL<br />
FATAL CRASHES ACAINST:<br />
TREES<br />
2 t.3<br />
11 10<br />
26 t7.2<br />
73 48.3<br />
34 7?.5<br />
151 100 %<br />
Undetermined l2 t2<br />
TOTAL 163 144<br />
OTHER<br />
FIXTD OI]S'].ACLES<br />
15 11.4<br />
32 24.2<br />
33 ?5.0<br />
11 8.3<br />
r3? 100 %<br />
Tabb f 0. Side lmpacts-Areas ol Overlap of the Car Side<br />
with the Obstacle<br />
OVERLAP<br />
Front<br />
Front + Passeng.<br />
Compan.<br />
FaMgcr Compilt. (only)<br />
Passcng- Compilt, + Rff<br />
Ru<br />
Whole cil<br />
TOTAL<br />
AGAINST TREES<br />
FATAL CRASHES<br />
AGAINST OTIIER<br />
FIT'ED OBSTACLES<br />
Number % Number %<br />
6.5<br />
44.5<br />
40 37,0<br />
I 7.4<br />
I 0.9<br />
4 3.7<br />
108 100 %<br />
6 8.4<br />
l8 25.4<br />
30 4?.3<br />
5 7.0<br />
I 1.4<br />
11 15.5<br />
71 100 %<br />
. l87o in impacts against trees;<br />
' 6Vo in impacts against other fixed obstacles.<br />
For those impacts wherc it was possible to evaluate<br />
the E.E.S., this value is grcater than 35 km/h in close on<br />
80Vo of cascs [Table ll].<br />
Table 11. Evaluation of E.E.S. (Equivalent Energy Speed)<br />
ln Slda lmpact<br />
EQI]IVALENT<br />
ENERGY SPEED<br />
(km/h)<br />
*( ?5<br />
?6-35<br />
36-45<br />
46-55<br />
56-65<br />
SUB-TOTAI.<br />
Undetermined<br />
FATAL CI{\SHES AGAINST:<br />
TREFS<br />
3 4.4<br />
11 16.?<br />
72 32.4<br />
21 30.8<br />
11 16.2<br />
68 t}Q /4<br />
40 ctrs<br />
(of which 19 cut in two)<br />
TOTAL l0E 7T<br />
OTHER<br />
FIXED OBS'|ACLES<br />
5 9.6<br />
9 17.3<br />
?5 48,1<br />
11 21.2<br />
? t i<br />
52 100 %<br />
l9 crs<br />
(of which 6 cut in two)<br />
Data Relating to Drivers Involved in Fatal<br />
Crashes against Fixed Obstacles<br />
The driver is alone on board the vehicle in more than<br />
half of the cases (53Vo), and accompanied by a single<br />
passenger in 24Vo of cases.<br />
The age of thc vchicles on board which they are<br />
travelling is less than 3 years in 25Vo of cases, while in<br />
50Vo of cases the cars first came onto the road between<br />
1982 and 1987. Vehicles prior to 1975 represent only<br />
3.5Vo of the cars involved.<br />
The percentage of small sporting vehicles in the<br />
selectcd sample is 10.57o when the obstacle is a tree and<br />
12.47o tor other fixed obstacles.<br />
For drivers (males and females) involved in fatal<br />
crashcs against fixed obstaclcs, those aged under 26<br />
represent almost half of all the drivers of the sample. For<br />
this same age group, the pcrcentage of drivers involved<br />
in bodily injuries occurring in 1990 on the National<br />
Police network reprcsents only 28Vo of cases. lf we<br />
consider only drivers of male gcndcr, the percentagc of<br />
those involved in fatal crashcs against fixed obstacles is<br />
twice as high as the figure for all bodily injuries in 1990<br />
(National Police network). This "over-involvement"<br />
is<br />
even more marked for drivers of malc gender aged undcr<br />
2l: 15.lVo of thc sample as against 6.6% of all Lrodily<br />
injuries [Table 12].<br />
In trilffic, approximately 5Vo of the drivers have had<br />
their driving license for one ycar or less. The drivcrs in<br />
the sarnplc havc had their driving liccnse for less than or<br />
equal to 2 years in 28Vo of cases, and less than or equal<br />
to I year in l87o of cases. 4Vo of the drivers were using<br />
the vehicle without a licensc or had their liccnse<br />
suspended [Tablc l3].
Table 12. Bteakdown (by %) of Gar Drlvsrs by Age and<br />
Gender: 1) In Fetal Crashes Ageinst All Fixed Obstecles<br />
2) In All Accidcnta Involving Bodily InJury<br />
'Nilionil<br />
IATAL ffiHS<br />
FIIEO O0ST^('L6<br />
TOT L<br />
Lt. ^CCiAEmS<br />
IN'URY OCCLIRRINO<br />
TtrAL<br />
toli.. Ncl*ort<br />
13th lntarnetlonal Technlcal <strong>Conf</strong>erence on Experlmentel Satety Vehlcles<br />
against other fixed obstacles. For the unejected fatalities,<br />
the problem for the analyst at the Laboratory is to determine<br />
whether the seat belt (or possibly anothcr restraining<br />
system, such as a child's seat for example) was worn<br />
at the time of the impact. In some cases, by examining<br />
the crash report it is possible to conclude as to whether<br />
or not a restraining systcm was used. In other cases<br />
(chiefly impact$ in which the fatality is the victim of a<br />
critical intrusion), the absence of rcliable information in<br />
the report inevitably results in a significant number of<br />
cases where it is undetermined whether the seat belt was<br />
worn or not.<br />
Table 17. Breakdown of Fatallties by Type of lmpact<br />
Table t8. Fatalities in Frontal lmpact Against<br />
Trees-DsecJiptlon of lmpact Cond itions<br />
5!.D<br />
LEVFI.<br />
t<br />
!<br />
c<br />
c<br />
!<br />
;<br />
2<br />
U{UT@ TATALMF<br />
-1"*<br />
uflHsrx^rNED (nqrlrHnr<br />
EtuM{F<br />
wdN<br />
i<br />
(]i,t sl<br />
In Impact against Trees, evaluation of the delta-V (the<br />
delta-V is equal to the E.E.S., except for cases in which<br />
the fixed obstacle has dissipated a large amount of<br />
energy and cases in which the car swipes the sidc of the<br />
obstacle, in other words when the vehicle comes<br />
completely to a stop at a distancc greater than l0 m<br />
beyond the point of impact without any major change in<br />
its trajectory) was possible for 159 of the 192 fatalities.<br />
The evaluation shows that 887o of the fatalities sustained<br />
il6<br />
^htffiild<br />
ACA|NSTOTItER<br />
FIX!D OBSTACLE<br />
TflAL<br />
IRONTAL SIDE UNCUSSIFIABLE fiHE85<br />
(1e. D<br />
tfl<br />
6.D<br />
f6<br />
{51.J)<br />
rs (33.3)<br />
it<br />
o[,])<br />
?lt<br />
dl,l)<br />
6<br />
{r6.6)<br />
L<br />
15 (1J,0)<br />
(t5.9)<br />
ll 0l<br />
6<br />
(2.0)<br />
r0<br />
tl.t<br />
I<br />
;<br />
I<br />
i<br />
l9l<br />
MAL<br />
(r@ r)<br />
m (rm *)<br />
@t<br />
0m r)<br />
t<br />
I<br />
a delta-V grsater than 50 km/h, and 57% a delta-V<br />
greater<br />
than 60 km/h.<br />
Table 19. Fataliti6e in Frontal lmpac{ Against other Fixed<br />
Obslacles-Description of lmpact Conditions<br />
(N j,i t5tl<br />
6t,D<br />
RE^T.SMT<br />
(fl-[)<br />
4 t-50<br />
5t-m<br />
TO<br />
LBVEL<br />
B<br />
c<br />
i,<br />
!<br />
t snui *,4<br />
28<br />
tlt.t i)<br />
udulctED I^1^LIt]6<br />
!HR6Tf,AINETI<br />
N<br />
t12,7 *t<br />
(20.1 *) {lm *}<br />
By comparison with the results obtained close on ten<br />
years ago by processing fatal motorist crashes occurring<br />
on the national nctwork in the ?nd quarter of 1980 [3],<br />
one observes a sharp increasc in the delta-V, since 687o<br />
of fatalities had sustained a delta-V greater than 50<br />
km/h, and 43o/o a dclta-V greater than 60 km/h. A<br />
delta-V of approximately 58 km/h covcred 50Va of fatalities,<br />
as against 62 kmlh nowadays.<br />
<strong>Int</strong>rusion in the passenger compartment, which is<br />
estimated from photographs of thc car, is quantified as<br />
fl percentage of reduction of the frcc space in front of the<br />
occupant in question. Thrcc degrees of intrusion will be<br />
considered here:<br />
reduclion
speed of impact, is less than that observed in impacts<br />
against trees:<br />
. 52Vo of fatalities sustained a delta-V greater than 50<br />
km/hl<br />
.257o of fatalitie$ sustained a delta-V creater than 60<br />
km/h.<br />
Accordingly, cases of major intrusion are less frequent<br />
and two thirds (l l0/164) of deceases occurred in impacts<br />
in which the reduction of space available for effective<br />
restraining by the seat belt was zero or limited. 28Vo of<br />
fatalities sustained a severe inlrusion (25 fatalitics) or a<br />
critical intrusion (21 fatalities), while the 8 remaining<br />
fatalities (SVo of cases) also sustaincd an inlrusion of lhe<br />
passenger compartment which could not be quantified on<br />
the basis of the data in the files.<br />
Motorist Fatalities ln Slde Impact<br />
The breakdown of fatalities by type$ of obstacles<br />
according to their position in the car in relation to the<br />
impacted zone, the velocity change (delL1l-V) of the car<br />
and the degree of intrusion sustuined by each victim is<br />
given in Tables 20 and 21.<br />
Tabb 20. Fatalities in Slde lmpact Against<br />
Treos-Description of lmpect Conditions<br />
$!vERrtY<br />
(N-7t<br />
tLT<br />
fl!^k.sluE<br />
4r0<br />
J l.{0<br />
2t.s<br />
ltr0<br />
t!s<br />
{ l-m<br />
t0<br />
B<br />
i<br />
A ,: iiflr0ioJ0*l<br />
Jfuffiifkral'r I dEln,.ryrBrrrirhsrEbd.lFr<br />
c _-! cY.lor I<br />
t!tuid udEmid . htruinqFrquil' hnrqqlifish<br />
U!8ffi[D FATALNT{<br />
R6MIN!D ufltalAlNF<br />
I<br />
d t1 D<br />
{17,7 t)<br />
(lr,l t)<br />
,<br />
I<br />
a<br />
I<br />
I<br />
IJ<br />
l0<br />
6<br />
I}<br />
; I<br />
,<br />
I<br />
t7<br />
tr<br />
Sectlon 3: Technlcal $esslons<br />
Trbh 21. Frtalities In Slde lmprct Against Other Flxed<br />
Obetacles-Description of lmpact Conditions<br />
slvG$tt<br />
WITI IFTRUSIOil<br />
I.p<br />
14<br />
mcvr^E$<br />
Its -D<br />
{H-?}<br />
t<br />
!<br />
c<br />
c<br />
t<br />
c<br />
I<br />
I<br />
I<br />
I<br />
OI @.1 *)<br />
UHg4TED F^T^TIS<br />
il<br />
T<br />
t<br />
I<br />
!flDMMH&<br />
1<br />
; I<br />
I<br />
]<br />
p<br />
Gl.r *) tti.9 *,<br />
--' *' " "' b'k<br />
r :::. :-:$i'# i-i::" FFpn<br />
The proportion of ejected occupants among the fatalities<br />
is 22Vo in impacts against trees and 13% in imprtcts<br />
against other fixed obstacles. Apart from the fact that<br />
these ejections generally occur in impacts of high<br />
violence, it should bc spccified that 9 of the 29 cases of<br />
ejection (3l%o) in inrpacts against trees occurred on<br />
board cars which wcre cut in two, and in 2 cases out of<br />
ll (187o) in impacts against othcr fixed obstacles.<br />
As for frontal impact, the lack of reliablc information<br />
in the crash rcport rcsults in a significant number of<br />
"unknowns"<br />
conccrning the use of a restraining system<br />
by uncjected occupants.<br />
In Impact Against Trees, the occupants killed are<br />
near-side occupants who sustirin a dircct intrusion in<br />
58s/o of cascs. For thc far-sidc occupants killed (one third<br />
of ffltalities), it is frequcnt for penetration of the body<br />
side panel to reach or exceed the median planc of thc car<br />
in impacts with a car delta-V grcater than 45 km/h.<br />
A rough evaluation of the car delta-V was ablc to be<br />
pcrformed for 84 of the 130 filtillities, in all vehicle<br />
occupancy configurations. It shows that in more than two<br />
cases out of three, thc impacts occur at a speed grcatcr<br />
than 40 km/h.<br />
In Impact Against Other Fixed Obstacles, the proportion<br />
of near-side fatalities -'with intrusion" and of<br />
far-side ffltalities is of the samc ordcr as in imptct<br />
against trees: -597o andS4Vo of all latalities respectively.<br />
I<br />
I<br />
a<br />
,<br />
t0<br />
a<br />
t<br />
ll7
lSth lnternatlonal Technlcal Gonference on Experlmentel Safely Vehlcles<br />
For cases in which the velocity change of the car was<br />
able to be evaluated (this concerns 53 of the 85<br />
fatalities), one observes that the impacts occur at a speed<br />
greater than 40 km/h in one case out of two.<br />
Motorist Fatalities in "Unclassifiable" Impacts<br />
I l0 occupants (in impact against trees and other fixed<br />
obstacles) were killed in impacts in which the car<br />
impacted the obstacle during an overturning or a rollover.<br />
Since the impacts generally occur on all or part of<br />
the car's roof pancl, it is not possible to estimate the<br />
speeds. However, it is probahle that these impacts occur<br />
at speeds closc to those observed in side impact.<br />
The proportion of fatalities that sustained complete<br />
ejection is l1qo {.J6/l l0), while the proportion of<br />
fatalities which, according to the analysts, used a<br />
restraining system, is 23Vo of all unejected fatalities<br />
(22/e4).<br />
Motorist Fatalities in Other Impacts (Rear Impact,<br />
Side Swipe)<br />
Such cases represent l.4Vo of all fatalities.<br />
Fatalities in Crashes Against Fixed<br />
Obstacles: Prognostic Concerning the<br />
Effectiveness of the Seat Belt<br />
If the seat belt (or an appropriatc restraining system)<br />
had been worn by all dcceased occupants, the proportion<br />
of avoidable fatalities would have been 29o/o for all fatal<br />
impacts against fixcd obstacles and 2lTo for fatal impacts<br />
against trees alonc.<br />
The number of fatalities which would probably be<br />
preventcd, in each impact configuration, has been<br />
calculated taking into account, in particular:<br />
. the violence of the impacts (delta-V);<br />
. the level of intrusion on the occupflnt;<br />
. the age of the occupants.<br />
The evaluations madc by the specialists at the<br />
Laboratory show that approximately 407o of fatalities in<br />
frontal impact (agninst all fixed obstacles) could have<br />
bccn prcvcntcd if the seat belt had been worn in all<br />
positions, as against 160/o in side impact and in impacts<br />
of an "unclassifiable" nature.<br />
In what follows, thc gains which would result from<br />
1007a wearing of the seat belt are evaluated in terms of<br />
the proportion of fatalities prevented, for cach typc of<br />
obstacle and impact.<br />
Prtthahle Effectiveness of the Seat Bell<br />
l. In Frontal Impact: The proportion of prcventable<br />
fatalities in impact against trees would be approximately<br />
32Vo as against 49Vo in impact against other fixed<br />
obstacles. For all impacts against fixed obstacles, the<br />
proportion of fatalitics prevented would be 40Vo [Tables<br />
22 and 231.<br />
Table 22. Proportion Fetelities in Frontel lmpect Using or<br />
Not Uslng a Restrainlng System as per APR<br />
OB.STACLES<br />
OHER<br />
FIXnf)<br />
OBS]N CLtr<br />
TOTAL<br />
YEsT""l-,;;;l*<br />
(15.1)<br />
28<br />
(17.1)<br />
51<br />
(16,0)<br />
(38.0)<br />
103<br />
(62.8)<br />
(19.4)<br />
90 (46,9)<br />
(20. r)<br />
t23 (34,6)<br />
192<br />
(r00 E)<br />
tfl<br />
(r00 E)<br />
156<br />
(lm s)<br />
Table 23. Fatalities in Frontal lmpect: Probable<br />
Eflectiveness ol a Re$training Sy$tem lor Unrestrained<br />
Fetalities and Cases Where Sset-Belt Wearing is<br />
Undetermined<br />
OBSTACLH<br />
TREES<br />
OTIIER<br />
FIED<br />
OBSTACLH<br />
TOTAL<br />
FFEVENTABLE<br />
IIATALITIF,S<br />
62<br />
(38.0)<br />
8l<br />
(5e.6)<br />
t43<br />
(47.8)<br />
REIIAIMN6<br />
FATAI.]mS<br />
93<br />
(57. I )<br />
45<br />
(33,1)<br />
138<br />
(46.2)<br />
UISMWIMD TOTAL<br />
I<br />
(4.9)<br />
r0 Q -31<br />
IE (6,0)<br />
163<br />
(100 E)<br />
000 s)<br />
299<br />
(lm fi)<br />
2. In Side Impatt: In impact against trees, the<br />
proportion of preventable ffltfllities would be approximately<br />
lLVo as against 2l7o in impact against othcr fixed<br />
obstacles. For all types ot impact, this proportion would<br />
be 16% [Tables 24 andz5].<br />
Table 24. Froportlon of Fatalltles In Slde lmpact Uslng or<br />
Not Using a Restraining system as per APR<br />
OESTACLEJ<br />
TREES<br />
O'I'HER<br />
FIXED<br />
OBST^CLTS<br />
TOTAI<br />
(17.1<br />
24<br />
(28.2)<br />
4l<br />
ct t)<br />
ffirutffiG sYsftM usEI)<br />
NO UNDETEroilA"ED TOTAL<br />
(30.2)<br />
4l<br />
(46.2)<br />
(42.8)<br />
56<br />
(43.1)<br />
20<br />
(?3.5)<br />
G5.3)<br />
r30 (lm fi)<br />
(r00 *,<br />
000 16)<br />
Table 25. Fetalities in side lmpect: Probable<br />
Effectiveness of a Re$training System for Unre$trained<br />
Fetalitie$ and Cases Where Seat-Belt Wearing is<br />
Undetermined<br />
OBSTACLES<br />
TREES<br />
OruER<br />
FHED<br />
OBSTACLH<br />
TOTAI.<br />
PREVENTABLE<br />
FATALMLS<br />
l6<br />
(15,0)<br />
IE<br />
34<br />
(?0.2)<br />
REMAINING<br />
FATAT MS5<br />
EO<br />
(74.8)<br />
4l<br />
(67.2)<br />
l?l<br />
(?2.0)<br />
UNbETEhMIMD rOfAj-<br />
II<br />
(10,3)<br />
z (3.3)<br />
r3 (7.7)<br />
107<br />
(100 s)<br />
6I<br />
(lm fi)<br />
r68<br />
(100 %)
3. In Impacts of an 'Ilnclassifiable" Nature; Tlte<br />
proportion of preventable fatalities in impact against<br />
trees would be approximntely 6Eo, as against SlTo in<br />
impact against other fixed obstacles. For all types of<br />
impact, this proportion would be l6Vo [Tables 26 and<br />
271.<br />
Table 26. Proportion of Fatalities In lmpacts of an<br />
"Unclracifiable"<br />
Nature Using or Not Using a Hestrainlng<br />
System aa per AFH<br />
OBSTACLES<br />
F]XED<br />
OBSTAILES<br />
TO'fAL<br />
Tabfs 27. Fatalhles In lrhpacts of an *Unclassifiabte.<br />
Nrture: Probable Eftectiveness of e Restraining System<br />
lor Unrestrained Fatalities and Fatalitise for Which<br />
Seet-Beh Wearing is Undetermlned<br />
OBSTACLH<br />
TREEJ<br />
OGER<br />
FIXED<br />
OBSTACLES<br />
TO.TAL<br />
PREVEMABLE<br />
FAT'\LIIIH<br />
Q,4J<br />
I4<br />
({?,4)<br />
r8 (20.7,<br />
RESTITAIMNG sYsTEM USE<br />
u |<br />
(i6.e)<br />
2 8<br />
(43, l)<br />
,<br />
2<br />
|<br />
r l ?<br />
(?6 1<br />
I<br />
3 1 4<br />
(?0.e) |<br />
o<br />
(44'1)<br />
8<br />
(43.O<br />
EMAIMN6<br />
FAT{MFs<br />
NO IJNDflERTtri\ED TOTAL<br />
48<br />
(88.9)<br />
t? (5r.J)<br />
04.4<br />
(10.0)<br />
G8.9)<br />
(3J.5)<br />
UNDETERMINED TOTAL<br />
?<br />
(i.7)<br />
7<br />
(6.11<br />
(4.O<br />
54<br />
(r00 f,)<br />
(lm fi)<br />
t7<br />
(r00 !t)<br />
4.In Other Impacts: The 10 fatalities in rear impact or<br />
in side swipe werc not restrained occupilnts. The use of<br />
a rcstraining systcm would probably have madc it<br />
possible to prevent the decease of 5 of them, including<br />
I in an impact against a tree.<br />
In sum, out of all fatal impacts against fixed obstacles,<br />
it is probable that approximately 200 of the 69 l motorist<br />
fatalities (29%) would have been preventcd by l007o<br />
wearing of the $eat bclt (or the use of a restraining<br />
system).<br />
The proportion of Iives saved is high (39Vo) in impact<br />
against othcr fixed obstaclcs, where ll7 of the 300<br />
fatalities could have been prevented, and less in impact<br />
against trees, since (only) 83 of the 391 fatalities (Tl%o\<br />
would have benefited from this safety measure.<br />
Applied to the 5014 motorist fatalities which occurred<br />
on the National Police network in 1990, 1007o wcaring<br />
of the seat belt (or thc use of an appropriate restraining<br />
system) for impauts against fixed obstacles only would<br />
probably have made it possible to prevent between 400<br />
and 500 fatalities (185 fataliries againsr rrees and 270<br />
against other fixed obstacles).<br />
65<br />
45<br />
(lm r)<br />
ll0<br />
(100 *)<br />
(r00 r)<br />
$ecfion 3: Techntcal Sessions<br />
Fatalities in Crashes Against Fixed<br />
Obstacles: Prognostic Concerning the<br />
Effectiveness of Road Infrastructure<br />
Improvement by Isolating Trees<br />
While the setting up of a guardrail appears rather<br />
unrealistic lor most impacts against fixed obstaclcs other<br />
than trecs (obstacles which are isolated, or even remote<br />
from the roadway, dwelling houses, etc.), the isolation of<br />
trees can be considered chiefly in the case of repeated<br />
obstacles such as rows of trces planted alongside the<br />
roads.<br />
Concerning the protection of motorists (and trees), we<br />
have considered it "inconceivable"<br />
to $ct up a guardrail<br />
in close on one crash casc out of two.<br />
The same is true is most cases where:<br />
. the setting up of a guardrail is incompatible with the<br />
environment (exits from houscs for example, when<br />
going through small and mcdium-size towns in<br />
particular);<br />
. the tree is isolated:<br />
. the trce is located morc than 4 metrcs from the<br />
roadway (mainly clump type plantations or forests);<br />
. the roadway is very nirrrow (communal lanes).<br />
Where the setting up of a guardrail seemed to us<br />
realistic, we considcred its "probablc cffectiveness,"<br />
taking into account chicfly:<br />
. the impact angle according to the traces of braking<br />
or skidding noted on the roadway and/rlr wheel<br />
marks left on thc road shouldcr and/or, failing that,<br />
the location of impact traces obscrved on the bark of<br />
thc trce;<br />
. the speed of impact (estimate of the Equivalent<br />
Energy Speed) of the car againsl the tree when<br />
evaluation was possible.<br />
The guirrdrail is regarded as effective if, after<br />
absorbing cnergy, it can prcvent impact against thc tree<br />
by guiding the cilr back onto the roadway or contribute<br />
to rcducing the conscquences of the impact.<br />
The isolation of a tree by a flcxible metallic guardrail<br />
implies that a disrilnce equal to the system's pocket of<br />
deformation be available in front of the obslacle.<br />
Accordingly, planlations closest to thc road and the most<br />
dangerous can be protcctcd satisfactorily by a<br />
"conventional"<br />
g uardrail.<br />
Research on ir product which could be used at a small<br />
distrnce from the obstacles and would hc capable of<br />
reslraining the cars in safe conditions (in particular,<br />
prevcnting the car from rebounding at a large angle in<br />
the cvent of impacts) was undertaken several years ago.<br />
By adapling a clcvice designed to rcinforcc the sliding<br />
surface and allow the attlchnrent of a "support" at a<br />
right angle to the tree [Figure l], one can reduce the<br />
distance at which the device is sct up to 0.60 m, or evcn<br />
0.40 m, from the trce. Various impact tests were<br />
ll9<br />
"J<br />
.<br />
li<br />
,<br />
T<br />
.'.<br />
ii
13th <strong>Int</strong>ematlonel Technlcal <strong>Conf</strong>erence on Experlmental Satety Vehlcles<br />
performed on the device set up at the level of the tree;<br />
the results werc good [4].<br />
Figure L SettinE Up a Guardrail: Mounting of Adaptor<br />
When the Obstecle ls Located et a Rlght Angle to the<br />
Support<br />
In the ca$e of plantations lining the road, we have<br />
considered using this 'tspecialized" guardrail in most<br />
cases in which it could be sct up 0.50 m from thc tree.<br />
The gains which would be obtained by realistic setting<br />
up of guardrails along roads lined with trees, clumps of<br />
trees or forests in the open countryside (mainly dcpartmental<br />
roads and national highways) arc evaluated at<br />
SOVI (196/391) in terms of preventable fatalities,<br />
assuming, of course, that the seat belt (or anothcr means<br />
of protection) is worn by each of the fatalities of the<br />
refcrcnce sample [Table 28J.<br />
Table 28. Summary of Probable Effectivenees<br />
(as per APR) of a Guardrail in Fatal lmpacts Against<br />
Flxed Obstaclee<br />
Note that of the 196 fatalities preventable by isolating<br />
trees, wearing of the scat belt (or thc use of a restraining<br />
120<br />
l8 (r r)<br />
t o )<br />
ls (i74<br />
I<br />
8<br />
1.7<br />
rHnrfE(TlvB UNOfrER[iINED MAL<br />
? {?)<br />
J (l)<br />
8 (8)<br />
t- (D<br />
lt 0tt<br />
t,tt<br />
{r 0}<br />
s 6<br />
lE d.2)<br />
rto {91)<br />
ff (ll<br />
l9r {1J3)<br />
rt<br />
system) would have undoubtedly, by itself, made it<br />
possible to prcvent 44 fatalities, or less than one quarter<br />
of these victims.<br />
The isolation of in-line plantations only would<br />
probably have made it possiblc to prevent 457o of the<br />
900 or so fatalities in crashes against trees counted in<br />
1990 on the National Police network, or approximately<br />
400 prevcntable fatalities.<br />
Knowing, moreover, that the proportions of motorist<br />
fatalities in the open countryside in impact against trees<br />
and in rollover (which generally occur aftcr leaving the<br />
roadway) are idcntical (17 to l8% of all fatalities), it is<br />
probable that these mcasures would be beneficial for a<br />
certain number of motorist fatalities in rollovcr. The<br />
effects of this measure arc still of course hard to<br />
calculate.<br />
In thc long term, over 20 years for example, the<br />
widespread setting up of guardrails in "high risk" areas<br />
should make it possiblc to prevent ckrse on 8000<br />
fatalities, or the equivalent of 80% of the fatalities in<br />
France cach year, for all categories of users taken<br />
together.<br />
Conclusions<br />
On the network supervised by thc National Police<br />
(5014 motorist fatalities in 1990), impacts against trees<br />
and othcr fixed obstacles rcpresent 900 and 700 fatalities<br />
respectively.<br />
Fatal crashes against fixed obstacles occur generally:<br />
. outsidc of towns (807o of cases);<br />
. on departrnental roads (587o of cases);<br />
. at night (53Vo of cases).<br />
Plantations lining thc road represent two thirds of fatal<br />
crashes against trees, whilc walls and poles, by<br />
themselvcs, represent more than half of the other fixed<br />
obstacles.<br />
ln 53Vo of cases, the driver is alone on board the car.<br />
The frequcncy of involvernent of drivers ol'male gender<br />
aged 25 or under (41ok) is twicc that observed for all<br />
bodily injuries. The proportion of drivers who have had<br />
thcir driving license for I ycar (at most) and of those<br />
driving without a license is 22o/o. Almost half (467o) of<br />
the drivcrs on whom the alcohol tcst was performed and<br />
the results were known, had an alcohol level excccding<br />
the legal rate.<br />
For all fixed obstacles combined, frontal impact is the<br />
cause of the highest percentage of occupant fatalities<br />
(52Vo), beforc side irnpacts (3lok) and impacts of an<br />
"unclassifiable"<br />
nature in which the car impacted the<br />
obstacle during an overturning or a rollover (160/o).<br />
In frontal impact against trecs, more than half of the<br />
fatalities (restrained and unrestrained occupants) for<br />
which the violence of impact was able to he estimated<br />
sustained a delkr-V greatcr than 60 km/h, which<br />
obviously resulted in extensive intrusion ofthc passenger<br />
compartment. Fron(al inlpacts against other fixed
obstacles are, in general, of lower violence, since a<br />
quarter of fatalities are involved in impacts of severity<br />
greater than 60 km/h delta-V.<br />
Side impacts against fixed obstacles are extrcmely<br />
severe: the car delta-V is estimated at more than 40 km/h<br />
in more than 50% of case.s where it was able to be<br />
evaluated, and close on one car out of five in impact<br />
against trees is cut in two. In side impact against trees or<br />
other fixed obstacles, the fatalities ars near-side<br />
occupanls and they suslain a direct intrusion by the<br />
obstacle in close on 60Vo of cases. One third of fatalities<br />
are far-side occupants and these fatalities frequently<br />
occur in impacts in which the penetration of the car<br />
reaches or exceeds the cenlreline.<br />
With l570 of fatalities, impacts of an "unclassifiable"<br />
nature are far from insignificant.<br />
1007o wearing of the $eat belt (or the use of another<br />
means of protection) would probably have made it<br />
possible to prevent 29Vo of fatalities against fixed<br />
obstacles (Zl%o in impact against trees). It is in frontal<br />
impact that thc pcrcentage of preventable fatalities seems<br />
greatest: 49% in impact against other fixed obstacles,<br />
32Vo in impact against lrees.<br />
Over one year, the cffccts of this safety measure,<br />
applied in full, would havc made it possihle to prevent<br />
between 400 and 500 fatalities, including approximately<br />
200 in impacts against trees.<br />
st-w't6<br />
Patterns and Causes of Serious Injury<br />
Peter L Harms<br />
Private Consultant<br />
R J Tunbridge<br />
Transport and Road Research Laboratory<br />
Abstract<br />
This Paper reports on a sample of nearly 3700<br />
accident-involved cars with 4491 injured occupanrs.<br />
These were selected from a comprehensive crash-injury<br />
investigation which has been underway in the UK since<br />
1983. Detailed injury mechanisms quantify injury<br />
sources from this very large sample and enablcs a<br />
perspective view to be taken on future direction of<br />
remedial measures. The results show that the majority of<br />
impacts were to the front of the vehiclc and involved the<br />
offside part of the front more often than the nearsidc.<br />
Approximately three quarter$ of the front occupant$ were<br />
known to be restrained, while most of the rear seat<br />
passengers were unrestrained. As expcctcd, thc unrcstriiined<br />
passcngcr sustained a greater level of overall<br />
injury than the restrained, this difference being more<br />
pronounced in side impacts. ln absolute numbers, most<br />
injuries occurred to the cranium and limbs with the<br />
steering wheel being responsible for most head/face and<br />
trunk injuries to the driver. Most of the other injuries to<br />
:<br />
Sectlon 3: Technlcal Sessions<br />
The gains which would result from realistic setting up<br />
of guardrails along departmental roads and national<br />
highways lincd with trees are evaluated at 457o of all<br />
fatalities in crashes against trees, or approximately 400<br />
preventable fatalities over one year.<br />
Acknowledgements<br />
We should like to thank the Police Forces for kindly<br />
providing us with a copy of fatal crash police reports.<br />
Without their cooperation, this study would have been<br />
impossible.<br />
References<br />
l. Cendarmerie Nationale (National Police), 1990:<br />
annual road accident statistics.<br />
2. Fatal Accident Reporting Systcm, 1989: A review of<br />
information on Fatal Traffic Crashes in the United<br />
Slates.<br />
3. J.Y. Foret-Bruno, F. Hartemann et al.; "hincipales<br />
caracteristiques des accidents mortels de voitures<br />
particulicrcs survenus en FRANCE au cours du 2eme<br />
trimestre de 1980." Unpublished Report of the<br />
Laboratory of Physiology and Biomechanics associatcd<br />
with PEUGEOT SA/RENAULT<br />
4. General Review of Roads and Aerodromes (January<br />
1984):<br />
--Quels<br />
dispositifs de retenue pour demain"-<br />
J.C. Dupuis, French Road Satety and Tratfic Board.<br />
Amongst Car Occupants<br />
all occupants occurred when they contactcd adjaccnt,<br />
internal structures in the dircction of impact. The seat<br />
belt webbing featured highly in trunk injuries and<br />
although thesc are seen as a lesser evil than injuries<br />
sustained by the unrcstraincd. A proportion of upper<br />
body injuries were caused by contact with another<br />
vehicle or external structure and it is reasoned that<br />
attcntion should bc given to reducing injuries from<br />
intrusion in side irnpacts. The results indicate that all<br />
occupants should be restrainerl. Means such as persuasion<br />
or enforcemcnt should bc uscd to make restraint use<br />
effective. Considcration must also be given reducing<br />
entrapment, pilrlicularly of the lower limbs, in ordcr to<br />
improve the clinical outcome of casualties who may have<br />
other injurics.<br />
<strong>Int</strong>roduction<br />
Analyses presented in this Paper derivc from an ongoing<br />
study fiom which new information is addcd to the<br />
main ccmputcriscd database on a regular basis. The<br />
present work on car accident injury mcchanisms, known<br />
as the Cooperativc Crash Injury Study (CCIS),<br />
commenced in 1983 and this Papcr uses data gathered<br />
from that time up to mid-1989. Thc study mcthodology<br />
has previously been described by Mackay ct al [],<br />
Otubushin and Galer [2], and with database aspects more<br />
12l<br />
i{<br />
;t<br />
:i<br />
l!i<br />
;<br />
d<br />
fi i<br />
-;
13ffi lnternetlonel Technlcal <strong>Conf</strong>erence on Experlmental Satety Vehicles<br />
recently being described by Renouf [3]. The data is<br />
subject to a number of validation checks and the full<br />
data "released" for analyses only when these are<br />
satisfactory. Therefore the database operates on a process<br />
of continuous growth. Each release will contain more<br />
data than its predecessor, a large database being required<br />
to analyse certain variables that are not vcry common.<br />
The new data will of course be gathered during the time<br />
that vehicle designs are changing. As the database grows<br />
in size, more refined and detailed analyscs can take<br />
place. This could include comparisons between model<br />
types in the same impact configuration. The effects of<br />
relevant legislative changes such as the new rear seatbelt<br />
law will hopefully bc investigated in future presentations.<br />
However there is always the danger that vehicle<br />
design changes and the introduction of new legislation<br />
will ma-ke some aspects of the earlier data obsolete. Time<br />
series analyses mu$t be treated with some caution as<br />
changes over an extended period will mean that a<br />
particular analysis may not always be comparing "like<br />
with like."<br />
Given some restrictions on observing and therefore<br />
assigning injury causes in modern vehicles, probable<br />
contacts are considered, relying on the expertise and<br />
experience of the investigators. A high standard of<br />
investigation and audit is required. The Papcr attempts to<br />
address thc qucstion of where problem areas lie in<br />
relation to injury causation.<br />
Cars that are less than 6 years old at the time of the<br />
accident and have been damagcd sufficiently to be towed<br />
from the scene form the basis of selection for investigation.<br />
Thcsc are known as "case" vehiclcs for the<br />
purposes of the study. The sample is further stratified by<br />
injury severity (as assessed by the police), based on the<br />
highest injury level in the selccted vchiclc. Thc towaway<br />
criteria is not applied when there is a fatality in the<br />
"casc"<br />
vchicle. Thcrefore the accidents arc sampled on<br />
vehicle age, damage, police injury sevcrity and injury<br />
outcome. This sampling basis has relevance when<br />
weighting the data in order to relate sample size and<br />
certain parameters to the number of car accidents in a<br />
given catchment area and eventually to thc nfltional<br />
accident $cene. Application of weighting factors to the<br />
database is in hand but will not be applied in this Paper.<br />
The sample used in the following analyses initially<br />
comprised 3695 vehiclcs and 6220 occupflnts of which<br />
4491 were injured. Injury severity was assessed using the<br />
1985 Abbreviated Injury Scalc [4]. Thc parameters<br />
considered were occupant age, injury severity/body<br />
region, seating position, impact dircction, restraint use<br />
and injury mechanisms.<br />
Impact Characteristics and Restrnint Use<br />
Impact C harac t e ri sti c s<br />
A vehicle can have more than one impact in an<br />
accident and the data set records up to thrcc in severity<br />
order. Only the direction of the most severe impnct is<br />
122<br />
considered in these analyses, using the Collision<br />
Dcformity Classification (CDC) system t5] which<br />
allocates direction of impact using the twelve clock<br />
points. There arc further gradations in this system related<br />
to the side and part of the side impacted, height and also<br />
extent of the impact zone and some of thesc will be<br />
considered. Accidents involving a right-angled impact<br />
plus or minus one clock point related to the struck "side"<br />
of the vehicle have been chosen. Therefore a frontal<br />
impact is I I, 12 or I o'clock to the vehicle's front<br />
structure. Similarly an offside impact is 2, 3, or 4<br />
o'clock to the right-hand sidc and 8, 9 and l0 o'clock to<br />
the left-hand side of the "case" vehicle. It is appreciated<br />
that vehicle collisions are rarely straightforward as there<br />
is often an elcmcnt of rcbound and/or spin following the<br />
initial impact which could affect occupflnt contact and<br />
possibly injury outcome. However, the simplificd<br />
approach described above enables most of the relevant<br />
accidents to be categorised. The sample size using the<br />
above classification is given in Table I wherc il will be<br />
seen that the majority of impacts were frontal.<br />
Table 1. Prlnclpal Dlrectlon of lmpact<br />
N.<br />
(t)<br />
Frontdl NeorElde olfslde Redr A1l othe16t TO/IAt<br />
21f1 f01 341 ?0{ 112<br />
(57.7) (8.il (9.{) (5.5} (19.3)<br />
3 695<br />
(100)<br />
(* Includes cwlpes, rol lovers, sohe mult-Iple lmgracl5 qn6 mclassified)<br />
The CDC system indicates the location of principal<br />
impact to the exlcrior o[ the relevant vehicle body side,<br />
dividing the front into thirds and the side according to<br />
the main components. The latter are the engincTbonnet<br />
(front), the passcnger compartmcnL and the luggage area<br />
(back). Thc impact distribution using these categories is<br />
shown in Tables 2 and 3.<br />
Table 2. Vehlcle Body Location of Principal lmpests,<br />
Frontel Collisions<br />
Eady Rqlal Lt{ 1/3 CsDtrs 1/l RH 1/3 LH+Csntr€ H+Centre tu11 Wldtt<br />
N.<br />
ir)<br />
291 95 ddo 228 )83 69{<br />
(13.7) (d-st (?0-6J ll0.?) (18,0) {32,5)<br />
Table 3. Vehicle Body Location of Principal lmpacts,<br />
Side Gollislons<br />
hdv Reqlo Front pass Corc hck Fasc+FronE Pac!+Back Nll LcnEtt<br />
Nssr*Lds<br />
(r)<br />
off*tdc ..........r<br />
(t).<br />
.._ Co#ined<br />
It)<br />
11 89 10 18 f5 ll<br />
(?5.6) 129.6) (3.31 tt5.9t trt) (1.7t<br />
88 lld 7 8'l 29 e2<br />
(?s-4t t3?-9t (e-0 t25.U (8.4) (6.3)<br />
165 2Ol L7 165 65 33<br />
I25,rt tlr.l, (2.6t {2s.{l (10-0) t5.11<br />
Taking all impacts to the front, it will be seen that<br />
thcrc is a bias towards the offside of the vehicle. In side<br />
impacts, the majority (72Vo) involved the passenger compartment,<br />
eithcr cxclusively or in combination with other<br />
parts of the vchicle.
Restraint Use and Occupant Age<br />
Four classifications of restraint u$e itre considered in<br />
the study. When there is clear visual/mcchanical cvidence<br />
on the rcstraint itsclf and/or clinical evidence such<br />
as body contusions and, in some ca$es, rib or pelvic<br />
fractures along the line of the belt webbing, the restraint<br />
is<br />
'-Used."<br />
considered In addition, unless it is iudged that<br />
there is likely to be personal sensitivity in relation to<br />
scvere or fatal injuries, questionnaires arc sent to every<br />
adult occupant in the case vehicle requesting, amongst<br />
other information, whether a restraint was worn at the<br />
time of the accident. If the answer is in the affirmative<br />
but there is no clear visual and/or clinical evidence to<br />
the conlrary, this category is classified as "Used-<br />
Unproven." In some cases there is positive cvidence that<br />
the restraint was not used which forms the third<br />
category. The final category of "Use Not Known"<br />
indicates there is no clear evidence either way and no<br />
questionnaire respon$es have bcen received - despite<br />
reminders. Restraint use for thc sample rclated to seating<br />
positions for all impact directions is given in Table 4-<br />
Table 4. Hastrelnt Use Felatlve to $eaiing Posllion<br />
R€aEr{lnt UE€<br />
seat Porltlan<br />
Driver6 ll.<br />
" (r)<br />
FS PaaEenqerE N,<br />
' {r)<br />
RS Pa88orlgera N.<br />
' 1r)<br />
s..ttng Poa HK N,<br />
Used FIus Ndt UEod Use Nfi<br />
Uaed-Unprov€n<br />
2769 249 66'7<br />
(?5) (7) (18)<br />
110{ 89 210<br />
(78) (61 (16)<br />
E7 993 2e<br />
ts) {9}) tl)<br />
7 21 11<br />
TOTAL<br />
3585<br />
{r00)<br />
r{ 21<br />
(100)<br />
107 9<br />
1100)<br />
1\)TAL 3931 1J52 97'7 6220<br />
It should be noted that the restraint-use situation for<br />
the totd, sample since the study commenced in 1983 is<br />
shown and indicates a very low wearing rate for rear seat<br />
occupants. Since Aprit 1988 all new vehicles are obliged<br />
by law to have rear restrilints fitted but some vehicles<br />
had them fitted before that date, inctuding child<br />
restraints. Durirrg the period covered by this analysis,<br />
legislation was enacted covering compulsory belt<br />
wearing for rear seat child occupants and an analysis nf<br />
the 1988 data shows a marginal improvement in wearing<br />
rate for this category of occupant. Restraint usc related<br />
to age for all seating positions is given in Tablc 5.<br />
It will be noted that the highest percentagc in the "Not<br />
Used" category relate to the young and elderly.<br />
Tablr 5. Age Hehted to Restlalnt Ure (Pcrcentegs per Age Band)<br />
Age /<br />
RestrainE Use<br />
Used plus<br />
Used-Unproven<br />
Nof, Used<br />
Use NK<br />
11<br />
$ectlon 3: Technlcal $essions<br />
Legislation enacted in the UK in Sept 1989 requires that<br />
childrcn under 14 years of age are restrained when<br />
seatecl in thc rear and when belts are availablc' This law<br />
has recently been extendcd to adults and it is hoped that<br />
thc full legislation will have a positive effect in reducing<br />
the number of rear seat casualties.<br />
General Injury Distribution<br />
Injury Patterns and Comparisons<br />
Casualties can be compared on a restraint-use basis for<br />
different seating positions using the Miiximum AIS<br />
(MAIS) as an injury severity indicator (Table 6)' Where<br />
restrained occupants are considcrcd in the analyses, The<br />
USED and USED-UNPROVEN categories have been<br />
cornbined and the NOT KNOWN category discounted as<br />
it is reasoned that this approach would givc an<br />
acceptable representation of the situation. It must be<br />
accepted that the sample seleclion is biassed towards<br />
serious and fatal injuries which is bound to rcduce any<br />
diflerences bctween restrained and unrestrained occupflnrs.<br />
Table 6. <strong>Int</strong>ury Comparlsons-All lmpact DirecllonE<br />
ReEtraint Use/<br />
Setting Position<br />
Restrained Drivers<br />
Unres t rai hed<br />
Rario Unrestrt/Restrt<br />
R€stratned FSPS<br />
Unr€strdined FSPS<br />
Rario Unrestrt/Restrl<br />
Restrained RsPs<br />
Unre6trrined RSPs<br />
Rrtio Unr€strd/Festrt<br />
TOTAL<br />
MAI.5 2-6<br />
N. (U<br />
91? (4r)<br />
118 (6r)<br />
I.4:l<br />
382 (16)<br />
46 (66)<br />
I.s:l<br />
44 (14)<br />
2s2 (rt)<br />
2.4:I<br />
urs l-6<br />
N. (t)<br />
377 (r8)<br />
55 (28)<br />
t'6:I<br />
156 (1s)<br />
24 (14)<br />
11 (3)<br />
9? (12)<br />
'l ,0rI<br />
uI5<br />
N.<br />
-6<br />
t)<br />
211? {r00)<br />
19{ ( 1001<br />
10{ s<br />
70<br />
306<br />
4 491<br />
(100)<br />
(100)<br />
( 100)<br />
( r00)<br />
The effect of rcstraint use on overall injury severity<br />
can be seen in all groups, particularly amongst the higher<br />
levels (MAIS 3-6) and also with the rear seat passengers'<br />
However the ratio is less pronounccd amongst drivers<br />
and this is worth exploring further for all seflting<br />
positions in relation to impact direction (Table 7)'<br />
For purposcs of definition, a driver in an offside<br />
impact and a front seat passcnger in a nearside impact<br />
are considered as having been on the "struck side." The<br />
data shows that there is also an increase in injuries<br />
sustained by restrained FSOs in struck-side impacts<br />
compared to frontal impacts; 1.3:l (53142) for drivers<br />
and 1.2:l (42/35) for passengers. There is also a<br />
0-45_910-r17-2425-3435-4445_5455-5960_6455-6910-74GE75NK TOTAL<br />
26 19<br />
70 77<br />
4 4<br />
JI<br />
63<br />
6<br />
26<br />
12<br />
70<br />
18<br />
L2<br />
11<br />
tl<br />
13<br />
'14<br />
13<br />
l4<br />
13<br />
't5<br />
14<br />
LZ<br />
14<br />
15<br />
10<br />
19<br />
1 E<br />
67 41<br />
25 19<br />
I 34<br />
TOTAI, (N) 105 95 Zrs 1495 1166 809 s59 280 235 13s 83 110 933 t6?z0l<br />
taq11l<br />
taJfll<br />
123
lilth lnternatlonal Technlcal Conlerence on Experlmentel Satety vehlcles<br />
comparative increase of 1.7:l (47127) between frontal<br />
and nearside impact-related injuries for unrcstrained<br />
RSPs.<br />
Tabh 7. AIS 2-6Inlurles relative to Seating Posltlon<br />
and lmpact Direction<br />
ImF{ct<br />
Direction<br />
Frontal<br />
(t) of sub<br />
NearE ide<br />
(+) of 6ub<br />
Offeide<br />
(t) of sub<br />
(Excludtnq surface injurieE but showlnq<br />
(1) af ToTAL injuriee per sub-set)<br />
Bet<br />
sat<br />
s€t<br />
ReBt ra in€d<br />
Drivsrs FS PaEE DriverE<br />
526 206<br />
(42) (35)<br />
84 57*<br />
(d3) (42)<br />
114 * 23<br />
(s3) (26)<br />
UIr€strai ned<br />
FS Pass Rs Pa66<br />
6S 2'7 120<br />
(51) (61) l27l<br />
9 5* 42<br />
(r) (*l (4?)<br />
1?* - 23<br />
(*) - (31)<br />
(*) Nwb+re tdo Iry to expre6s 8s percentaEeE<br />
(*) Indicatee caEualty sitting on struck eide (8.€ tcxt)<br />
If the more serious injuries of MAIS 3-6 are<br />
considered, the ratios become I .2: I (50/a I ) for restrained<br />
drivers and 1.7:l (69/40) for front passenger$ (Table 8).<br />
Table 8. MAIS Comparieon for Dlfferent lmpact Directione<br />
Di xect ion<br />
FronLal<br />
Off$ide<br />
Nearside<br />
percentages for severe hjuries (MAIS 3-6)<br />
Restrained<br />
Drivers FSP$<br />
4I<br />
50<br />
50<br />
40<br />
69<br />
Unres traifled<br />
DTiveTs FSPS RSPS<br />
68 44 51<br />
- 38<br />
Using the five AIS body regions, the distribution of<br />
serious injuries AIS 2-6 (excluding external) rclated to<br />
$eating position, restraint use and impact direction is<br />
given in Table 9.<br />
Table S. Distribution by Body Fegion of Casualties<br />
with AIS 2{ Inlurles<br />
Bady Rqlon/<br />
ScaE Fos<br />
(Releted to lrcact Dtr€ctlon and excludlng $rfscc InjurteBl<br />
FronErI<br />
lEtlr DWs<br />
uuestr. mE<br />
Resrr. FSPS<br />
Ur€str, FSP5<br />
UffEEtT. RSFS<br />
Ne$slds<br />
ltE!?l- DVRS<br />
Utr€tT, DVFS<br />
Re$Er - FsPs<br />
UEeaET, FSFS<br />
uEeEtr, RSFS<br />
offEldc<br />
tEl?f ms<br />
utrertr, tffRS<br />
R€str, FSpS<br />
Unrostr. FgPS<br />
Unrestr. RSPS<br />
The data shows that head and limb injurics<br />
predominate and this will be explored in suhscquent<br />
Scctions. Suffice to say at this stage that many of the<br />
hcad injuries were relatively brief periods of<br />
unconsciousness and a distribution of limb injuries<br />
sometimes shows relatively smaller numbers pcr<br />
individual limb region. Many casualties sustained more<br />
than one injury (Table l0).<br />
tu<br />
Head/ Face chesE/ Abdo/<br />
Heck uF &ck h Bick<br />
252 8$ 199 5A<br />
27<br />
't6<br />
12<br />
r0<br />
12<br />
a<br />
23<br />
86<br />
5<br />
r{<br />
3r<br />
I<br />
5{ 19 21 20<br />
5 1 6 2 7 3 1<br />
e 2 4 2<br />
2 9 3 3 2 1 9<br />
2 ? r ?<br />
2 6 4 7 3<br />
s e 8 4 5 3 2<br />
1 3 - r l 8<br />
1 3 7 7 2<br />
ri ; ; ;<br />
Pslvl s/<br />
LlId9<br />
280<br />
41<br />
107<br />
68<br />
32<br />
I<br />
2<br />
2a<br />
6l<br />
IJ<br />
rl<br />
Crsua It lei<br />
per Group<br />
205<br />
21<br />
l?o<br />
TOTAL<br />
638 159 480 228<br />
(tl ({81 (rz) (35) (r?) {s<br />
I loo)<br />
8a<br />
9<br />
s7<br />
5<br />
4Z<br />
25<br />
,i<br />
Table 10. AIS 2-6 Infuries/Occupent Group Helative to<br />
lmpact Direction<br />
hlEct bir, /<br />
InJury Graupe<br />
tsronta 1<br />
Ufi€-fnfurv<br />
fro Injuriee<br />
>2 lnJurieF<br />
Festra i ned<br />
Drlvers FS Fass<br />
N, (t) N. {r<br />
I 02 { 57 ) r2'l t62<br />
rl4 125) 59 t29<br />
90 (:t?) ?0 (10<br />
Unrestrained<br />
Drlverg t's Pnga RS pass<br />
N- {t<br />
{0 (58<br />
1l (r9<br />
15 (??<br />
N, (T<br />
15 (56<br />
t1 i41<br />
1 (4<br />
N<br />
11<br />
18<br />
(t<br />
64<br />
?1<br />
sanple slze 526 (1oo) 206 (100 68 (100) 27 (100) l?o {100)<br />
N+ars ide<br />
one lnlury<br />
ruo trljurles<br />
>2 Injuries<br />
14<br />
11<br />
63'<br />
1?)<br />
20)<br />
z1 (44<br />
15 (26<br />
t9 (3.1<br />
l<br />
4<br />
i*)<br />
2 - 2 4<br />
I - I t<br />
2 14<br />
SilFIe elEe 84 {100} 5? {100t 9 5 00<br />
offslde<br />
tlFFlurv<br />
fro InJurie8<br />
>2 InJurles<br />
61 (s4<br />
I<br />
23(20)<br />
l0(261<br />
16 (64<br />
1 tzA<br />
2 (8<br />
srll}le slzB 1r4 (100) 27 (roo) L7 23<br />
(r) NMbera too smrl for meanlnqrur percentaEres<br />
These figures show relatively more multiple injuries<br />
in side impacts than in frontal. This is discussed furlher<br />
in the next <strong>Section</strong>.<br />
Overall Injury Severity retatert ro Impact Direction<br />
Based on the restraint-use information given in Table<br />
2, and considcring only injuries in thc AIS 2-6 range,<br />
analyses will be prcscnted by seating position and<br />
principal impact dircction for restrained drivers and front<br />
seat pilssengcrs. Unrestrained front scat occupants will<br />
also be considered whcrc appropriatc and, since thcy<br />
predominale within thcir group, data on unrestrrtincd rear<br />
seilt passengers will also bc presented. Impact<br />
configurations, seat occupancy or restraint-use data not<br />
producing sufficienlly large numbers for any meaningful<br />
analyses will not be reported.<br />
Tables I l, 12 and 13 show the maximum injury distribution<br />
for diffcrent seating positions and principal<br />
impact directions. The Not Known category has not been<br />
reported.<br />
Table 11. MAIS 2-E Distribution, Injured Occupants in<br />
Frontal lmpacts<br />
Injury<br />
Severi ty<br />
MA]<br />
MA]<br />
l,lA. 5 4<br />
MA:<br />
MA] s 6<br />
TOTAI<br />
ot wlrich-<br />
FataI<br />
FeEtrai ned<br />
Drivers FS Pasa<br />
N. (r) N. (1)<br />
308<br />
117<br />
]I<br />
4l<br />
I25<br />
49<br />
c<br />
I<br />
(61<br />
124<br />
(4<br />
{8<br />
5<br />
4<br />
I<br />
IO<br />
Unres t rained<br />
Drivers FS FiFE RS Pass<br />
N. (r) N. (S) N. (r)<br />
3Z<br />
I4<br />
I<br />
,l<br />
'l<br />
2<br />
ls (s6<br />
7<br />
I<br />
2<br />
z<br />
126<br />
(4<br />
l'l<br />
t 7<br />
69 i.53<br />
34 t26<br />
6 (s<br />
16 (t2<br />
6 (s<br />
526(r00) 206(100 68 00 27 (100) 1lr (r00<br />
81 (15) 27 (r3) (24) 5 t19) (16)<br />
Tabl6 12. MAIS 2-6 Distribution, Injured Occupants in<br />
Nearslde lmpacts<br />
I rrl ury<br />
Seve}- i t y<br />
MAIS ?<br />
MAIS 3<br />
MAIS 4<br />
MAIS 5<br />
MAIS 6<br />
TC}TAL<br />
or wnrcn<br />
faf.il<br />
ReELra ined<br />
Drivr:js FS FaFs<br />
N. (+) N. (r)<br />
42<br />
I<br />
I2<br />
7<br />
0<br />
I<br />
0<br />
4<br />
I<br />
22<br />
1l<br />
IO<br />
4<br />
10<br />
rtq<br />
(1e<br />
(18<br />
('7<br />
(ltJ<br />
Unrestra irred<br />
Llrivr'rs FS Pars lll; Pass<br />
N. (*) N. (*) N. {s)<br />
4 t<br />
1 1<br />
I 1<br />
a 1<br />
1 l<br />
26 /'62<br />
10 (24<br />
3 (?<br />
2 \ s<br />
1 (2<br />
84(100) E?(100) 9 5 42(100)<br />
18 l2 18 t32 ) 4 J 5 (12)<br />
* Numbers too small for meaningful percentages
Tebh 13. tlAl$ 2.6 Dletrlbutlon, Infured Occupent$ In<br />
Offside lmpactr<br />
Injury<br />
Severi fy<br />
MAIS<br />
MATS I<br />
I.IAIS 4<br />
}'AIS 5<br />
MAIS<br />
TOTAI,<br />
of whlch-<br />
FataI<br />
Rest reined<br />
Drivera FS Pass<br />
N. (r) N. (r)<br />
54<br />
33<br />
9<br />
u<br />
9<br />
(48) 15 (60)<br />
(2e) 6 (24)<br />
(8)<br />
(7) 3 (12)<br />
(8) 1 t4)<br />
Unrestrained<br />
UTIVETS K5 FASS<br />
N, (*) N. (t)<br />
4 L 2<br />
4 4<br />
2 Z<br />
2 4<br />
5 1<br />
114 (1oo) 25 (1oo) 1 q 23<br />
18 (16) 4 (16) I<br />
* Nu.mbers Eoo smalI for meaningfuL percenLage$<br />
Although not tabulated, on average, half ,n. inlurir*<br />
sustained in all impact directions were of MAIS I<br />
severity.<br />
It is wcll cstablished that injury outcome is largely<br />
speed dcpendent; detailed analyses have not been considered<br />
in this Paper but will doubtless be presented in<br />
future. The key variable of velocity change on impact<br />
(Delta-v) is computed from detaitcd crush measurements<br />
from the case vehicle and known constants. There are<br />
some invalidating conditions attached to this method and<br />
thcrefore Delta-v figures cirnnot always be produced.<br />
However some were available for thc accident sample<br />
analysed although it will be appreciatcd that sample size<br />
diminishes with increasing impact speed. Table l4 shows<br />
thc variation of mean Delta-v related to Maximum lnjury<br />
Severity for restrained front occupants in frontal<br />
collisions.<br />
Table 14. Verietion ol Maxlmum Inlury Severlty wlth<br />
liean Delta-v<br />
DriverB<br />
Sanple size<br />
Mean Dv kmlh<br />
F,S. PasB. -<br />
salnpre srze<br />
Mean DV kft/h<br />
Restralned FSOE in FronEaI fmpacfs<br />
MAIS 2 f 4 5 6<br />
L37 55 L7 10 7<br />
42.2 48.6 57,4 56.1 58.3<br />
4 1 2 L 5 8<br />
38.6 44,8 53,2 66,1<br />
The scale of injury severity increases with mean<br />
Delta-v. This is more pronounced for front seat<br />
passengers than for drivers, although accident sampling<br />
and missing Delta-v values in the data set may influence<br />
trends.<br />
Injuries and Probable Causes<br />
Several points must be borne in mind when ascribing<br />
contact zones giving rise to injuries: Injuries and<br />
mcchanisms are not mutually exclusive ie, there can be<br />
morc than one injury from a single source and also<br />
several sources can be responsible for one initial injury<br />
with the possibility of also aggravaling that injury.<br />
Alternative source$ can also be responsible and an earlier<br />
method of coding used in the study did not enable all<br />
possibilities to be taken into account. Some injuries arise<br />
<strong>Section</strong> 3: Technlcat Sessions<br />
from direct blows and others can be induced from<br />
contact with another body region. Non-contact, decelera- i:<br />
tion type injuries are also a possibility. Rebound injuries l:<br />
also occur, paflicularly with restrained occupants in side<br />
'*<br />
_<br />
impacts. There is sometimes a degree of unccrtainty in<br />
assigning injury cause$ so probability must be<br />
considered. With thesc limitations in mind, principal<br />
''<br />
causes of injury have been used in the analyses and will<br />
be presented by impact direction, seating position,<br />
restraint use and AIS body region. Restrained and<br />
unrestraincd occupants injury details will bc compared i<br />
where appropriate. n<br />
-<br />
Frontal Impacts<br />
Drivers<br />
There were 526 restrained and 68 unrestrained drivers :<br />
involved in frontal impacts with injuries AIS 2-6. These<br />
figures will bc used in subsequent analyses and presented<br />
for different body regions. For ease of presentation, the "<br />
bony pelvis has been included with lower limbs.<br />
;<br />
Limb Injuries (ltttluding Bony Pelvis). As mentioned I<br />
earlier 3.2 and indicated in Table 9, limb injuries ;i<br />
predominatc. For the restrained drivers, 280 casualtics "<br />
(537o) had limb injuries of AIS 2 or 3 with one AIS 4<br />
+<br />
(pclvic crush). However the picture is more complex in r<br />
that these injuries were to different limbs and linb<br />
regions throughout the sub-set, thcrc bcing 521 r<br />
individual limb injurics amongst the 280 casualties with<br />
such injuries. They were frequently concomitant with i:<br />
serious injuries to other body regions in the samc driver :<br />
casualtv. J<br />
For unrestrained drivers, there were 4l (607o) with<br />
limb injuries. Of these there was a toml of 72 scparatc<br />
injuries to different limb regions and the same remarks<br />
apply as for the restrained sub-set. The injury distrihution<br />
for both groups is given in Tablc l5 and a further<br />
distribution by limb rcgion in Table 16.<br />
Table 15. Drivers in Frontal impacts<br />
AIS 2-5 Injury Distribution,<br />
Limb and Pelvic Iniuries<br />
AIS Restrained Unrestrained<br />
z<br />
3<br />
4<br />
15e (s?B) 21 (slr)<br />
120 (43+) 20 (4e+)<br />
r (
lSth lnternetlonel Technlcal <strong>Conf</strong>erence on Exparlmentel Safety Vehlcles<br />
Table 16. Drlvers in Frontal lmpacte<br />
R€6t rtr Ined<br />
IFTTSniF<br />
Eight side<br />
Dlstribution oi ArS e-6 Lidr Injurier by tlr$ R.glqn<br />
Fclvisr Hip Thlgh l(n€e b/l€q Foot Should Am Ttr<br />
(zil<br />
' r 8 1 5 2 8 3 8 1 3 5 5<br />
t64<br />
(2{)<br />
27 5C 20 31 73 35 89 ]33<br />
MAL 28 65 llt d8 1dd 52t<br />
Unrcatra ined<br />
EETTTII_<br />
Right Stde<br />
(2)<br />
5 5 7 2 1<br />
3 9 1 e 5<br />
5 2<br />
I 13<br />
TdTL 2 A 1{ 8 d I 11 1s 72<br />
(r) Pelvic injuries rn not qraigned Lcft or Rigbt in th€ codldg.<br />
Table 17. Reetrained Drivers in Frontal lmpacts<br />
Frobablc Causes of AIS 2-6 lpuer Linb Injuries<br />
I#er Linb Region<br />
Injury source<br />
A PiIlqr<br />
Faeciq Fqce/control!<br />
Lwer fagcia/parcel sh€lf<br />
ColMn/c lndding,/brackets<br />
Centre Console/Tray<br />
Peda Is /brackets<br />
Front FirEwaII<br />
Steerins t{heel<br />
6en, F@teeIl <strong>Int</strong>rusion<br />
Other vehicle,/kt object<br />
D+orllland les<br />
Other Cause<br />
Source Not hoffi<br />
Felvi! Hip fhish fs?. lp. Ankle<br />
LeE /tFt<br />
4<br />
z 6 {<br />
3 10 22 19 S 1<br />
3 3 9 5 5<br />
l 2<br />
2 6 2 L 7 s d<br />
3 5 2 7<br />
3 5 5 2 0 4 5<br />
3 3 3 1<br />
d 1 { 1<br />
6 2 1 5 4<br />
0 2 1 ? d<br />
29<br />
(2)<br />
d1<br />
TOTAI,<br />
TOTAL 2'1 66 l5 65 106 126<br />
It is recognised that lower limbs are sometimes<br />
subjected to indirect loads which give rise to injury. An<br />
example is contact to the knee or lower leg which, in<br />
addition to injuring the contacted region, may also<br />
induce a posterior dislocation to the hip or causc a<br />
femoral fracture on thc same side. Although indirect or<br />
induced injurics are noted in the database, they have not<br />
bccn highlighted in this particular analysis. Therefore it<br />
is possible that a femoral injury may be ascribed to say,<br />
gencral footwell intrusion. For ease of prescntation, left<br />
and right injuries will be combined where appropriatc. It<br />
should also be recognised that limb injuries are not<br />
mutually exclusivc since there could be one upper limb<br />
and possibly two lowcr limb injuries on the same side of<br />
a single casualty. In addition thcse limb injuries could<br />
also be concomitant with injuries to other body regions.<br />
Although diffcrent lowcr limb regions are injured by<br />
a variety of contact sources, fascia, foot pedals and their<br />
brackets and also generalised footwell intrusion are the<br />
main causes. It is confirmed that there are more contacts<br />
occurring on the right side, particulBrly in the footwell<br />
region.<br />
The probable causes of upper limb injuries are shown<br />
in Table 18. The driver is usually holding, if not<br />
gripping, thc steering wheel during the impact phasc and<br />
therefore may sustain wrist injuries due to physical<br />
bracing. The arm can also be freely moving and can<br />
therefore strike parts of the car interior, sustain an injury<br />
but leave no identifiable contact. Thercforc there can be<br />
a degree of uncertainty in ascribing injury causcs so it is<br />
not surprising that there is a very high proportion of<br />
"Source<br />
Not Known" in the data.<br />
4<br />
t2<br />
25<br />
81<br />
11<br />
10<br />
lo<br />
18 9<br />
Table 18. Heetrained Drlvers ln Frontallmpactc<br />
probable csurer ai AIs 2-6 Upper Limb InJurI?r<br />
\ tpper Linb Region<br />
Injury 5qq.** 1<br />
D@r PiIInrs<br />
Faccia/Cantrale<br />
stlerins wheel<br />
seat Belt Hebbing<br />
kr/HandIee<br />
0ther Vehicle/Ext Objrct<br />
Linb Bracins<br />
0ther CEuce<br />
Saurce N+t Kn(m<br />
LEM RIGHT<br />
shoulder Am shoulder Am<br />
7<br />
2<br />
z E<br />
1l<br />
6<br />
2l<br />
I<br />
5<br />
21<br />
1<br />
a<br />
I4 3<br />
10 1<br />
11<br />
l6<br />
3<br />
27<br />
TOTAL<br />
TtrAL 55 89 t92<br />
The steering wheel rates highly as an injury sourcc for<br />
both left and right arms with thc A Pillar as a furthcr<br />
sourcc for right arm injuries. Right shoulder injuries<br />
often occur in the higher energy impacts where some<br />
level of injury would be expected due to the restraining<br />
influence of the belt webbing. Thc upper parts of the<br />
body, including the limbs, are sometimes exposed to<br />
othcr vchiclcs and external objects during the impirct,<br />
causing contact via the broken, glazed areas where there<br />
is minimal protcction to the vehicle occupant, as<br />
illustrated in the data. Examples are severe collisions<br />
with trucks or other unyielding objects giving rise to<br />
passen gcr compartment intrusion.<br />
AhdominallLower Back Injurles. Fifty-six (l I %) of the<br />
restrained drivers sustained an internal abdominal injury.<br />
Thirteen (2-5Vo) also sustaincd a lower back injury,<br />
mainly skeletal, of which only one coincided with an<br />
abdominal injury. Fourteen (ZIVo) of the unrestrained<br />
drivers sustained abdotninal injuries and there were no<br />
recorded lower back injuries. A distribution of AIS<br />
injury levels for both groups is given in Table 19 and<br />
probatrle causes of injury in Tablc 20, rclatcd to the total<br />
suh-scl of 526 rcstrained drivers of which 68 sustained<br />
injuries lo Lhese body regions. This method of<br />
computation will be used for other Tables where<br />
appropriate.<br />
Tabb f 9. Drivers in Frontal lmpacts<br />
AIS ?-6 Distrihution, Ak)domen and Lower Back<br />
AIS /<br />
/Restraint Use<br />
Res t ra ine.f<br />
UnresL rairled<br />
2 3 5<br />
16<br />
I<br />
19 l0 2,3<br />
6 1<br />
Table ?0. Drivers in Frontal lmpacts<br />
TOTAL<br />
68<br />
l4<br />
trobablo CiurES of Al5 2-6 Abdom.inal and Loffir Bach InjutleE<br />
FeBLr{1nt. Use/Body<br />
Regl on<br />
Probable InJury :lqqrce<br />
s/wheel Rlm &/o!<br />
' Other/Part NK<br />
seatb€1t Webblng<br />
other vehlcle/object<br />
DeceI. -No Contact<br />
other ciusl-<br />
Not Known<br />
BaseIIne for ttl<br />
Abdonen Lo, Bnck<br />
N. {rl (r) N. (*)<br />
20 (4) i29)<br />
4 (1) t6)<br />
13 (2) (191<br />
9 {2) (11}<br />
2 (
It will be seen that the steering wheel components,<br />
particularly the rim, and also seatbelt webbing, were<br />
responsible for the highest percentage of abdominal<br />
injuries amongst restrained drivers. It will also be noted<br />
from Table 20 that a high proportion (76Vo) of the<br />
injuries were AIS 3-6. For the relative few unrestrained<br />
drivers, again the steering whccl gavc rise to most of the<br />
abdominal injuries. No overall conclusions can be<br />
reached for the few lower back injuries.<br />
ChestlUpper Back Injuries. Of the restrained drivers,<br />
199 (387o) sustained a chest or upper back injury. Of<br />
these, 127 (66Vo) were skeletal rib and/or sternum<br />
fractures and mainly AIS 2, l8 (97o) were internal and<br />
46 (2avo) were combined. There were only 13 (370) with<br />
upper back injuries, 12 of these coinciding with chcst<br />
injuries. Twcnty-three (34Vo) of the znrestrained drivers<br />
sustained a chest injury. Of thesc, 3 had only skeletal<br />
injurics, a further three had only internal injuries but the<br />
majority (17) had combined injuries, mainly of a serious<br />
nature. Thcre was only one upper back injury,<br />
concomitant with a serious chest injury. The AIS<br />
distribution is given in Table 21.<br />
Trbh 21. Drlvers In Frontallmpactr<br />
AIS 2-6 Distribution, Chesl/up. Back hjurieg<br />
AIS/<br />
/ResErainE Use<br />
Rest ralned<br />
UnresE ra ined<br />
2 3 4 5 6<br />
] Ib JI<br />
3 3<br />
30<br />
'7<br />
TOTAL<br />
1 2 9 r99<br />
Probable sources of injury are given in Table 22<br />
where it will again be seen that the principal cause of<br />
chest injury to the restrained driver is the steering wheel<br />
and/or seat belt wcbbing, these injuries being mainly a<br />
simple fracture of onc or two ribs and/or the sternum of<br />
AIS ? severity. Conversely the unrestrained driver<br />
sustained far more serious chest injuries, including a<br />
higher proportion of internal trauma from striking the<br />
steering wheel. The numhers of upper back injuries were<br />
too low for a meaningful analysis.<br />
Table 22. Drivers In Frontat lmpacts<br />
Probabl. Cdulca of AIS 2-ti Chegt snd Upper Brck Injurico<br />
F+strqint Uee,/Body<br />
RcEion<br />
Probable fnjqry Source<br />
steering sheel Rin<br />
5/Wheal<br />
"<br />
'<br />
Rin &/or<br />
Hub<br />
Part ffi<br />
spkea<br />
S+dtbElt HEbbing<br />
othcr vehicle/Objrct<br />
other cause<br />
Baseline for {t)<br />
Ch+rt up, hck<br />
N. lt) (t) N. (.)<br />
20 ({) (10)<br />
r'7 {3)<br />
I (2)<br />
22 t{}<br />
(9)<br />
(d)<br />
(1r}<br />
r04 t20)<br />
(5?)<br />
16 (3t (8)<br />
{ (lt (2}<br />
4 (1) t2t<br />
I Figures tm I# for Hningtql perccntagat<br />
Head, Face and Neck Injuries. Many of the injuries<br />
sustained in this group are not mulually exclusive. Of the<br />
restrained drivers, 279 (53Vo) sustained a skeletal or<br />
<strong>Section</strong> 3: Technica/ Sessions<br />
internal injury to the head, face or neck l AIS 2. The<br />
corresponding figure for the unrestrained drivers wa.s 33<br />
(49Vo). The injury severity distribution is shr-rwn in Table<br />
23, many of the face and neck injuries being concomitant<br />
with head injuries, as shown in Table 24. ln addition,<br />
there were a number of head injuries caused by a facial<br />
contact, which only resultcd in an AIS I or 2 surfacc<br />
injury to the face. The former were usually brief periods<br />
of unconsciousness and possibly some other head<br />
involvement.<br />
Table 23. Drivers in Frontal lmpacts<br />
AIS 2-6 Head, Face and Neck Injury<br />
SeveriEy Distribution<br />
Table 24. Drivers in Frontal lmpact$<br />
urtrest r'd if,d<br />
Als 2-6 HHd, Facc snd Ncck tnjurie$<br />
otrlY<br />
flead Faco Feck<br />
l?s ?1 5<br />
Fnce+ Fice+ Hend+ H€rd, Frc€<br />
Hoad ileck Nsck 4 Neck<br />
53 z'19<br />
- z<br />
33<br />
Most of the head injuries wcre of AIS 2 scvcrity and<br />
the facial injuries were mainly simple fractures. Probable<br />
injury causes ue shown in Table 25.<br />
rab re 25' ori:::ii,t["i:'<br />
BrIt Status/Head Regicn<br />
Proboble l^j!ry C6u3e<br />
Rmf/Sun Rmf<br />
Front Hedder/Visor<br />
w indsereen<br />
A Pi I lar<br />
Steelins vfh+l Fln<br />
St. Wheel Eim & $tEker<br />
steeriiln Hh+el Hub<br />
St. Wheel, ParL NK<br />
side classlbDr<br />
Bomel-tun Car<br />
oLher veh. /Frr - Object<br />
Decel. No ConEact<br />
Other C6use<br />
Causr HK<br />
Restrained Unrestrained<br />
AIS Head Face Neck Head Face Neck<br />
I<br />
4<br />
5<br />
b<br />
NK<br />
24<br />
I7<br />
tt<br />
18<br />
55<br />
'l<br />
;<br />
9<br />
E<br />
:z<br />
:<br />
i::",::: dn
lSth lnternetlonal Technlcal <strong>Conf</strong>erence on Expertmentat Safety Vehtctes<br />
Although headface/neck injury numbers of the<br />
unrestrained drivcr were small, commensurate with the<br />
smaller sample size, the highest proportion were judged<br />
to be due to windscreen contact. It is well documented<br />
from earlier, pre-scat belt wearing days that head/face<br />
contact with the windscreen was common in severe<br />
frontal impacts, often causing severe, lacerative facial<br />
injuries and undcrlying hcad trauma to the occupants.<br />
Front Seat Passengers 1F,SPs)<br />
There wcre ?06 restrained and 27 unresfiained front<br />
seflt pas$engers involved in frontal impacts with injuries<br />
> AIS 2 and again these figures will be used in<br />
subsequent analyses. There were proportionally less<br />
injuries per casualty and the corresponding figures will<br />
be presented for different body rcgions.<br />
Limb Injuries (lncluding Bttny Pelvis). As in the case<br />
of driver casualties and also indicated in Table 9, limb<br />
injuries still predominate. Of the restraincd FSP<br />
casualties, IO7 (52Eo) had limb injuries of AIS ? or 3.<br />
However the picture is again complex as these injurics<br />
were to different limb regions throughout the sub-set,<br />
often in more than onc limb, there being 158 individual<br />
limb injuries in the sub-sct. As before, such injuries were<br />
frequently concomitant with serious injuries to other<br />
body rcgions in the same ca.sualty.<br />
Sixteen of the unrestrained FSPs sustained limb<br />
injuries. Of these there was a total of 20 separatc injuries<br />
to diffcrent limb regions and the same remarks apply as<br />
for the restrained sub-set. The injury distribution for both<br />
groups is given in Table 26 and a further distribution by<br />
limb rcgion in Table 27.<br />
Table 26. FSPs in Frontal lmpacts<br />
AIS 2+ Distribution. Limb and Pelvlc Inlurles<br />
AIS Restrained UnresErained<br />
?<br />
J<br />
13<br />
J!r<br />
TOTAI, 107 IO<br />
Table 27. FSPs in Frontal lmpacts<br />
L2<br />
DiEtribution of AI5 2-6 Linb Injurier<br />
F6IVI6 HiI' Thlgh tnee Lollof, F@t Should Am TfiAL<br />
RaBt raintd z4 19 5d 158<br />
UdreEt r'ained 4 1 1 6 2 1 3 2 20<br />
There is little difference in the injury distribution<br />
between the Left and Right sides of the body with the<br />
exccption of more Lcft shoulder injuries amongst the<br />
resfrained sub-set. The probable causes of lowcr limb<br />
injury are shown in Table 28. Due to the small numbers<br />
amongst unrestrained FSPs, only those results for the<br />
restrained sub-set will be presented. As with the<br />
restrained drivers, different lower limb regions are<br />
injured by a variety of contacts, the lower fascia/parcel<br />
128<br />
shelf and also generalised footwell intrusion being the<br />
main causes.<br />
Unlike the restrained driver, who is in proximity to,<br />
and may also be gripping the steering wheel (see<br />
previous discussion), the upper limbs of the FSP are<br />
usually totally free to move during the impact phase.<br />
They can strike a variety of interior structures,<br />
principally thc fascia and also the adjacent door,<br />
particularly if intrusion is involved. As with the drivers,<br />
there are also a number of case$ where the injury source<br />
is not known. Predictably, the left shoulder sustained<br />
most injury, mainly of AIS 2 scvcrity, from the<br />
resFaining effects of thc scat belt wcbbing (Tablc 29).<br />
Table 28. Reatrelned FSF* in Frontal fmpacts<br />
prabable Csusee of AIS 2 6 her Limb Iniuries<br />
tffer Ir inb Red i (rn<br />
InJury $ource<br />
FnEciA F{celcont r+1s<br />
Lower farcia/parerl sh.lt<br />
A Pillar<br />
Fr(ilr F'ir.ew.rIl<br />
Gen. FootweII <strong>Int</strong>rusion<br />
other Vehicle/kt object<br />
0the! Cause<br />
$+urce N+t Kn+w<br />
Pelvie Hip Thigh finee Lo. Ankle<br />
Les / t@r<br />
I I0 2 5 3<br />
3<br />
1 8 1 1<br />
3 2<br />
2 2 3 2 1 2<br />
TdTAI]<br />
6<br />
z1 36<br />
20 5<br />
10<br />
TOTAL 4 n 2 5 5 23 24 B5<br />
Table 29. Restrained FSPs in Frontal lmpact$<br />
Probable CauBes of AIS 2-6 UFper lrinb Injuries<br />
\ upper Linb Resion<br />
Injury source \<br />
Fascir<br />
$est gelt Webbing<br />
Door /H&nalcE<br />
other Vehicle/tut Obj+ct<br />
other<br />
Source Not Knom<br />
LEM RICHT<br />
Sh,rulder Arm shoulder Am<br />
t2<br />
TOTAL Id 5 21<br />
10<br />
,l<br />
'l<br />
I<br />
2<br />
2<br />
10<br />
TOTTI,<br />
AbdominallLower Back Injaries. Twenty-one ( l07o) of<br />
the restrained FSPs sustained an internal abdominal<br />
injury. There were l0 (sEo) who also sustained a lower<br />
back injury, mainly skeletal, none of which appeared to<br />
coincide with an abdominal injury. Only one of the 27<br />
unrestrained FSPs in frontal impacts sustained an<br />
abdominal injury and there werc no recorded lowcr back<br />
injuries. Therefore only the restrained sub-set will be<br />
presented in the analyses. A distribution of AIS levels<br />
for the abdomen and lower back injuries is given in<br />
Table 30 and probable causes of injury in Table 31.<br />
Teble 30. Restrained FSP8 in Fronlal lmpacts<br />
AISI 2 -{r Injury Distriirut ion,<br />
Alrdomen and Lower Back<br />
AIS 2 3 4 5 TOTAL<br />
N.<br />
'r1<br />
7 7 6 JA<br />
Although the numbers are small, it will be seen that a<br />
high proportion of thc injuries wcre severe (AIS 3-6).<br />
Injury causes are distributed but it can be seen that the<br />
seat bclt webbing was rcsponsiblc lor more than the<br />
19<br />
l4<br />
I<br />
10<br />
I'7
Tabh 31. Rertralnod FsPr In Frontel lmpaclr<br />
Probable Causes of AIS 2-6<br />
Abdominal and Lourer Back InJuries<br />
Body Reqrion/<br />
Probable InjurY source<br />
FascIa<br />
other occupanE<br />
seatbelE Webbing<br />
oEher Vehicle/objecE<br />
other Cause<br />
Not Known<br />
Abdomen Lo. Back<br />
4<br />
1<br />
9<br />
4<br />
2<br />
3<br />
TOTAL 27 l0<br />
other mechanisms. Injury mechanisms for lower back<br />
injuries are always difficult to determine but contact with<br />
other occupants was judged to bc responsible for most.<br />
It is interesting to note that, for restrained drivers in<br />
frontal impacts, the current data show that only one back<br />
injury was caused by occupant contact (Table 20)'<br />
Although injury numbers are too small for full analysis,<br />
one possibility is that the rear seat passenger, having<br />
entered the car from the nearside for safcty, may have<br />
remained sitting on that side and therefore would have<br />
contacted the front passenger rathcr than the driver in the<br />
impact. The CCIS data shows that more restrained<br />
occupants sit on the nearside than thc offsidc.<br />
ChestlUpper Back Iniuries. Eighty-six (a?Vo) of the<br />
restrained FSPs sustained a chest or uppcr back injury'<br />
Of these, 52 (60Vo) had rib and/or sternum fractures<br />
only. A further thirty (357o) had internal chs51 injuries,<br />
principally of a scrious nature but 23 of these also had<br />
a concomitant skeletal chest injury. There were only four<br />
upper back injuries, none of which coincided with a<br />
chest injury. Six (22Vo) of the rrnrestrained FSPs had a<br />
chest injury, this number being too small for any<br />
meaningful analysis. The AIS distribution for the former<br />
group is shown in Table 32 and probable causes of<br />
injury in Table 33.<br />
Table 32. Restrained FSPs in Frontal lmpacts<br />
Ars 2-6 InJury Dlstriblrtiorl,<br />
Chest/UPPer Back Irrjuries<br />
2 J 5 6 TOTAL<br />
N. 5t IY 5 10 1 86<br />
Table 33. Reetrained FSPs in Frontal lmpacts<br />
Probable Causes of AIS 2-G<br />
Chest and UPPer Back Injuries<br />
Body Region/<br />
Probable Injury source<br />
Fascia<br />
searbelE webbing<br />
other Vehicle/Ext.obj<br />
Decel, No contact.<br />
other occupant<br />
other Cause<br />
NoL Known<br />
TOTAL<br />
7<br />
ChesE Up. Back<br />
N, N,<br />
3<br />
oo<br />
6<br />
1<br />
J<br />
I<br />
4<br />
82<br />
I<br />
I<br />
4<br />
a<br />
z<br />
s<br />
Sectlon 3: Technlcal Sesslons<br />
It can be seen that the principal cause of chest injury<br />
is the seat belt webbing. As mentioned, these are mainly<br />
simple rib/sternum fracturcs, a6 Q0o/o) of which were<br />
only AIS 2 severity. As in the case of the driver<br />
casualty, the next highest injury cause was due to<br />
external objects/vehicles intruding via the broken, glazed<br />
areas. Although the numbers of chest/uPPer back injuries<br />
ilmongst the unrcstrained sub-set was too low for a<br />
meaningful analysis, it is worth noting that, of these six<br />
casualties, four died from their ovcrall injurics.<br />
Head, Face snd Neck Injuries. As with the driver subset,<br />
many of the injuries in this group are not mutually<br />
exclusivc pcr casualty. Of the restrained FSPs, 83 (40%)<br />
sustained a skeletal or intcrnal injury to the head, face or<br />
neck of AIS 2-6 severity. The corresponding figure for<br />
the same body regions in thc case of the unrestrained<br />
FSPs was 15 (56Vo). As with the drivers, a numbcr of the<br />
face and neck injuries were concomitant with head<br />
injuries, as shown in Table 34.<br />
Table 34. FSPs in Frontal lmPacte<br />
Bod!, Region/<br />
Regtraint Use<br />
Re6Lra i ned<br />
Unrestra i ned<br />
AIS 2-6 hea,l, Fnce and Neck InjurieF<br />
Head Fnce Ne<br />
only only on<br />
54 7<br />
B ]<br />
k<br />
v<br />
Face& Head& Head/Faee<br />
Head Neck & Neck<br />
II 5 6<br />
- 2 1 1<br />
In addition to the figures shown in the table, there<br />
were a number of head injurics causcd by a facial<br />
contact, although this only rcsultcd in an AIS I or 2<br />
surfacc injury to thc facc. lt will tte remembered thirt<br />
surface injuries have been excluded in this Papcr.<br />
However, such impacts were usually sufficicnt to cause<br />
a period of unconsciousness and possibly some other<br />
head trauma. Therefore, and ils previously statcd,<br />
assigning injury causes to the head/face region is not as<br />
straightforward as for other hody regions and injury<br />
severity distribution is presented in Table 35.<br />
The highest proportion of head injuries were AIS 2/<br />
brief periods of unconsciousness and simplc fracturcs of<br />
the face.<br />
Tsble 35. FSP$ in Frontal lmpacts<br />
Ars 2-6 Head, Face an,i Neck Injury DistribuEion<br />
Res t.rained<br />
Unrestrained<br />
AIS Head Face Neck Head Face Neck<br />
2<br />
3<br />
4<br />
5<br />
TOTAL<br />
41 1 I<br />
8 4 5<br />
I<br />
o t r<br />
5 - 2<br />
65<br />
L7<br />
8 I<br />
1 -<br />
11<br />
Probable injury causes are presentcd in Tahlc 36 with<br />
a rcminder that fiBures/mechanisms are, in general, not<br />
mutually exclusive.<br />
I<br />
i<br />
2
13th lntematlonal rechnlcal <strong>Conf</strong>erence on Expefimentel safety vehlctes<br />
Teble 36. Restralned FSPs In Frontel lmpacte<br />
Ptobabl. Causes of AIS 2-6 Hsd, Fcc+ and Neck InjurieE<br />
B+]t strtqs/Head Region<br />
Probablc Injury Cdus.<br />
Front Hsder/Vidor<br />
Hindscr+cn<br />
A PiIldr<br />
stc6rlnd tJh??I<br />
BoM+t-Ovn Car<br />
othcr Vlh./ht. objcct<br />
DrcGL No ConLact<br />
Obh+t Cau!!<br />
Cause ffi<br />
FesLra ined Unrist16 i ncd<br />
Hcad Face Neck Head Face Neck<br />
2 -<br />
A 2<br />
2 "<br />
L 7 4<br />
3 2<br />
1 0 2<br />
8 -<br />
3 1<br />
1 d 1<br />
l<br />
;<br />
9<br />
I<br />
f<br />
2 1<br />
2<br />
2 3<br />
TOfAL 65 12 7'l II d<br />
Not surprisingly, it will be seen that the main cause of<br />
facial and head injury to restraincd FSPs is due to<br />
contact with the intcrior structures ahead of the occupant<br />
and the data identifies the contrflct zones. The fascia and<br />
also other vehicle/external objects making contact via the<br />
glazed areas featured highly for this group. Although<br />
absolute numbers are small, it is worth noting that a<br />
higher proportion of head/neck lesions amongst the<br />
restraincd sub-set were judged to be due to deceleration<br />
without any physical contact to the cranium whcn compared<br />
to the unrestrained group. This is due to thc hcad/<br />
neck jerking forward whilst the trunk is restraincd by thc<br />
seat bclt giving the classic, violent forward flexion<br />
followed by hyperextension as the head is thrown back.<br />
Unrestrained Rear Seal Passengers (R.TPs)<br />
Reference to earlier <strong>Section</strong>s and Tables indicated that<br />
restrained RSPs were in the minority and thereforc<br />
analyses will concentratc on thc unrestrained sub-set of<br />
which there were 120 casualties with AIS 2-6 injuries<br />
involved in frontal collisions. Due to the distribution of<br />
rear seating positions and a proportion where this was<br />
not known, seating positions have been combined in thc<br />
analyses. Although it is appreciated that full injury<br />
mechanisms cflnnot be explored in this way, a general<br />
indication will be given for frontal impacts only.<br />
Limb Injuries (Irttluding Bony Pelvis). Of the 120<br />
casualties in this sub-set, 68 sustained limb injuries<br />
(57Vo). However some were multiple, there being a total<br />
of 103 such injuries of AIS 2 or 3 in this sub-set and<br />
distributcd amongst different limb regions as shown in<br />
Table 37.<br />
Table 37. Unreetrained RSPs in Frontel lmpects<br />
Distributian of AIS 2-6 t itr\b Injilr ier<br />
Pelvic Hip Thigh l{ncc la/Ios Fmt should Am TOTAL<br />
5 I{ z d6 103<br />
Almost half the limb injuries were to the arms, mostly<br />
on the left. This difference is not necessarily significant<br />
as much depends upon seating position prior to impact.<br />
The causes of limb injuries have not been tabulated<br />
because it was reasoned that the majority were due to<br />
contact with the front seat but contact marks are<br />
130<br />
I<br />
frequently difficult to either observe or differentiate from<br />
in-use scuff marks on the seat material.<br />
AbdominallLower Back Injuries. Thcre were only 20<br />
casualties (l7Vo) in the subset who susrained injurics to<br />
thcsc body regions and hence the injury causes have not<br />
been tabulated. Of these, 12 were caused by striking the<br />
rear of the front seat, most of the others by contacting<br />
different internal structures and three relatcd to ejection<br />
from the vehicle. The AIS severity distribution is given<br />
in Tahle 38 and shows that such injuries were severe and<br />
often fatal.<br />
Teblo 38. Unrestrained RSPs in Frontal lmpacts<br />
AIS 2-6 Injury Distrilrution,<br />
Abdomen and Lower Back<br />
AIS 2 3 4 5 TOTA],<br />
N. 3 A 20<br />
ChestlUpper Back Injuries. There were 24 injuries in<br />
this category (20Vo) and the AIS severity distribution is<br />
given in Table 39. As with the abdomen, it will be seen<br />
that many of thesc injuries arc severe. Probable injury<br />
causes are shown in Table 40 where it is seen that<br />
striking the front seat is the most common cause of chest<br />
injury in lhis sub-set. Again there wils it proportion of<br />
"Not<br />
Known's."<br />
Table 39. Unrestralned RSPs In Frontal lmpac-ts<br />
AIS 2-6 Injury DisEribution, L-hesE altd Upper Back<br />
? 3 4 5 6 TOTAI<br />
N, J 7 3 9 2 24<br />
Table 40. Unrestrained RSPs in Frontal lmpects<br />
t'robable Als 2-6 lnjury causes, chest and upper Back<br />
caus e bor/B pIIlar Dther seat Ejectloil oLher NK<br />
.I$TAI,<br />
N I I l 6 24<br />
Head, Face and Neck Injuries, Sixty-eight (57To)<br />
sustaincd a hcad, facc or neck injury of AIS 2-6 and<br />
Table 4l gives the AIS distribution of thc 88 scpflrate<br />
injuries. This shows a high proportion in the AIS 2<br />
catcgory which, as previously mentioned, usually<br />
significs short periods of unconsciousness. There is also<br />
a significant number of severe head injuries as indicatcd<br />
by the higher score$. As with thc other occupant<br />
casualties, a head injury is sometimes concomitant with<br />
a face and/or neck injury (Table 42).<br />
Tsble 41 . Unrestrained RSPs In Frontal lmpacts<br />
AIS 2-b Irriury Distribut-ion, Heari, Face and Neck<br />
Head<br />
Neck<br />
2 3 4 5 6 TOTAL<br />
30 16 6 1 3<br />
1 1 1 1<br />
2 3 2<br />
62<br />
l9 1
Tebh f2. Unrostralned F$Pr In Frontal lmpecls<br />
AIs ?-6 Head, Face and Neck Injuries<br />
Bod!. Fegion Bead F6ce Neck Frce & H€ad & Head,face<br />
only only qnly Head fleck & Neck<br />
N 4l { 2 I4 4 1<br />
Probable cau!$e$ of injury are given in Table 43 which<br />
shows the majority occurring in the roof/header rail arca.<br />
Again there is a high proportion of "Not Known's" and<br />
some due to ejection of the unrcstrained occupant from<br />
the vehicle following impact.<br />
Table t1.3. Unrestrained FSPg in Frontal lrnpacts<br />
Probable AIs 2-6 Injury Causes,<br />
Head, Face and Neck<br />
Probable Cause Head Face Neck<br />
Roof/Header RaiIs<br />
Fascla Afea<br />
Pi llars /Door<br />
Front. Seat/Headreat<br />
Rear Seati<br />
Ej ect ion<br />
Other Vehicle<br />
OLher Ca\rse<br />
Cause NK<br />
1 0 2<br />
o z<br />
5 I<br />
8 3<br />
2 L<br />
5 2<br />
2 T<br />
4 2<br />
20 5<br />
TOTAL ol 19 1<br />
Side Impacts<br />
Although the highest proportion of accidcnt impacts<br />
are to the vehicle front (Table l), there is concern<br />
amongst accident researchers and vehicle designers<br />
regarding the vulnerability of occupflnts in side impacts.<br />
This is mainly due to the closc proximity of the adjaccnt<br />
door and that the vehicle is often supported by the struck<br />
or striking object during the impact phase, causing rhe<br />
occupant to contact an unyielding structure. This is in<br />
some contrast to the relatively greater protection offered<br />
by the vehicle front structure in frontal impacts. The<br />
passenger comparlment itself is involvcd in most side<br />
impacts (Table 3) and injury mechanisms will be<br />
explored in a similar way to the analyses for frontal<br />
impacts but considering the impact direction rclarive to<br />
the occupant's scating position. Therefore a driver<br />
involved in an offsidc impact would be consirlered sitting<br />
on the "struck-side"<br />
and any front seat passenger on the<br />
**non-struck<br />
side." For a nearside impact, the converse<br />
would apply. Using this principle, data on Drivers and<br />
FSPs will be combined as Front Seat Occupanrs (FSOs).<br />
Front SeaI Occupants (FSOI) in Struck-side Impacts<br />
As indicated, data for restraincd front seat occupants<br />
involved in --struck-side"<br />
impacts have becn combined<br />
ie, drivers involved in an offsidc and a front passengcr<br />
involved in a nearside impact. There were l7l injured,<br />
restrained FSOs (114 drivers and 57 FSPs) and also ?2<br />
unrestrained FSOs in struck-sidc impacts and again these<br />
figures will be used in subsequent analyses and be<br />
presented for different body regions.<br />
I<br />
. ')<br />
Sectlon 3: Technlcal Sesslons<br />
Limb Injuries (Including Bony Pelvis). One hundred<br />
casualties (59%) in the restrained subset susteincd a limb<br />
injury. As in the previous analyses, a proportion sustained<br />
injuries to mure than one limb region, there being<br />
206 individual limb injuries amongst these casualties.<br />
Thirteen (597o) of the unrestrained FSO casualtie$<br />
sustained a limb injury. However, when brokcn down<br />
into individual limb regions, the numbers for the latter<br />
group would be too small for meaningful analysis and<br />
have therefore not been reported. However it is worth<br />
noting that, o/ the 72, over half died of multiple injuries.<br />
A distribution by individual limb region for the<br />
restrained FSO sub-set is given in Table 44. Since<br />
offside and nearside impacts arc being combined, it is<br />
necessary to differentiate belween the lcft and right<br />
limbs in relation to the impact. They have bccn designated<br />
"adjacent"<br />
(nearest thc strlct side) and *'remote"<br />
for the conver$e.<br />
rabre44'**:Tl:::,:"t:"^,'"",T1",:*;:,'::""''0"*"<br />
RffiE.<br />
Adjacctrt<br />
PtrIvir' Hip Thish Lolleg Fmt should Am TOTAL.<br />
{46)<br />
20 2t<br />
I<br />
t6<br />
5<br />
I<br />
{ 9<br />
27 2l<br />
42<br />
(46)<br />
108<br />
?MAL td6j * 24 35 24 1d tl t? 205<br />
Pelvic Injurj.ls are not aerign+d Lett/Riqht iD the coding<br />
Not surprisingly, as struck-side impacts are bcing<br />
considered, there were more injuries to the adjacent side<br />
of the body compared to the rcmote by a factor of<br />
approximately 3: I overall - or more if pelvic injuries can<br />
be attributcd to struck-side impacts. Probable injury<br />
causes are presented in Tables 45 and 46.<br />
r a b I e 45'<br />
*-<br />
T,T"'J:' :::"::i="'1,=::.: Tl::',:, :: ::<br />
Linib Rqion<br />
lnjury -qource<br />
Adjtc.nt hr/Pill.E<br />
Other Vchicl./E*t. ObJcct<br />
Cch, Ffttw?l1 rntrusion<br />
P+\C.lclJorAsk?t ry<br />
Other Cauge<br />
bny<br />
Pelvi.E<br />
t5<br />
20<br />
1<br />
HiF Thigh ttu?r kkle<br />
Leg / f $)t<br />
Adiac.nt Limbs<br />
16 -fit--E-<br />
z<br />
2 6 ' ?<br />
2 1<br />
TgIAL<br />
TtrAL 46 2 0 2 1 1 6 8 68<br />
Adjrcenr hr,/PilIare<br />
Other Vchial+/Ext, otJject<br />
G.n, FFtweII <strong>Int</strong>rusi04<br />
fther Caure<br />
CauEe M<br />
Remte lrinbs<br />
l T " . _ 1<br />
5<br />
2 7 a<br />
1 1<br />
T}TAL {6 { 11 S 6 29<br />
ec ludins injuri+r ehich arr not cllded Lett ar Pight sidc<br />
Table 46. Rastrained FSOs in Struck-side lmpact$<br />
Linb Region<br />
Injury source<br />
D
lSth ,ntematlonel Technlcal <strong>Conf</strong>erence on Expeilmental Safety Vehtcles<br />
It is not surprising to observe that adjacent door/pillars<br />
are the principal cause of limb injury. The other important<br />
thing to note is that, at the moment of impact and<br />
for part of the accident phase, the door can remain<br />
loaded hy (usually) the striking vehicle or an unyielding<br />
structure thereby offering a stiffer structure against<br />
which the occupants sustain their injuries. Therclore the<br />
injury cause is more relatcd to this solid structure,<br />
particularly if it intrudes into the pilssenEer compartmcnt.<br />
This will also apply to some other body region injuries.<br />
The data also shows that some injuries are caused by<br />
a structure not normally adjacent to the body region in<br />
question. Thcre is often violent occupant movement<br />
(particularly limbs) during the impact phase coupled with<br />
some vehicle spin and also passenger compartment intrusion.<br />
Therefore the occupant limb positions arc often<br />
very different from thosc of the normal riding mode.<br />
AbdominallLower Back Injuries, Fifty-one (307o) of<br />
the restrained FSO casualties sustaincd an injury to the<br />
abdomen and/or lower back (principally the former). The<br />
severity distribution is shown in Table 47 and probable<br />
injury cause in Table 48. Therc were only l0<br />
unrestrained FSOs in this group, this number bcing too<br />
small for a meaningful analysis.<br />
Tsble 47. Restrained FSOs in Struck-slde lmpacts<br />
AIs 2-6 rnjury severity DisEribuEion,<br />
Abdomen and Lower Back<br />
2 3 A 5 TOl'AI<br />
N, I3 16 T2 10<br />
Table 4$. Hestrrlned F$OC In Struck-eide lmpacts<br />
Probablc<br />
Cause<br />
Frobabls AI5 ?-6 Injury caureB, Abdomen and kw+r E.rck<br />
Adjrcent dwr mt Seatbelt other VGh. Other<br />
/pIIIer handleB webbitrg Ext. Object Ceus+<br />
TOTAL<br />
N, 23 11 51<br />
The abdomen lacks skeletal protection and the data<br />
shows the levcl of serious injury sustained. Again the<br />
adjacent door was the principal causc with other<br />
vehicle/external objects also featuring highly.<br />
ChestlUpper back Injuries. Seventy-seven (457a) of<br />
the rcstrained FSOs sustained an injury to the chcst<br />
and/or upper back (principally the former). Thc severity<br />
distribution is shown in Table 49 and the probable causes<br />
in Table 50. As before. the few unrestrained casualties<br />
with injurics to this body rcgion have not been reported.<br />
Table 49. Restrainsd FSO$ in Struck-slde lmpacts<br />
AIS 2-6 Injury Severity Distribution,<br />
Chest and Upper Back<br />
AIS 2 3 5 6 TOTAL<br />
N, 24 19 T4 l0 l0 71<br />
Table 50. Hestrained FSOs In Struclt-side lmpacts<br />
Prcbbls AIS 2.6 InjulT causes, Ch€st {nd UFFcr Back<br />
CAU$H Adjacent d@r Cther fther Seat other veh, Otber Cause<br />
/pirlars Occ, Ssnt fJelt Ext. Object Cf,u+s NR<br />
H, 23 I 2<br />
TOTAL<br />
Table 49 indicates the seriousness of the injuries in<br />
this group, including a proportion of fatals. The causal<br />
pattern is the same as for abdominal injuries, namely the<br />
adjacent door and external impacts from othcr vehicles<br />
and objects. A smaller proportion of the chest injurics<br />
were attributcd to the restraining effect of the seatbelt<br />
webbing. <strong>Int</strong>eraction bctween the casualty and the<br />
adjacent seat and/or occupant also featured.<br />
Head, Face and Neck Injuries. Ninety-one (53Vo) ot<br />
the restrained occupant casualties in this group sustained<br />
injuries to thc head, face or neck, mainly the former and<br />
the injury distribution is shown in Table 51.<br />
Table 51. FSOs In Struck-side lmpact$<br />
A.tS 2-6 Hea(:l. Face and Neck In jury Distribution<br />
* Drivers only<br />
Howevcr, some coincidcd with other cranium injuries<br />
(Table 52) and, as before, most hcad injuries were of<br />
AIS 2 severity/brict periods of unconsciousness.<br />
Table 52. FSOs in Struck-side lmpacts<br />
Body Region/<br />
Resgteint use<br />
Restrn i ned<br />
Unresqrd i rredr<br />
* Drlvers only<br />
Res t rained Unrestrained*<br />
AIS Head Face Neck Head Neck<br />
2<br />
3<br />
5<br />
6<br />
5 2 8<br />
ls 3<br />
8 *<br />
4 -<br />
9 -<br />
AIs 2-6 Head, Face and Neck Injuries<br />
Hend Fdce N€ck Face & Head & H€ad.Face<br />
only anly only Hend Neck & Ncch<br />
'l<br />
66 3 1<br />
I r<br />
10 - l<br />
In a smaller sample of injured unrestrained drivers, l3<br />
out of l7 sustained a hcad or neck injury. Half of these<br />
dicd from multiplc injuries, including the head lnd/or<br />
neck region.<br />
It will be seen that head injurics predominate, the<br />
highest proportion being AIS 2/brief periods of<br />
unconsciousness. Probable causes of these injuries are<br />
prcscnlcd in Table 53 with a reminder that figures/<br />
mechanisms for this particular body region arc not<br />
mutually exclusive.<br />
The most common cause of injury in this group was<br />
contilct with another vehicle/external object, usually via<br />
the brokcn glazed area. Thcre was also a significant<br />
number of contacts with the adjacent door/pillars and<br />
2<br />
:<br />
3<br />
4 1<br />
z 2<br />
5 -<br />
2 l<br />
TO,IlAL 88 IT L0<br />
LJ 4<br />
'1'l
Tabh 53. Hesiralned FSOs In Struck-slde lmpacts<br />
Probable AIS ?-6 Injury Caus,--s, Head. Face ancl Neck<br />
Probablc CauaG<br />
Roof/Side headGr<br />
AdJacent door,/Plllars<br />
Side GIaE6<br />
Other Occupant<br />
Other Veh.,/Ext. objecE<br />
Decel. No contacL<br />
Other Cau6e<br />
Cause NK<br />
r DriverE only<br />
Re stra ined Unrest.rained*<br />
Head Face Neck ttead,/Neck<br />
1 2 2 -<br />
2 - l<br />
2 4 5 {<br />
10 * 4<br />
{ -<br />
1 2 1 1<br />
TdTAL 88 1 1 10<br />
side glass. A lesser percentage of head and neck injuries<br />
were due to deceleration without noticeable hcad contact.<br />
Restrained Front Seat Occupants ln Non-strack<br />
Side Impacts<br />
As with the struck-side analyses, data on restrained<br />
FSOs have been combined. Therefore drivers involved in<br />
nearside and fronl passengers in offside impacts have<br />
been considered of which there were a total of 109<br />
casualties (84 drivers and 25 FSPs). There were only 9<br />
unrestrained drivers in this impact ciltegory and, when<br />
their injury patterns were further broken down into<br />
individual limb rcgions, thc final figurcs were<br />
insufficient for meaningful analysis.<br />
Limb Injuries (lncluding Bony Pelvis). Forty-six (42Vo)<br />
'of a sub-set (32 drivcrs and 14 FSPs) sustained limb<br />
injurics > AIS 2. The distribution is given in Tabte 54<br />
and again it is necessary to define limb side in rclation<br />
to the side of the vehicle that has been impacted. Using<br />
the previous convention, a driver's Left leg in a nearside<br />
impact is classified as "Adjacent" whilst the Right leg in<br />
thc samc impact would be classified as "Remote."<br />
For a<br />
front seat passenger in an offside impact the converse<br />
would apply for the Right and Left limbs. This convention<br />
is not totally accurate as say, an adjar:enl limb<br />
would strictly be more in the middle of the car at rhe<br />
time of impact. However the same terminology has been<br />
used for consistency.<br />
Tible 54. Heetralned FSOe In l.lon-struck Sfde fmpacte<br />
LInb<br />
side<br />
Adjaccnt<br />
(9)<br />
I<br />
7<br />
Distribution ot AIS 2-6 Linl, Injur.i.-.:<br />
Felvis' Hip Thish bwer Fmt/ shoulder Arm<br />
t+g ankle<br />
I<br />
I<br />
5 9<br />
6 1l<br />
' Pclvic injurica ir. not rsslgnfd Lcft/Right in thr ccding.<br />
2<br />
2 I<br />
;<br />
i<br />
1<br />
TOTAI.<br />
Most injurie$ occurred to the uppcr limbs and, as the<br />
individual numbers are small, probable causes have not<br />
been tabulated. Most of thc driver's pelvic injuries were<br />
due to the transmission tunncl and wcre probabty indirect<br />
arising out of contact with one of the lower limbs. Upper<br />
limb injuries were judged to be due to contact with thc<br />
other occupant or door with a number of Not Known's.<br />
Abdomenl Lower Back I njuries. Twenty-three (TlVo)<br />
sustained abdomen and/or lower back injurics. Thc<br />
(9)<br />
Sectlon 3: Technlcal Sesslons<br />
severity distribution is given in Table 55 and shows a<br />
high proportion of AIS 3-6 injuries (18/23).<br />
Tablc 56 shows the distribution of probable injury<br />
causes, the largest classification being due to the effects<br />
of another vehicle/external object. Again some of these<br />
injuries can be in the rebound category.<br />
ChestlUpper Back Injuries. There were 34 casualties<br />
with injurics to this body region (3lVo of sub-set) and<br />
Table 57 again shows that over half were severe (AIS 3-<br />
6). All sustained rib fractures, the majority being simplc<br />
at AIS 2 level. Table 58 shows that the causal pattern is<br />
not dissimilar to that for thc abdomen but with more<br />
interactive-type injury mechanisms.<br />
Tabh 55. Resilsined FSO8 in Non-etruclr Side lmpactr<br />
AIS 2-6 InJury Severity Dierrilrrrt-Lorr,<br />
Abdomen and Lower Back<br />
2 3 4 5 TOTA],<br />
N, 5 8 1 3 IJ<br />
Table 56. Hestrained FSOs in Non-struck Side lmpects<br />
Probdble AIS 2-6 Injury Causes, Abdomen and bwer tsack<br />
Caqse DFr Other SeFtbell Other veh. Other L'ause<br />
Occupant EIt -Object Cauee ffi<br />
N, 2 1 4<br />
Table 57. Hestreined FSOs In Non-struck Side lmpaets<br />
AIS 2-6 Injury SeveriLy DisLribuLion,<br />
Chest and UDDer Back<br />
2 3 4 5 6 TOTAL<br />
N. 1 4 8 5 2 5 34<br />
Tabls 58. Restrained FSOs in Non-struck Side lmpacts<br />
Prabqble AIS ?-5 Injury Cauaee, Cheat and Upper Back<br />
Caucc Dftr other other seat other Veh. other Cause<br />
Occ. seat belt Ext .Object C6use NX<br />
TMAL<br />
N. 5 5 5 9 2 3 fd<br />
Head, Face and Neck Injuries. There were 64 injuries<br />
to the head and 7 to thc [ace, a total of 7I. All but 2 0f<br />
thc latter were concomitant with other head injuries.<br />
Table 59 shows, as before, that the majority were AIS 2<br />
and, since they were in thc rnajority, only head injury<br />
causes are presented in Table 60.<br />
Table 59. Restrained FSOe in Non-struck Side lmpacts<br />
AIS 2-6 Injury Severi[y Distriirution,<br />
Heird. Face atrd Ner:k<br />
AIS 2 3 4 5 6 TOTAI<br />
Head<br />
Face<br />
28 11 6 12 7<br />
5 2<br />
Although not specifically presented, it can bereasoned<br />
that mirny of the door/pillar assigned contacts could be<br />
64 '7<br />
TOTAI,<br />
133
13th lntematlonal Technlcal <strong>Conf</strong>erence on Experlmental Safety Vehlcles<br />
either rebound injuries or the result of gross intrusion<br />
towards the non-struck side of the vehicle.<br />
Table 60. Hestrained FSOs in Non.rtruck Side lmpacts<br />
PrchbI€ CauB€s of AIS 2-6 H+ad Injq<br />
borE/ stesrinE side fther veh. / Decsl. othsr caua€<br />
pillars heel Glass Ext, Obrect No Contect Cause M<br />
TtrE<br />
e l t8 7 6n<br />
As in the case of struck-side collisions. intrusion into<br />
the occupant space of othcr vchicle/cxtcrnal objccts also<br />
featured highly-as well as a proportion in the **Not<br />
Known" category.<br />
Discussion and Concluding Remarks<br />
It is no sutprise that the data show the majority of<br />
impact$ are to thc vehiclc front with the highest<br />
proportion offset to the right. In a previous CCIS<br />
investigation by Ashton et al [6] it was found that such<br />
impacts are largely the result ofoffset head-on collisions<br />
on unrestricted roads.<br />
The data also show that. in terms of total numbers,<br />
head and limb injuries predominate. Although thc lattcr<br />
are not life-threatening when taken in isolation, they<br />
often coincide with somctimcs serious injuries to other<br />
body regions.<br />
In a proportion of cases, lower leg injuries occur when<br />
there is entrapment of the casualty in the vehicle and<br />
there are also a higher percentage of multiple injuries in<br />
side impact collisions. If the door itself is grossly<br />
distorted and jammed following impact, rescue is invariably<br />
delayed, despite the sophisticated cutting equipment<br />
carried by emergency vehicles. If there are lifethrcatening<br />
injuries present, such a delay could<br />
compromisc eventual clinical recovery of the patient,<br />
despite improvcments in roadside medical care.<br />
Therefore these points must be borne in mind when<br />
considering vehicle design improvements, particularly in<br />
side impact protection.<br />
The analyses clearly show that lower fascia contact,<br />
footwell intrusion and foot pcdal entrapment are the<br />
principal causes of lower leg injuries amongst drivcrs.<br />
lnstances have been found where, although thc fascia<br />
surface is compliant, it is sometimes supported by an<br />
aggressive structure. Therefore the above injury-causing<br />
structures warrant further consideration, particularly in<br />
relation to the frontal impact situations prcviously<br />
mentioned.<br />
Thc results show yet again that steering wheel contact<br />
is rcsponsible for the majority of restrained drivers'<br />
facial contact in frontal impacts, producing as it does<br />
concomitant and often serious head injuries. It is<br />
accepted that initiatives have been taken on producing an<br />
occupant-friendly steering wheel assembly, more recently<br />
reported hy White et al [8]. The data anulysed in this<br />
report has not differentiated between wheel types.<br />
134<br />
Implementation of these improved designs must remain<br />
a priority itcm.<br />
Many of thc hcad injuries recorded in thc data are<br />
brief periods of unconsciousness caused by the hcad<br />
either striking the internal structure or external<br />
structures/other vehicles. Non-contact head injuries are<br />
also recorded, producing a similar clinical outcome.<br />
Although these periods are brief, they should not be<br />
dismissed lightly as latent head trauma, epilcpsy and<br />
recurring hcadaches are a possibility following unconsciousness.<br />
The steering wheel and seatbelt webbing, often in<br />
combination, are again the principal causes of chest and<br />
abdomen injuries for the rcstrained drivcr in frontal<br />
impacts. It has long been accepted that seatbelt-relatcd<br />
injuries are the lesser<br />
--penalty"<br />
of wearing restraints<br />
when compared to the more serious and fatal injuries<br />
sustained by those who still choose not to wear their seat<br />
bclts. The majority of the recorded chest injuries were<br />
AIS 2, usually one or two sinplc rib fractures and an<br />
increase in this type of injury following the introduction<br />
of the 1983 seatbelt legislation was prcclicted by<br />
Rutherford et al [7] who also indicated a likely reduction<br />
in overall injuries. However the elderly population are<br />
morc susceptible to skclctal fraclurcs and it is prcdictcd<br />
that half thc population will be over 55 years of age by<br />
the year 2000 with many of thcm drivcrs. Therefore the<br />
question of (particularly rib) fracturc causation and<br />
possibly underlying soft tissue damagc must be<br />
addressed.<br />
The Scctions on side impact collisions discuss the<br />
relative vulncrability of occupants when compared to<br />
frontal impacts. The data quantify the relative injury<br />
severity and it is no surprise that contact wltft the door<br />
is the principal cause of side-impact chest, pelvis and<br />
uppcr lcg injuries. It has also been shown that<br />
striking/struck objects often remain in contact with the<br />
"cilse"<br />
vehicle door during the impact phase. This tends<br />
to producc an unyiclding structure against which most<br />
injuries occur.<br />
A considerable number of head and chcst injuries were<br />
sustained due trl contact with another vehicle/structure,<br />
usually intluding via the glazed areas, particularly in side<br />
impilcts. Although the fitting of laminatcd sidc glass may<br />
go somc wily to reducing albw of thcsc injuries, ilttention<br />
will possibly havc to bc focuscd on door/sill<br />
strengths to partially prevent intrusion of these outside,<br />
full height structures. It is appreciated that concern over<br />
injuries sustained in side impacts and potential solutions<br />
is receiving worldwide attention. However frontal collisions<br />
are still in the majority so a combined approach to<br />
frontal and side impact protection must remain a goal.<br />
For the restrained front seat pas$enger in frontal<br />
impacts, the intruding lower fascia was the cause of the<br />
mirjority of thigh injuries. A proportion of trunk injuries<br />
were also caused by this mechanism but the majority,
particularly to the chest, were caused by the restraining<br />
effect of the seat belt webbing. Again, many of these<br />
were simple rib fractures of AIS 2 severity with thc<br />
same remarks applying as for the restrained drivcr. These<br />
and footwell intrusion for injuries to the lower legs have<br />
already been mentioned.<br />
Thc difficulties of assigning injury cause$ to the<br />
(sometimes) flailing upper limbs have been discussed.<br />
However thcre is a dominant involvemenl of the stecring<br />
wheel in the casc of the driver and seatbelt webbingrelated<br />
shoulder injuries for both restrained FSOs.<br />
Many of the rear seat casualties in the sample were<br />
unrestrained and the earlier data identified a high<br />
proportion of the young and elderly. All modern cars<br />
now have rear restraints fittcd and legislation has been<br />
introduced for compulsory wcaring by all occupants<br />
seated in the rear where a restraint is available. This<br />
legislation is important as the data from this and other<br />
sturlies clearly show that unrestrained vehicle occupants<br />
sustain greater levels of serious and fatal injury in<br />
accidents. What the data a/sa show is that most of the<br />
contacts for unrestrained RSPs in frontal impacts are to<br />
the front seats. Not only can this produce injury to the<br />
RSP, but also loads the front seat and therefore its<br />
occupant. Although this is not brought out in the<br />
analysis, such loading can either cause primary injurics<br />
to the FSOs or aggrflvate any previously sustained by<br />
them in the impact. Ejection of unrestrained rcar seat<br />
occupant$ from thc vehicle following inrpact has also<br />
been recorded, usually with serious or fatfll<br />
'<br />
consgquencES.<br />
The wearing of available restraints for all occupants<br />
is vital as there seems little point in striving for<br />
meaningful improvements to restraint systems if they are<br />
not going to bc worn. Enforcement should take a higher<br />
profile.<br />
Acknowledgements<br />
The work dcscribed in this Paper forms part of the<br />
programme of the Transport and Road Research Laboratory,<br />
commissioned by the Vehicle Standards and<br />
Engineering Division of the Department of Transport,<br />
and thc Paper is published by permission of rhe f)irecror.<br />
Collcction of the data depends on the voluntary<br />
cooperation of many individuals and agencies without<br />
which the projcct would nor be possible. Gratitude is<br />
therefore expressed to the following:<br />
Thc Chief Consrables and thcir staff in rhe seographical<br />
areas covered by the study.<br />
Thc Hospital Consultants and their staff, paflicularly<br />
the medical secretaries in the piuticipating hospitals.<br />
H M Coroners, Procurators Fiscal and thcir oflicers.<br />
The management and staff, both scientific and<br />
administrative, of the Accidcnt Research Units at<br />
Loughborough and Birmingham.<br />
Sectton 3: Technlcal Sesslons<br />
Co-Sponsors Ford, Rover Group and more recently,<br />
Nissan Cars.<br />
Staff at the DTp's Vehicle Inspectorate's Headquarters<br />
at Bristol and particularly the many Vehiclc Examincrs<br />
in participating Rcgions.<br />
The authors would like to acknowledge the efforts of<br />
Martin Renouf and Jeff Meades who have developcd and<br />
managed the comprehensive, computerised database used<br />
in the study.<br />
References<br />
I. MACKAY G M, M D GALER, S J ASIITON and P<br />
D THOMAS. Thc Mcthodology of In-Depth Studies<br />
of Car Crashes in Great Britain. SAE Paper 850556.<br />
Detroit. 1985.<br />
2, GALER MARGARET M, G M MACKAY, S<br />
CLARKE and S J ASHTON. The Causes of Injury<br />
in Car Accidents - an Overview of a Major Study<br />
currcntly underway in Britain. Proceeding.s of the<br />
l0th <strong>Int</strong>crnational <strong>Conf</strong>erence on Experimental<br />
Safety Vehicles. Oxford, July 1985.<br />
3. RENOUF M. A Car Accident Injury Database:<br />
Overview and Analyses of Entrapment and Ejection.<br />
Transport and Road Research Laboratory Report RR<br />
3?0, Transport and Road Re.search Laboratory,<br />
Crowthorne, England, 1991.<br />
4. The Abbreviated Injury Scale, 1985 Revision.<br />
Association for the Advancement of Automotive<br />
Medicine, Des Plaines II, 60018, USA.<br />
5. Collision Deformation Classification. Report of the<br />
Automotive Safety Cornmittee. SAE Report J224,<br />
March 1980.<br />
6. ASHTON S J,P D THOMAS, PL HARMS,G M<br />
MACKAY and M D GALER. The Effects of<br />
Mandatory Seatbelt Use in Great Britain.<br />
Proceedings of the lOth lnternational <strong>Conf</strong>erence on<br />
Experimental Safety Vehicles. Oxford, July 1985.<br />
7, RUTHERFORD W H, A GREENFIELD H R M<br />
HAYES and J K NELSON. The Medical Effects of<br />
Seat Bclt Legislation in the United Kingdorn. DHSS<br />
Report No. 13, HM.SO, London, 1985.<br />
8. WHITE M, K CLEMO and S PENOYRE. Safer<br />
Stccring wheels to reduce face hone fractures.<br />
Proceedings of the lzth <strong>Int</strong>crnational <strong>Conf</strong>erence on<br />
Experimental Safcty Vchiclcs. Gdteborg, Sweden,<br />
1989.<br />
Crown Copyright. The views expressed in this Faper are<br />
not neccssarily those of the Department of Transport.<br />
Extracts from the text may be reproduced, except for<br />
commercial purposes, providing the source is<br />
acknowlcdgcd.
lSth lntarnatlonel Technlcal <strong>Conf</strong>erence on Experlmentel Sefety Vehlcles<br />
st.w-17<br />
The Use of Crash Injury Research Data by the Vehicle Inspectorate<br />
to Identify Secondary Safety Concerns<br />
Alan Bowker<br />
Department of Transport<br />
Abstract<br />
This paper hriefly details the current arrangements in<br />
Britain for examining road vehicle crashes and the<br />
causes of injury to vehicle occupants. The use of this<br />
data by the Department of Transport's Vehicle Inspectoratc<br />
to examine vehicle secondary safety performance is<br />
described. In addition to providing research dflta for<br />
consideration by vehicle manufacturcrs when formulating<br />
new model designs, this accident data has been analysed<br />
with some success in order to identify what design or<br />
manufacturing related features of current models could<br />
be usefully improved.<br />
Corrective action by the vehicle manufacturer within<br />
the current model lifespan will assist in reducing the<br />
number or severity of occupant injuries attributed to that<br />
model. The earlier in the model lifespan that any design<br />
related concern$ can be idcntified and correctcd, the<br />
greater will be the total saving in occupant injuries.<br />
Some examplcs of the type of analyses which can bc<br />
undertaken using this data is described.<br />
<strong>Int</strong>roduction<br />
Vehicle accidents are investigated in the UK by the<br />
Vehicle Inspectorate for a variety of reasons. These<br />
include the provision of expert vehiclc examination<br />
information to support thc police or to providc crashed<br />
vehicle data to research bodies such as the Departntcnt's<br />
Transport and Road Research Laboratory (TRRL). A<br />
primc objective for VI however, is the idcntification of<br />
vehicle design or manufflcturing defects which may have<br />
contributed to the cause of the accidcnt or to the severity<br />
of the injurics received by the vchicle occupants or other<br />
road users. Through analysis of accident data which is<br />
primarily collected for research purposes, early<br />
additional bcnefits in occupant protection and injury<br />
reduction can he gained through the introduction of<br />
countermeasures into cuffent vehicle designs.<br />
Two main computer databases containing specific<br />
vehicle and occupant information on UK road accidents<br />
are available to the Vehiclc Inspectorate, one database<br />
focuscs mainly on Primary Safety (Accident Causation)<br />
and has data accumulating at a rate of approximatcly<br />
2000 accident/vchicle inspections per ycar on all vehicle<br />
lypes.<br />
The second database focuses on Secondary Safety<br />
(Injury Reduction) and has data accumulating at a rate of<br />
approximately 700 accidcnts/vehicle inspections per year<br />
mainly involving cars and more reccntly, light goods<br />
vehicles and minibuses. It is this lattcr database which is<br />
r36<br />
briefly described and analysed for the purposes of this<br />
paper.<br />
The UK Co-operative Crash Injury Study (CCIS)<br />
providing the information for this database was<br />
cstablished in the early 1980's and the methodology and<br />
organization of the study was reported in detail by G M<br />
Mackay et al in a 1985 SAE paper []. The study was<br />
originally established to investigate the mechanisms of<br />
occupant injuries in car accidents and to provide basic<br />
research data to assess the effectiveness of thc injury<br />
reducing featurcs of current EEC/ECE Dircctives and<br />
vchicle safety regulations. The Department's Transport<br />
and Road Rescarch Laboratory (TRRL) storcs all the<br />
data on thc vehicle examinations and occupant injuries<br />
on its mainframe computcr database. This database<br />
contains dctails of 370'7 vehiclcs involved in 3344<br />
accidcnts, and occupant casualties. This data is medical<br />
data on the 6236 analysed by TRRL, Birmingham University<br />
and Loughborough's Institute for Consumer<br />
Ergonomics for vchicle safety research purposes. An<br />
overview of the study with typical analysis was published<br />
by M Galer ct al in the proceedings of the l0th<br />
<strong>ESV</strong> conference [2].<br />
Crash Investigations by Vehicle fnspectorate<br />
Staff<br />
Data for the CCIS database is collected in a uniform<br />
manner by accident researchers from the two universities<br />
and by thc seven teams of Vchicle Inspectors from VL<br />
The accidents arc selected at random in accordance with<br />
agreed stratified sampling techniqucs in each of the 7<br />
study areas. In addition to collecting data for research<br />
purposes, the vehiclc cxaminers are traincd to detect any<br />
secondary safety concerns such as design or manufaclur*<br />
ing defects in the vchicle $ystems inspected. Such<br />
concerns are reported separately to VI headquarters on a<br />
vehicle safety defect report. Components such as scatbclts<br />
which have brokcn in light to medium frontal<br />
impacts will be photographed before being removcd fiom<br />
the vehicle. All such vehicle or component dcfccts are<br />
then investigated by VI in conjunction with the manufacturer<br />
to cstflblish the cause ol' the concern and<br />
whether a significant number of vchicles may be<br />
similarly affected. If this is the case vehicle recall action<br />
is the likely outcome.<br />
Identifying Secondary Safety Concerns<br />
In order to review intcrcsting cases both from an<br />
occupant injury point of view and to cxamine possible<br />
vehicle concerns, meetings are arratrged at tbur monthly<br />
intervals in which representatives from the University<br />
and VI accident investigation teilms present recent'-cases
of interest" for wider discussion amongst their accident<br />
research colleagues. Often at these meetings vehicle<br />
concerns are identified in which it is felt that some<br />
action could be taken to mitigate the injuries received by<br />
occupants in future similar crashes. Potential as well as<br />
actual vehicle injury concerns are also discussed as part<br />
of the *'cases<br />
of interest' session. For example a frontal<br />
impact accident in which the bonnet retaining hinges lost<br />
their intcgrity allowing the edge of the bonnet to penetrats<br />
the windscreen with potential or actual injuries<br />
would be discusscd. Accident Investigators would<br />
discuss the case in question and reflect on any similar<br />
cases that they may have seen. Where accidcnt cases<br />
identify a vehicle design concern or manufacturing<br />
concern which should bc corrected these are noted and<br />
subsequently the whole accident database is checked for<br />
similar concerns. Figure I shows the data fields currently<br />
extractcd by vI from the much larger data set of vehicle<br />
and occupant datfl. Although the numbcr of search fields<br />
is relatively small some useful data analysis can be<br />
carried out. In the vast majority of cases the vehicle<br />
safety concern is not of sufficient seriousness to justify<br />
formal vehicle recall action under the terms of the UK<br />
code of practice which dctails action to bc takcn whcn<br />
identifying a significant safety defect. Howevcr in these<br />
cases it may be considered that some action could be<br />
taken by the vehicle manufacturer to improve for the<br />
future, an occupant's chances ofavoiding injury from the<br />
concern identified. In the case idcntificd above<br />
concerning bonnet integrity, lhc nranulacturcr would be<br />
invited to examine the related cases and consider<br />
whether a more robust design or manufacturing arrangement<br />
may prevent a recurrence. Invariably when such<br />
modifications are implemented at an early stage within<br />
the life of the model concerned, real injury savings often<br />
result from modification of the vehicle or the<br />
manufacturing methods used to produce it.<br />
CASE NWBER: L0624 VEHICLE NiJl,lBER: I TA NTMBER: A 1580<br />
Vehlcle Make: VEHTCLE 'X'<br />
Mddelr ESTATE {O{5)<br />
Suffix/Prefix: A Case vehicler YES<br />
Impact type: FROMr Defect: VSD<br />
,t.l<br />
Nuhlf,er of OccupantBr 01<br />
OccupanE Injury Belted EjccEion<br />
2<br />
3<br />
I<br />
f<br />
6<br />
Fuel SyaLem Dffigc,/leakager Y Fronl s€al BeIt Problem:<br />
Vehicle caught Flre: N Rear Seat BeIt Prdblem:<br />
Hlndscreen ContJcted: N Child Restraiuts:<br />
Rear Door Opened: N Ejectect:<br />
Side Door Opened: N Ejected:<br />
Side G1ass Damagedr Y EjecLed:<br />
SEeerinq whee] cont.act€dt Y Load Presentr<br />
Front Seat Dasaged: Y Load Restraint Failed:<br />
Rear Seat Dmaged: N lnjuries l"rom Load:<br />
Figure 1. Shortform Data Coding ShBBt<br />
<strong>Section</strong> 3: Technlcal Sesslons<br />
Typical Database Analysis<br />
Two types of analysis of lhe database looking for<br />
vehicle concerns are carricd out, one involves the search<br />
for similar cascs in order to identify repeating concern$.<br />
The second is where an analysis of a more often<br />
obscrvcd concern needs to be compared to other<br />
manufacturcrs vchicles with similar style and weight<br />
classification. Examples of both types of analysis are<br />
detailed below to illustrate how real safety improyemcnts<br />
can be achieved.<br />
Case I<br />
Several cases of **""i, kncc or compound lower leg<br />
fractures were observed from mcdium cnergy frontal<br />
accidents in a popular European hatchback model. These<br />
accidents were all in the range 40-70 kph delta V rangc<br />
and none of the drivers received fatal injurics. Howcver,<br />
a common injury to each was the AIS 2 or 3 lowcr leg<br />
injuries caused by a brake pedal brackct asscnrbly which<br />
was forced through the heater ducting and facia cladding<br />
as a result of the impact forces and the rotationfll effect<br />
caused by the driver when applying heavy braking to the<br />
pedal prior to impact. Thc injurics received were<br />
typically open Tibea or Fibula fractures just below the<br />
knce caused by the forward edge of the pressed bracket<br />
which peclcd back whcn contact with the lower leg bone<br />
was madc. Accident investigators at the case review<br />
mectings confirmed that no othcr modcl types they were<br />
cxamining produced similar and consistent injuries which<br />
would have rcsultcd in such debilitating injuries.<br />
Research carried out in Sweden by Folksam on small car<br />
crashes also involving this model did not reveal an above<br />
average incidence of leg injury. However, it was<br />
subsequently discovered that thc lcft hand drive version<br />
of the pedal bracket was a diffcrcnt shape and protruded<br />
towards the drivers knee by ?0 mm less than on the RHD<br />
vcrsion. Similarly crash test using instrumented dummies<br />
to Ineasure femur loads also did not reveal this concern<br />
possibly because the forces applied to the brake pedal in<br />
panic braking were not being reproduced in the dummy<br />
tests and only LHD versions were tested. So we had a<br />
situation where UK real world accident research dala<br />
was showing a specific vehicle concern which was not<br />
evidcnt from extensive crash tcst by the manufacturer or<br />
front Swcdish insurance data involving only LHD<br />
variants of the vehicle.<br />
The vehicle fascia design was modified by the<br />
manufacturer as il result of the conccrn. A crash pad<br />
involving a shaped steel plate was riveted to the reverse<br />
.side of lhe fa.scia moulding around the underside of the<br />
steering colurnn. This was dcsigncd to spread the load of<br />
the pedal brackct against the knee and prevent its<br />
protrusion beyond the fascia cladding. To date wc hilve<br />
not observed similar severe leg injuries arising from the<br />
modified vehicle. Although this model is about to be<br />
superseded and the new model use$ the same pedal<br />
bracket ilssemblies as the old one. the bulkhcad dcsicn is<br />
r37
13th lnternatlonal Technlcal <strong>Conf</strong>erence on Experlmentel Setety Vehlcles<br />
significantly stiffer reducing the rearward movement<br />
effect of the bracket in an impact. The manufacturer has<br />
advised that this, combined with the new models use of<br />
a seat buckle activated pre-tensioning device should<br />
minimisc the problem in futurc similar accidents.<br />
Case 2<br />
Accident Investigators were seeing a higher than<br />
expected frequency of concern involving seat belt buckle<br />
casings which shattered as a result of the intrusion<br />
causcd by side impacts to a popular UK model of small<br />
hatchback car. The result of the side structure intrusion<br />
occasionally also caused the seat squab hinge to jam the<br />
seat belt release mechanism as a result of the upward<br />
movcmcnt of thc seat/floor pan caused by side structure<br />
intrusion. Data on about 15 cases of the concern had to<br />
be collected before a sufficiently robust case for action<br />
could be put to the vehicle manufacturer. This concern,<br />
because it was side impact related, was not addrcssed by<br />
any current or proposed regulation but was evident on<br />
about 97o of the side impact cases involving the modcl<br />
concerned.<br />
A major redesign of the vehicle structure was required<br />
to overcome the problem, this involved improvements Io<br />
the seat slides, floor pan and associated brackets which<br />
wsre strengthened. A substantial cross brace was added<br />
to significantly improve the side impact stiffness of the<br />
vehicle and a modified metal strap type of seat belt stalk<br />
was introduced to further reduce seat to buckle casing<br />
clashes. These modifications significantly rcduccd the<br />
possibility of entrapment fls a result of scat belt casing<br />
damage and consequential damage to the releitse<br />
mechanism.<br />
The previous two cases examined specific concerns<br />
with a model in which accident investigators and vehicle<br />
examiners considered that a problem existed with the<br />
vehiclc dcsign or construction which should be corrected.<br />
Often injurics and vehicle damage concerns need to be<br />
examined statistically in order to make comparisons of<br />
secondary safety system performance between different<br />
manufacturers models. Ideally a large database of<br />
information involving the modcls to bc compared is<br />
requircd. Variablcs such as direction of force at impact<br />
or impact severity (measured as delta V using crash 3<br />
computer programmc) can be used to refine the<br />
comparison of models in addition to the obvious one of<br />
comparing vehicles in the samc wcight/body<br />
classification. Thc following 3 cases illustrate how<br />
comparisons can reveal the models which have the<br />
poorest secondary safety performance.<br />
Case 3<br />
In this example the accident investigators and vchicle<br />
examiners were reviewing cases in which steering wheel<br />
hub covers were becoming displaced in impacts and the<br />
concern was that the exposed hub nut or sharp edges of<br />
the hub cover were causing excessive facial injuries. A<br />
138<br />
database analysis was carried out in which the model<br />
concerned was the focus of attention. By examining<br />
frontal impact accidents with belted drivcrs in which<br />
face/head injury through contact with the steering wheel<br />
was observed it was possible to see how thc model in<br />
question compared with others. Care was taken to ensure<br />
that the vehicles used for comparison were in the same<br />
weight/body classification as the subject vehicle and that<br />
a sufficient number of accident records were available<br />
for comparison.<br />
Table I shows the results of this comparison and it<br />
was observed that from more thfln 300 accidents<br />
involving Model A the highcst pcrccntagc of facial<br />
injuries at l1Vo was observed. The majority were AIS I<br />
(minor) injuries believed to be caused mainly from the<br />
hard finish two spokc steering wheel fitted to73% of the<br />
Model A variants. The manufacturer had alrcady taken<br />
steps to improve the product by fitting a "soft" feel<br />
wheel as standard. There are indications that this wheel<br />
is demonstrating useful injury rcductions over the<br />
standard "hard" $teering wheel. The manufacturer<br />
concerned was one of thc sponsors for the CCIS work<br />
and was clcarly awarc of the concern and took<br />
appropriate action at an early stage. This example<br />
demonstrates the uscfulness of manufacturers getting<br />
early injury information from a large numbcr of accidcnt<br />
cases involving their models.<br />
Table 1. Frontal lmpact Accidents-Belted Driver with<br />
Head/Face Contact on the Steering Wheel<br />
ModeI Accidents wiLh face/<br />
head injuries from<br />
steering wheel (t)<br />
Injury severity<br />
AIsl1AIs2lAIs3<br />
( * ) l ( * ) l ( * )<br />
Mode 1l 1l 3 1<br />
Mode B r.3 10 2<br />
Hode c 9 f, A 0<br />
Mode D 9 l 0<br />
tlodel E 6 0 0<br />
Model F 6 l 3 0<br />
Case 4<br />
This investigation commenced with a single case of a<br />
seat belt stalk which pulled out of the floor pan complete<br />
with fixing nut and space in a frontal (12 O'clock) 807o<br />
overlap accident with another vehicle. The delta V for<br />
the subject vehicle was estimated at 67 kph using crash<br />
3 and the drivers weight was 80 kgs. There was no rear<br />
occupant loading of the front seat. The manufacturer of<br />
the vehiclc provided information on l5 harrier impact<br />
tcsts carricd out on vehicles equipped with dummies at<br />
the standard impact speed of 48 kph and provitled seat<br />
bclt anchoragc test rcsults from 5 production bodyshclls.<br />
All results showed no failures and this single accident<br />
failure although very unusual was considered an isolated<br />
incident.
However a second similar incident involving the<br />
model in a 12 O'clock impacl with a heavy goods<br />
vehicle also produced a similar failure where the seat<br />
belt stalk complete with anchor bolt spacer and fixing<br />
nut pulled through the floor pan. In this case the driver$<br />
weight was 87 kg. The delta V at impact was computed<br />
at 46 kph using the crash 3 computer programme,<br />
although the manufacturers estimflte was about 54 kph<br />
with the crush profile being fairly evenly distributed<br />
across the front of the vehicle.<br />
The manufacturer again suggested that the higher than<br />
average weight of the drivcr was largely the cause of the<br />
failure. We carried out a database analysis of our<br />
database to idcntify any related cases. Peer group<br />
vehicles similar to the subject vehicle were also<br />
examined for the purposes of comparison. The search<br />
criteria used was ll, l2 or I O'clock front impacts with<br />
damage to the seat bclt mounting points observed. These<br />
were split into inboard, B pillar swivel and lower<br />
outboard anchorage damage. For each case the impact<br />
delta V, weight of occupant and any loading of the front<br />
seat belt from rear occupants or luggage was recorded.<br />
The results are shown in Table 2. The summary table<br />
shows the results for models of similar size and weiuht<br />
to the subject vehicle (Model A).<br />
Table 2. Inboard Anchorage Concsrns-Summaty Table<br />
Vehlcle<br />
!todel<br />
l,tddel A<br />
fiodel B<br />
l,iodel c<br />
Hodel D<br />
Number ln<br />
Sant)l e<br />
60<br />
551<br />
lnboard Anchor<br />
IJaruged Fa I I<br />
6<br />
3<br />
0<br />
z<br />
0<br />
0<br />
0<br />
B PllIar swlvel<br />
Damged Fa 1 I<br />
I O<br />
8 1<br />
10 0<br />
0 0<br />
Lowr Out -<br />
board Anchor<br />
Daroled Fa I I<br />
0 0<br />
6 0<br />
2 0<br />
The summary tablc shows that anchor point darnage<br />
was relativcly infrequent comparcd to each model sanrple<br />
size. Damage in some cases was due to direct conttct<br />
with an intruding vehicle and in other instances by the<br />
severity of thc accident. In some cases additional rear<br />
loading was imposed on the seat belt system. Model A<br />
had the worst record of inboard anchorage problems with<br />
2 suffering distortion damagc and two suffering complete<br />
loss of integrity, this was despite having the smallest<br />
sample size of the models examined.<br />
The manufacturers type approval and conformity test<br />
data showed that the original anchorage design cxceedcd<br />
the 27kn ECE R14 Regulation minimum load rcquircments<br />
by about 337o. However the later introduction of<br />
a thicker pile carpet into the model range meant that fl<br />
much dceper spflcer between the seat belt stalk and the<br />
floorpan was required. This imposed additional bcnding<br />
loads on the anchorage reducing the margin of acceptance<br />
to just lVo to l0Vo above the minimum type<br />
approval requirements. This slim margin was sufficient<br />
lo cause anchorage failures in real world accidents, a<br />
phenomenon pructically unknown on our accidents<br />
datrbase. Corrective action taken by the manufacturer<br />
Sectlon 3: Technlcal Sessions<br />
was to revert back to the original smaller spacer on the<br />
inboard anchorage.<br />
It was interesting to note on observing a typical<br />
manufacturers anchoragc test to destruction on a<br />
production vehicle that the floorpan deformation in the<br />
real world accidents prior to failure was neglible whereas<br />
the pull test in the laboratory produced quite significant<br />
floor pan deformation. This was a$ a result of the<br />
relatively slow load onset rate for typc approval tests<br />
compared with the real accident situation. These<br />
differences nray also explain why no test failures were<br />
observed in thc laboratory and this case illustrates the<br />
need for rcal world accident data to identify any cases of<br />
marginal design performance.<br />
Case 5<br />
With about 3Va of vehicle accidents a yeflr in thc UK<br />
resulting in fire, thc possibility of doing a useful<br />
make/model analysis using a databasc growing at 700<br />
accidcnt cirses per ycar would produce sorne unsound<br />
statistics even for the most popular models on the<br />
database. However, when we consider that the potcntial<br />
for a firc is signilicantly increased once the vehicles fuel<br />
system integrity is breached some useful analysis by<br />
make and model can be carried out fuel system disruption<br />
as a potential design concern.<br />
Our prirnary safety accidents database had indicated a<br />
possible high fire risk concern with one particular model<br />
and at about thc samc timc accident researchers and<br />
vehicle examiners were highlighting several cxamples of<br />
unexpected fuel systcm damagc with the same model at<br />
our regular casc revicw mcctings.<br />
Table 3. Fuel System Disruption<br />
Model No: IhpacLed No Suftering<br />
Dffiage/Leakage<br />
A E B<br />
Mode F 55 22 40<br />
I'lode 72<br />
Mode H 41 5<br />
Hode I 63 6<br />
Hdde .J 76 6 8<br />
A database analysis involving frontal impacts in which<br />
undcrbonnct fuel system damage and leakage was<br />
observed was undertaken in order to examinc if the<br />
subject model was at variance with other popular nrodels<br />
on the database. Vehicles from the same size and weight<br />
class and from smaller wcight classes with good<br />
representation on the database were chosen for<br />
comparison. Table 4 shows the results of the analysis.<br />
The subject model (Model F) clearly suffcrs from a high<br />
incidcncc of fuel systenl disruption in frontal accidcnts<br />
with 407a of the sample of seriously damaged vchicles<br />
suffering loss of fucl systcm intcgrity. The next worst<br />
modcl was Modcl H with jlst lLVo showing disruption<br />
but even this vchiclc was clcarly significantly better than<br />
the subject vehicle. The vehicle manulaclurcr took<br />
I39<br />
::<br />
1<br />
-
lSth lntemetlonel Technlcal conference on Experimentel sefety vehlcles<br />
several measures to improve the situation having<br />
identified from the accident case notes the reasons for<br />
the concern. New engine mountings to provide greater<br />
levels of mount integrity in moderate to severe crashes<br />
were introduced and fuel hose Iengths were increascd lo<br />
reduce the possibility of them pulling off when stretched<br />
due to engine movement. The clamps used to secure the<br />
hoses also were subject to research for a better design.<br />
One interesting fact to emerge from the analysis was that<br />
the fuel system disruption for the vehicle model which<br />
proccedcd the subject model was significantly better with<br />
just 8% showing damagc and lcakage. In this case the<br />
design had taken a retrograde step in terms of its<br />
potential for fuel system disruption and fire following<br />
collision. A cross check using UK Homc Office fire data<br />
for crash and collision using peer group vehicles for<br />
comparison and taking account of the model populations<br />
on the road also confirmed that the subject model was at<br />
least three times more likely to catch fire than average.<br />
Atthough this data was unable to specify the likely<br />
reasons for the fires the data did support the potential<br />
fire concern identified from the CCIS accident database.<br />
Table 4. Fuel System Dlsruptlon-Later ilanufactured<br />
Vehicles<br />
!,tode1 No: Impacted No: $uffering<br />
Damage/Leakage<br />
Model F<br />
Model G<br />
Model H<br />
Mddel r<br />
Model .I<br />
80<br />
90<br />
100<br />
722<br />
23<br />
11<br />
7<br />
A c t<br />
?8.8<br />
'1<br />
.8<br />
18.0<br />
7.O<br />
10 .7<br />
Monitoring the Effectiveness of<br />
Countermeflsures<br />
The above case histories show how vehicle secondary<br />
safety concerns in crashes can be revealed from this<br />
study. The nature of the indepth recording of vehiclc<br />
damage information on the hard copy enables an accutate<br />
assessment of the cause of many vchiclc concerns. When<br />
counlermeasures are introduced by the manufacturer,<br />
their effectiveness can also be monitored by a study<br />
which is continuous in its nature. Thus if we take Case<br />
5 in the above section as an example it is possible to<br />
Donald F. Huelke, Ph.D.<br />
University of Michigan<br />
Transportation Research Institute<br />
J. Vernon Roberts<br />
National Highway Traffic Safety<br />
Administration<br />
analyse a further data set involving more recently<br />
manufactured vehicles which have been modificd to<br />
improve their performance. Table I shows the results of<br />
such an exercise using the same models for comparison<br />
as the earlier analysis. This shows that the fucl systcm<br />
damage and leakage concerns relating to model "F* fell<br />
from 407a of the population involved in frontal impacts<br />
to around 287o. Thus a feedback loop on the effectiveness<br />
of countcrmeasures is established and the<br />
performance of ncw models or system dcsigns can be<br />
compared with earlier versions using real accident data.<br />
Concluding Remarks<br />
The case studies show how it is possible even with a<br />
limited sub set of data from a high quality accident<br />
database to identify vchiclc safcty conccrns. Thc carlicr<br />
in a models life that the concern can be identified and<br />
corrected the greater the injury saving potential. With<br />
models having lifespans of 6 years or more it is even<br />
possitrle to verify the effectiveness of the countermeasure<br />
in correcting the concern. Other accident studies in other<br />
countrics in which manufacturers examitre their own<br />
vehiclcs involvcd in crashes can provide useful data on<br />
specific concerns but thcsc studies will have difficulty in<br />
drawing any conclusions on how their model compares<br />
with other manufacturers equivalent vehicles. The CCIS<br />
study enables these comparisons to bc made and will<br />
concentratc the design efforts for improvement in areas<br />
where clear evidence indicates poor or marginal<br />
performance. The benefits to mirnufacturcrs in acccssing<br />
real accident data are clcar and vehicle occupants will<br />
also benefil from thc resulting safer designs.<br />
References<br />
I. MacKay, G M, M D Galer, S J Ashton and P D<br />
Thonras<br />
"The<br />
methodology of indcpth car crashes in<br />
Britain", SAE papcr 850856, 1985.<br />
2. Otubushin, Gater et al, "Crashed<br />
Vehicle Examination<br />
Techniques". SAE paper 860372, 1986.<br />
3. Gustafsson H, Hagg et al, "Folksam<br />
car model safety<br />
rating 1989-90" Stockholm 1989.<br />
4. Galer M, S Clark, G M MacKay and S J Ashton,<br />
"The<br />
causes of injury in car accidents-An overview<br />
of a major study currcnl.ly undcrway in Britain."<br />
lOth <strong>ESV</strong> <strong>Conf</strong>erence.<br />
sr.w.r9<br />
Air Bags in Crashes: Clinical Studies from Field Investigations<br />
140<br />
Jamie L. Moore<br />
University of Michigan<br />
Transportation Research Institute<br />
Abstract<br />
This paper documents field investigations of "air bag"<br />
crashes. A full range of crashes are presented including
fatalities, to high speed impact with survival, and minor<br />
injury crashes. Also detailed are the UMTRI and NHTSA<br />
investigative alcrt systcms. Most occupants sustained<br />
minor injuries. Those not wearing the 3-point restraint<br />
had more minor injuries, and the occurrence of higher<br />
level injuries (AIS >2) was found more often in the nonbelted.<br />
<strong>Int</strong>roduction<br />
The true test of any automotive safety device is in the<br />
real-world of motor vehicle crashes. Like all of the other<br />
safety features bclore it, the air bag was well tested in<br />
the laboratory, in simulated crashes, and in full scale<br />
barrier crashes. These engineering testing procedures<br />
showed the air bag to be an effective occupant injury<br />
countermeasure in certain crashes before the air hags<br />
were made available to the driving public. However,<br />
through invcstigation ofreal-world crashes in the various<br />
impact environments does the true effectiveness of the<br />
air bag, in terms of injury mitigation, become apparent.<br />
This is a report of a series of air bag deployments in<br />
passcnger car crashes and the injuries of the drivers.<br />
At the University of Michigan an "early alert" system<br />
was developed for notification of air bag deployments.<br />
In that the research was sponsored by Chrysler<br />
Corporation, Nissan Motor Company, Ltd., and Ford<br />
Motor Corporation, letters were sent to dcalcrships,<br />
private body repair shops, as well as selected salvage<br />
lots, to notify them of thc investigative program and to<br />
alert UMTRI pcrsonnel of any air bag deployments via<br />
an 800 toll-free telephone number. Additionally, a<br />
"Wanted" poster was also enclosed to draw their<br />
attention to the program (Fig. l). A similar "Wantcd"<br />
poster was distributed by the Michigan stiltc Police<br />
Accident Investigation Unit to all of the Michigan State<br />
Police Posts.<br />
Contacts were also made with the Michigan Sheriff's<br />
Departmcnts. All police agencies in the area of lhe<br />
University of Michigan were also alerted and several<br />
insurance companies cooperatcd with us by providing<br />
information on air bag equipped cars in crashes. As our<br />
toll free number bccame distributcd throughout the<br />
country, we reccivcd numerous calls from drivers or<br />
occupants who were involved in air bag collisions. To<br />
date over 1,300 calls have been received of itir bag crash<br />
deployments.<br />
For years NHTSA has sponsored crash investigation<br />
teams throughout the continental United States. Most<br />
rcccntly these five teams were alerted through the<br />
Accident Invcstigation Division of NHTSA to investigate<br />
air bag deploymcnts in their respective geographic area.<br />
NHTSA also has a 800 toll-free telephone number as<br />
part of their early alert notification system. In addition,<br />
some General Service Administration (GSA) cars were<br />
also part of the governmcnt air bag fleet and all drivers<br />
were told to notify NHTSA in case of a crash involving<br />
air bag deployment.<br />
Flgure 1. "Wanted' Poster<br />
Sectlon 3: Technicel Sessions<br />
WANTED!<br />
CFABHES lt{VoLvlNG ANY CAF3WITHI<br />
. atF 8AC5 .<br />
. MflATIC sUT BELTS .<br />
. ffiABffiLDER BELTE frORX) ,<br />
ffir A dfl,en#hmdh - o. iF.<br />
drH unlwdo' khE.^ r'{'rFddE.<br />
Iclrt-, t.eooae#;ifif<br />
. h..r *Hir rBu|h. cqrf laF$. 'npryl<br />
ll possible, quickly estmats damage!.<br />
DO NOT HESITATE TO CALL<br />
The NHTSA has also devclopcd and utilizcd a system<br />
for notification of air bag events of interest. Most<br />
typically these events involve a crash where the air bag<br />
deploycd. This system incorporates the voluntary<br />
participation of air bag vehicle manufacturers, insurance<br />
companies, policc agencies, crash investigators, and<br />
private owners. The NHTSA teams investigate about 50<br />
cases per year as part of the agency's Special Investigations<br />
program.<br />
Results<br />
It should be indicated at the onset that the air bag is<br />
not the polio vaccine for traffic medicine. Two cases<br />
exemplify this point.<br />
Case I (UM-2805-90) The impact in this collision was<br />
so severe thflt the crash was totally un-survivable for the<br />
driver.<br />
This 1990 Ford Taurus was traveling westbound on a<br />
4-lanc dividcd limitcd-access highway when the driver<br />
lost control, crosscd the center grassy rnedian, entered<br />
the eastbound lanes and was struck by a 1986 White<br />
Semi Tractor-Trailer. There was extensive damage to the<br />
front and left side of the Taurus (Fig. 2). The 22 ycar<br />
old nralc driver was wcaring thc 3-point restraint. The air<br />
bag deployed. On impact he continued forward and to<br />
the left whcrc his ncck contacted the intruding driver's<br />
door. Hc sustained a deep laceration to the antcrior left<br />
neck with partial decapitation. Also, he sustained a<br />
fractured left femur, an open fracture of the left titria and<br />
fibula and multiple lacerations and abrasions about the<br />
body. No autopsy was performed thus thc cxistence of<br />
any internal injuries arc not known. (MAIS 6).<br />
Case 2 (Ntll'SA NC-90-18) This is a fatal crash<br />
involving an air bag equipped 1989 Chrysler LeBaron.<br />
Thc LcBaron crossed the centerline lnd struck a 1984<br />
Buick LeSabre herd-ort (Fig. 3). Extreme intrusion<br />
prevented survival
13th lnternatlonal Technlcal <strong>Conf</strong>erence on Expertmentel Satety vehtctes<br />
Figure 2<br />
female driver. The driver of the Lesabre and a rear seat<br />
passenger<br />
also were killed. (MAIS 6).<br />
ffi<br />
k@ffi uu'<br />
Figure 3<br />
Obviously, not everyone can be saved in any type of<br />
crash, evcn when fully belted in an air bag car. However,<br />
there are a numbcr of true "success"<br />
stories, some of<br />
which are documented below. Cascs 3 through 9 involve<br />
drivers who wcrc using the 3-point restraint system.<br />
Cases 10 through l3 are unbelted drivcrs in crashes.<br />
The case below shows that air bags are fusigned to<br />
SUPPLEMENT the protet:tion of the l-point restraint.<br />
Air bags only activate once during an accident,<br />
therefore, only the belts can help restrain occupanls in<br />
multi p I e -impac t c o I li sio ns.<br />
Case 3 (UM-NAB-01-]) This was a violent crash; the<br />
air bag in the Infiniti car significantly reduced thc injury<br />
level, along with the 3-point restraint. A 197'7 Plymouth<br />
Gran Fury was traveling westbound; attempted a left turn<br />
in front of a 1990 Infiniti M30 that was traveling at an<br />
estimated specd of about 72 kmph. The two cars struck<br />
head-on. Aftcr impact, the M30 rotated clockwisc whilc<br />
r42<br />
the Plymouth rotated counterclockwise and the vehicles<br />
struck again; the left rear quarter pancl of the M30<br />
contacted the right rear quarter panel of thc Plymouth.<br />
The maximum crush to the front of the M30 was<br />
extensive, about 64 cm (Fig. 4). The left rear quarter<br />
panel was crushcd about 36 cm.<br />
Figure<br />
The air bag of the M30 deployed during the first crash<br />
sequence. The 3-point restrained drivcr sustaincd the<br />
following minor (AIS l) injuries: cervical and thoracic<br />
strain (impact force), contusions across the abdomcn and<br />
chest (3-point restraint), contusion left knee (lowcr<br />
instrument pancl), contusion right lower leg (center<br />
console trim piece), contusion right anterior forearm and<br />
abrasions (air bag) and first degree thermal burns to the<br />
top of his right hand (air bag gas). The two front seat<br />
occupants in thc Plynouth Gran Fury were not wearing<br />
their safcty belts and were seriously injured.<br />
The Lincoln Continental was the first American-made<br />
car to fcaturc an air bag as standard equipment for the<br />
drivcr and front right seat pilssenger, ln this case, both<br />
air bags deployed and both front seat occupiurts were<br />
wearing the 3-point rcstraints, providing maximum<br />
protection.<br />
Case 4 (UM-FMA-020) A t9E9 Toyota MR-Z crossed<br />
the centerline at a high rate of speed and struck the<br />
Contincntal head-on. The police estimated the pre-crash<br />
speed of thc MR-2 to bc l0-5 kmph and the Continental<br />
pre-crash speed of 43 kmph. Thc maximum crush to the<br />
front of the Continental was about 47 cm (Fig. 5). The<br />
two front seat passengers in the MR-Z were not wearing<br />
the 3-point restraint systcms and sustained very serious<br />
injuries.<br />
In the Continental both the driver's and passenger's<br />
air bags deployed. The 3I year old, malc drivcr (183 cm,<br />
68 kg) was wearing the 3-point restraint; he loaded the<br />
restraints, sustaining cervical and lumbar slrain (impact<br />
torcc), a laceration to his forehead (rear vicw mirror), a<br />
conlusion to his left knee (lowcr instrument panel) and
M Figure 5<br />
a contusion to his right knee (ash tray) (MAIS 1)' The 28<br />
V** "io male front iignt putt*nger (183 cm' 95 kg)' also<br />
wearlng thc 3-point'restrainr, sustained ccrvical and<br />
thoraci*c strain limpact force) and contusions to both<br />
t n"** (gto"* Uox; lUatS l)' A 25 year old male right<br />
fear seat passcnSer was wcaring thc 3'point restfaint<br />
$ystem did not sustain any injuries'<br />
"'success<br />
Case 5 (UM CCA-055) This is another story<br />
where the driYer benefited from the air bag and 3-point<br />
rest aint. This 1990 Plymouth Acclaim had been travel'<br />
;;;;" spccd of about 88 kmph in the far right lane on<br />
;; i;"" a'iuio"o highway behind a slow-moving ractorlraiter.<br />
As the Acclaim entered the left lane in order to<br />
p"-t, ,ttt scmi truck also entercd the left lane' The front<br />
"O* "t the Acclaim struck thc rcar ot thc trailcr' Thc<br />
Cimage to the front right of the Acclaim was very ext*ntiJl<br />
where the toii'um crush was about 85 cm<br />
(Fis. 6).<br />
Figure 6<br />
i"*d<br />
The 23 year old belted male driver (185 cm' 84 kg)<br />
continued iorward and to the right against the restrainls<br />
r"O *tt" deployed air hag' He sustained a contusion<br />
urio* his shouider from the shoulder portion of the belt,<br />
contusiOnstobrrthknees(lowerinstrumentpanel)<br />
multiplc lacerations to his right fingers and forearm<br />
a";;-; ccnter pancl or flying glass) and multiple abra-<br />
*ion* to his right upper arm (MAIS l)'<br />
Case 6 UW-ZSAS-\|)<br />
(CCA-056) A 1991 Davtona<br />
driven by a 19 year-old femalc wearing the 3-point<br />
iesrraints ran a yellow light and struck a left turning<br />
i-gTl fuoi 5000. rne front of the Daytona srruck thc<br />
right side of the Audi' Damage to the Daytona was<br />
*"od*.ut* with maximum crush of 4? cm' to the right<br />
f.o"t U"*p*r corner (Fig' 7)' The driver (168 cm' 52 kg)<br />
sustainedcontusionsofbothlegs(lowerinstrumcn<br />
panel). There were no injuries reported from drivcr<br />
ioading of the tethered type air bag'<br />
fi--i;*," "<br />
*<br />
f r"-<br />
Figure<br />
<strong>Section</strong> 3: Technicet Se$sion$<br />
dftHd*-;trF<br />
Case 7 (NHTSA CA-90-tB) A 1991 Ford LTD Crown<br />
Victoria, driven by a 34 ycnr-old lap-shoulder belted<br />
*"r- tiitl cm, 91 ke) was invglved--i1^an extremclv<br />
severe head-on grasri with s 1974 GMC 1500 series<br />
picf.up truck. The velocity change in-the t2 o'clock<br />
dircction was approximilt;ly 50 mph for each vehicle<br />
irie. gl. trre aii uag deployed''The sust;aincd a<br />
-driver<br />
ituJtur*o right patelia *ltn a l'5 inch laceration of the<br />
;i;h, kn** (*tnee nolstcr), a contusion of the anterior left<br />
sh"oulder, a mid chest contusion' and irn abdominal wall<br />
contusion(beltrestrflintsystcm),andpainoftheri<br />
hand (steeiing wheel rim/instrument panel)' MAIS 2<br />
ih*r*'or* no injurics rcported from contacting the air<br />
-of<br />
Uug t.titoint. The driver tttt pittup truck was dead at<br />
the scene-<br />
Case I (UM-CCA-037) h 1988 Dodge Diplomat'<br />
A.i"en by a rcstraincd 32 ycar old malc (180 cm' 8a kg)<br />
struck the lcft side of a tractor-trailer unit that had<br />
iurned left in front of the car' Damage was concentrated<br />
143
lSth lnternetlonel Technlcal Conterence on Experlmentel Safety Vehlcles<br />
Figure I<br />
about the right front of the Diplomat (Fie. 9). The air<br />
bag deployed. No facial or torso injuries were sustained.<br />
Heavy braking by the driver accounts for the right ankle<br />
sprain (MAIS l).<br />
Figure I<br />
Case I (PSU 09 066A) A 1989 Dodge Diplomat struck<br />
a 1990 Dodge Dynasty in the left front side (Fig. 10).<br />
The lap-shoulder belted driver of the Diplornat, a 23 year<br />
old male (183 cm,73.5 kg) sustained a right leg fracture<br />
from thc toc pan intrusion (AIS 2).<br />
In the case. below the female driver was not wearing<br />
the 3-ltoint restraint and appeared to he well protected<br />
by the air bag alone, silstdininE only minor iniuries. She<br />
refused medical assislante at the scene but voluntdrily<br />
went Io the emergency room a few hours aJier the<br />
collision.<br />
Case l0 (UM-CCA-035) At an intersection a 1983<br />
Chevrolet Camaro attcmpted to turn left in front of a<br />
1989 Chrysler LeBaron convertible that was traveling at<br />
about 48 kmph. Thc front of the LeBaron struck the right<br />
144<br />
Figure 10<br />
side of the Camaro. The damage to the front of the<br />
LeBaron was quite extensive whcrc thc maximum crush<br />
was about 44 cnr (Fig. ll). The 40 year old (168 cm, 89<br />
kg), unhelted female drivcr continued forward against the<br />
deployed air bag. She sustained the following AIS-l<br />
injurics: contusions and abrasions to her chest and<br />
forcarms (air bag), contusions to both knees (lower<br />
instrument panel), cervical strain (impact force), a<br />
laceration to thc top of her right foot (broken bottle)<br />
and a contusion to her right forearm possibly from<br />
contact with either air bag or the upper instrumcnt pancl<br />
(MA|S l).<br />
Figuro 11<br />
Case lI (UM-CCA-027) ln this crash the unbelted<br />
driver sustained a fractured right femur (MAIS 3) from<br />
impact with the lower instrument panel. The air bag<br />
provided excellent protection to his head and torso.<br />
A 1966 Whitc 9564 TD Wrecker was towing a L9'74<br />
Frcightlincr 6x4 Truck in front of a 1988 Chryslcr
LeBaron. Tte wrecker and Freightliner stopped waiting<br />
to make a left turn when the Chrysler struck the rear of<br />
the Freightlincr (the towed vehicle). The damage to the<br />
front of the LeBaron was quite extensivc with maximum<br />
crush about 58 cm. (Fig. l2). In addition to dflmage to<br />
the front bumper, grille assembly and hood, the left<br />
wheelbase was reduced about 8 cm. The 47 year old<br />
male (178 cm,72 kg), male driver sustained a fracturcd<br />
right femur (lower instrument panel), chin abrasion and<br />
chest contusion (air bag) and cervical strain (impact<br />
force) (MAIS 3).<br />
Flgure 12<br />
Case 12 (UM-CCA-036) (NHTSA CASI-S1) This is a<br />
multiple impact collision. The air bag deployed during<br />
the first crash scqucnce protecting the unbelted drivcr.<br />
The driver wa$ then ejected through the open left door<br />
prior to the second impact.<br />
A 1989 Daytona was traveling on a two lane suburban<br />
roadway. The driver reached down to insert a cassette<br />
tape and when he looked back to the road, he saw something<br />
in his travel lane. He steered to the right, downshiftcd<br />
and went off the roadway striking a bridge<br />
support pillar. The damage to the front of the car wils<br />
quite extensive wherc thc maximum crush was about 230<br />
cm. Thc total Delta V for the first impact was calculated<br />
at 96.9 kmph (Fig. 13). Following this irnpact, the<br />
Daytona rotated in a clockwise direction, spun off the<br />
support pillar, and continued in an casterly direction. Its<br />
lett door, which had opencd as a result of the first<br />
impact, subsequcntly $truck a second concrete pillar.<br />
Thc 24 year old male unrestrained driver (183 cm, 79<br />
kg) moved forward aglinst the deployed air bag at initial<br />
impact and then was ejected through the open left door.<br />
Becausc ot the ejection, it is unsure if all of his injuries<br />
were causcd by the first impact (steering whcel contact)<br />
or the ejection and impacting the pavement. He sustained<br />
the following injuries: Cerebral concussion,2-3 cm chin<br />
laceration, lip laceration, abrasions right sidc of his face,<br />
abrasions and contusions to the chest, abdomen, right<br />
Figure 13<br />
$ectlon 3: Technical Sessrons<br />
elbow and both feet. Also, he sustained a spleen<br />
laceration and a myocardial contusion (MAIS 4).<br />
We believc lhat his survival was due to the<br />
deploymcnt of the air bag in this extrcmcly high speed<br />
impact. Note the minimal injuries to the face and chcst<br />
where expected injurics of the facial bones and<br />
intrathoracic are nol found.<br />
Case l3 (U M-CCA-032) (NHTSA CA 89-45 ) The case<br />
below also involves an unbelted driver in a very severe<br />
crash where the air bag provided excellent protection to<br />
the driver's head and torso. The driver sustained multiple<br />
serious injuries to his lower extremities. (Details on the<br />
driver and his injuries were obtained from police and<br />
rescue personnel and thcrcforc are not complete).<br />
This 1989 Dodge Daytonir was westbound on a Z-lane<br />
roadway in a rural areil at a police estintated speed of<br />
129 kmph. The stolcn Daytona was being pursued by a<br />
police car. The Daytona was accelerating as it went into<br />
a curve in the road-As -the car continued to acceleratc it<br />
began to yaw out uf control, wcnl off the side of the<br />
roadway and slrqck a large tree stump. The car rotated<br />
counterclockwise around the stump and came to rest. The<br />
damage (130 cm clush) was concentrated to the front of<br />
the Dirytona (Fig. 14). Damage to the interior of the car<br />
was also extensive and thc occupant compartment<br />
intrusion was significant. The l8 ycar old male driver<br />
was not wearing the 3-point restraint. He sus[ained the<br />
following injuries: Arm fraclure, multiple contusions and<br />
multiple fructurc:i o[ the lower extremitics, two pelvis<br />
frrctures and an ankle fractulo (MAIS 9).<br />
Other Cases of <strong>Int</strong>erest<br />
Occasionally we found an air bag deployment case<br />
where thc driver/owner should have realized that there<br />
was a fault in the air bag systcm. Thc diagnostic module<br />
turns on the air bag warning light ior several seconds at<br />
ignition "on." If thcrc is a fault in the system this light<br />
will stly illuminated or flash in some pattern. Sotne<br />
145<br />
:r<br />
il<br />
I<br />
;l<br />
-1<br />
'.<br />
i<br />
i
lSth lnternatlonal rechnlcal conference on Experimental safety vehlcles<br />
Figure 14<br />
people ignored the light for several weeksor<br />
months<br />
before the air bag deployed in a situationwhere<br />
bag<br />
deployment would not hayc been expected.<br />
A. In one case the driver thought that the illuminated<br />
air bag light on the instrument panel was an indication<br />
that the ciu was equippcd with an air bag.<br />
B. In another unusual case thc air bag deployed at a<br />
relatively modest impact and thc owner/driver did<br />
not want to report this event to the insurancc<br />
c()mpany. Thereforc the owner repacked the bag into<br />
the steering wheel containcr and taped the air bag in<br />
place (UM-CCA-10).<br />
C. This 1990 Plymouth Sundance struck the rear end of<br />
a stopped 1989 Pontiac LeMans. The 6-5 year -old<br />
lap-shoulder beltcd female driver (163 cm, 72 kg)<br />
sustained an anterior neck abrasion (air bag) and a<br />
thermal burn to her hand (Figs. 15, 16). She worc<br />
gloves made of synlhetic matcrials that were melted<br />
in the area of the hand caused by escaping gasscs<br />
from the bag vent port on the back side of the bag<br />
(Fig. 17). The car bumper had been removed prior to<br />
the vehicle inspcction. Minor sheet metal damage<br />
was noted (Fie. l8) (UM-2854).<br />
Figure 16<br />
M<br />
Figure 17<br />
Figure 15 Figure 18<br />
146
Discussion<br />
From our studies of crashes involving air bag<br />
deployments it was notcd that approximately l9% of the<br />
97 occupants, in crashes investigated by the UMTRI<br />
team did not use thc available lap-shoulder belt rcstraint<br />
system at the time of the crash.<br />
Many of thc crashes were non-spectacular. In those<br />
whcrc the 3-point restraints were worn, injuries were at<br />
the AIS-1 level. Mainly the injuries were contusions to<br />
the knees and lower legs, contusions to thc abdomen,<br />
chest or shoulders from the 3-point restraints and<br />
cervical or lumbar strain.<br />
In those crashes where the 3-point restraints were not<br />
worn the damage profiles on many of the cars were<br />
similar to those where belts were worn. However. in<br />
these cases the unresfrained drivers also had primarily<br />
AIS-l level injuries but in each of these cases there were<br />
more AIS-l injuries and an occasional AIS-2 injury in a<br />
third of these drivcrs (Table l).<br />
Table 1. AlS, Alr Eag Deployment tnd Belt Restrelnt<br />
Usage<br />
With 3-Pt. Worn Without Belts Worn With Lap Belt Only<br />
Ats T;T-No--o. %<br />
0 9<br />
1 5 4<br />
e 10<br />
> 3 S<br />
12<br />
71<br />
13<br />
4<br />
0<br />
9 s 0<br />
7 3 9<br />
2 11<br />
0<br />
3 r00<br />
0<br />
0<br />
Field accident investigations and the data obtained are<br />
the only way to study thc actual effectiveness or the<br />
potential for air bag injury reduction. From the on-going<br />
investigations it is obvious that the air bag is providing<br />
its role as a supplement to seat belts for reducing facial<br />
impact severity with the steering assembly. Additionally,<br />
in highcr spccd crashes, it offers additional protection to<br />
the torso, head and neck. The data arc rclatively sparse<br />
on air bag deployments in other than non-frontal crashcs<br />
such as in rollovcrs, side impacts or rear-cnd crashes, or<br />
frontal crashes followed by other events such as spinout,<br />
a second car impact or rollover. Therefore the need for<br />
an on-going investigative program is obvious.<br />
Only through the accident inve$tigations can the<br />
"outliers"<br />
bc found, i.e., the unusual injury, the lifesaving<br />
bencfits of the air bag in high speed crashes, or<br />
the unusual or uncxpected events related to air bag<br />
deployment. In a number of cases there were facial<br />
erythema (redness) or abrasions due to the air bag<br />
deployment (Figs. l9-24). These illustrate thc worst of<br />
the minor facial injury cases that we have in the study to<br />
date. There have been a few cases of eye abrasions<br />
(corneal abrasion, sclera laceration) due to interilction<br />
with the air bag.<br />
Flgure 19<br />
Figure 20<br />
Figure 21<br />
Sectlon 3: Technlcal Sessions<br />
Most of the cars presented are manufactured by<br />
Chrysler Corp
Sth lntematlonel rechnlcal conference on Experlmentet satety vehlctes<br />
high speed crashes) cannot be directly studied by<br />
laboratory<br />
testing.<br />
Flgure 22 Flgure 23<br />
Flgure 24<br />
st.w.zr<br />
The Incidence of Multiple Injuries in<br />
Stephen Luchter<br />
Ruth Isenberg<br />
National Highway Traffic Safety<br />
Administration<br />
Abstract<br />
Multiple injuries are the norm in motor vehicle<br />
crashes, however, data on which injuries occur with<br />
which other injuries is limited. This paper idcntifies the<br />
most frequent injury combinations found in police<br />
rcported crashes in the early 1980's in the U.S.<br />
Specifically, the paper identifies thc five injuries with<br />
the highest incidcnce at each AIS level in thc National<br />
Accidcnt Sampling System (NASS) for the period l9[t2-<br />
1986. For each of these twenty five injurics, the fivs<br />
associated injuries with the highest incidencc are also<br />
identified. The results show that the five most frequent<br />
l4E<br />
In a study of the seating positions of drivers in<br />
simulated laboratory car cnvironments, Schneider found<br />
that the driver's chin can be as close as 240 mm to the<br />
steering-wheel hub under normal driving conditions (l).<br />
Additional forward movement of l.he driver's head may<br />
occur during a crash but prior to air bag deployment,<br />
particularly in low-speed impact near the lhrcshold of air<br />
bag sensor firing. Cases involving facial erythema or<br />
abrasion may thcrcfore occur when the face of the driver<br />
is less than 240 mm from the wheel hub at the time of<br />
facial interaction with the deploying air bag. Additionally<br />
bag leading edge velocity, whether at full pressurc or<br />
shear action developed when undcrgoing inflation, bag<br />
excursion, bag depth, bag denier, etc. may all play a role<br />
in the production of this type of minor injury.<br />
Reference<br />
I. Schncidcr, L.W., "Ergonomic<br />
Invcstigation of the<br />
Armrest Location in G', H- and S-Body Vehiclcs<br />
Using a Computer Controlled Univcrsal Seating<br />
Back." Final Rcpt. UMTRI-87-29, July, 1987.<br />
Motor Vehicle Crashes<br />
injuries comprise between one third and two thirds of the<br />
incidcnce of all of the injurics at thc various AIS levels.<br />
The results also show that, with a few exccptions, the<br />
incidencc of the most frequent associated injuries is in<br />
the rangc of 5 to l0Vo of the incidcnce of the most<br />
frequent injury. Thcsc results have important<br />
implications to the cstimation of the long tcrm<br />
consequenccs of motor vehicle injuries.<br />
<strong>Int</strong>roduction<br />
Each of the more than 3.7 million people injurcd cach<br />
year in police reportcd molor yehicle crashes in thc U.S.<br />
sustains an averagc of 2.5 injuries. Somc o[ these<br />
injuries have long terrn consequences, and our goal is to<br />
quantify thcse consequences at the national level.<br />
One unanswcred question is how thesc consequences<br />
are affected by the large number of mulliple injuries.<br />
This question is usually sidestepped and the effects of
the associated injuries are assumed to be included in the<br />
total costs or other impacts mcasured for thc most<br />
serious injury. One reason for this approximation is that<br />
over two thousand dilferent injuries have been identified<br />
in police reported crashes and the number of possible<br />
injury combinations is staggering.<br />
This paper focuses on solving a tractable portion of<br />
the problcm, identifying the most frcquent injury<br />
combinations. Once these have been idcntified, it will be<br />
possible to compare the consequences of thc most<br />
frequent injury as a single injury to the consequences of<br />
the most frequent injury in combination with the injuries<br />
associated with it.<br />
Background<br />
Multiple injuries are the norm in motor vehicle<br />
crashes, see Table I. This includcs people injured in<br />
police reported crashes (Luchter 1986, Luchter 1990),<br />
and emergency room (Peterson 1989) and trauma ccntcr<br />
parients (siegel et. al. 1989, siegel et. al. 1990) injured<br />
in motor vehicle crashes in the U.S. Multiple injurics in<br />
motor vehicle crashes have also been reported to be<br />
typical in Germany (Reidelbach and Zeidler, l9lt3,<br />
Zeidler et. al. 1989, Plctschen et. al. 1990) and Japan<br />
(Japan Research Center, 1986).<br />
Table 1. Overview of Multiple Inlury Literature<br />
Avtrtqe ilunbef<br />
1 llth of lnJurle,<br />
Hultlplr per lnJured Avftoa Hrr<br />
AdIq Tyle pt--Drlr I InJqrls surllvor ..0f Inl4E<br />
Ratdilbach & Hrnufrcturrr't 635 ilA L9 I I<br />
2eldler l!83 Rprordr, 80.83<br />
Luchtdr, l9E6 Pollte fteported 3a,5a2 S 2 3 NA<br />
lnJurle3 (N455)<br />
1982-r984<br />
Japrn Rereafch Insurrrce Eo7,mo i I E S<br />
t.nter l!86 llrlnt lgEl<br />
slegrl *t. al. rrruN Centtr 19? rA U l 5<br />
1969<br />
(Pelvlc Injurlltl<br />
Pstfron, 1989 [m€rtefcJ Rffi l,asa U 2,0 iA<br />
r 987-r 9EE<br />
Zrldlar at. tl Hofhnanrs 16,56a ll l l [A<br />
1969 lmpenertlon, l9B5<br />
Slegel pt. dl<br />
t990<br />
Tralma center<br />
(Brain lf,lured)<br />
I 983-l 986<br />
1,709 60 iA 1.,<br />
Luchhr 1990 Pollcp Ft0r)rted 64,618 55 il 2 5<br />
InJurlri (NAss)<br />
r9E?,r986<br />
Plettchci st tl Hefcedes Eenz 143 M U rA<br />
r 99q<br />
::r!pant!<br />
hrtil I ty<br />
Rrte, &rr.ll<br />
The average annual incidence of occupant and<br />
pcdestrian injuries in policc reported crashes in the U.S.<br />
during the period 1982-1986, disaggregated by body<br />
region, are shown below (Luchter, 1990). lntegumentary<br />
(skin) injuries to any body region are considered as if<br />
thcy were a separate body region since thcy comprise<br />
between a third and a half of the injuries to that regiott.<br />
The values are pcrccntages of injuries, not people<br />
injured.<br />
These data show that injuries to a pailicular body<br />
region are a significant part of all injuries when that<br />
body rcgion is the most severely injurcd regiort (MSIR).<br />
For example, for people whose most severe injury is to<br />
the head, 3l.6Vo of their injuries are head injuries,<br />
(L'7.lTo of which are single injuries), 50.59o a-re<br />
L4<br />
r5<br />
IE<br />
u<br />
t,t<br />
Sectlon 3: Technica/ Sessions<br />
integumentary injuries, and the remainder, l7.9Vo, arc<br />
injuries to other body regions. Although this approach<br />
provides insights into the overall injury mix by body<br />
region, it does not provide information on which injuries<br />
are associated with which other injuries.<br />
Injuriee % of Injuries to Body Region<br />
to Regie0<br />
l" ol<br />
When Beqion is MSIR<br />
Total Single Injuries to <strong>Int</strong>egum€fltary<br />
Body RegiAn Iniuries Iniuries Body Regign Iniuries<br />
Head 5.3 17.7<br />
Spine 13.0 37.6<br />
Lower Extremity 3.0 14.4<br />
Upp€r Extremity 4.0 21.2<br />
Abdomen 1.2 4.3<br />
Thorax<br />
Face<br />
2.S<br />
4.0<br />
8.8<br />
'l<br />
1 .7<br />
<strong>Int</strong>€gumentary 67.3 14.9<br />
31 .6<br />
56.8<br />
38.1<br />
39.5<br />
32.0<br />
s6.0<br />
41.8<br />
99.5<br />
50.5<br />
36.6<br />
48. I<br />
49.5<br />
43.9<br />
51.1<br />
56.6<br />
99.5<br />
A diagram illustrating thc overall mulliple injury<br />
relationship is shown in Figure I. The central circle<br />
represents an injury of interest. The other circles<br />
rcpresent the injuries associated with the injury of<br />
interest. The areas of the circles represent thc injury<br />
incidence, and the overlapping areas represcnt the<br />
incidencc of the associated injury when it occurs<br />
simultaneously with the injury of interest.<br />
Figure L Schematie Diagram of Multiple Inlurles<br />
AS$IAEO INJUFY E<br />
A number of different situations are possible. The<br />
total incidence of an as$ociated injury could be larger<br />
than the injury of interest incidence (Associatcd Injury<br />
P) or smaller (Associated Injuries Q, R, S, and T). An<br />
injury could bc associated with thc injury of intercst and<br />
with other associatcd injuries (Associatcd Injuries Q and<br />
R). Some portion of the incidence of any of thcse<br />
injuries could be a single injury (the non-intersect arcas)<br />
or an injury could not occur as a single injury<br />
(Associatcd Injury S).<br />
For each injury of interest, in this paper thc most<br />
frequent injurics at each AIS lcvel, (MFl), the paper<br />
discusses thc following:<br />
. The MFI incidcnce (the area of the central circle in<br />
Figure l).<br />
r49<br />
ii<br />
,t<br />
.:,<br />
n ,j:<br />
irj<br />
:<br />
r
1flth lnternatlonat rechntcat Gonference on Experlmental safety vehtcles<br />
. The injuries associated with the MFI and their<br />
incidence (the number of intersecting circles in<br />
Figure 1, their -'names",<br />
and their areas).<br />
. The multiple injury incidence (the intersect areas in<br />
Figure 1).<br />
. The single injury incidence (the non-intersect areas<br />
in Figure 1).<br />
Data<br />
Injury records on motor vehicle occupants involved in<br />
police reportcd motor vehicle crashes contained in the<br />
dala files of the National Accident Sampling System<br />
(NASS) for the years 1982-1986 form rhc basis for this<br />
study. During this period, NASS collected data on the<br />
injuries sustained by 64,698 motor vehicle occupants.<br />
The NASS file for the 1982-1986 period conrains<br />
about 400 data elcments describing vehicle and scene<br />
data for each crash, as well as dctailed injury information<br />
for up to six injuries per occupant. The injury data<br />
is obtained from autopsy rcports, hospital discharge<br />
summaries, emergency room reports and intervicw data.<br />
To obtain the data, full crash invcstigations are conducted<br />
by trained researchers, based on a statistical<br />
sample of police reported motor vehiclc crashes of all<br />
typcs and severities.<br />
The injury data in NASS are reported using the<br />
Occupant Injury Code (OIC), which is an extcnsion of<br />
lhc injury description found in the AIS (Abbreviatcd<br />
Injury Scale) dictionary (Association for thc Advancement<br />
of Automotive Mcdicine, 1980). Thc AIS description<br />
includes the injured body region, thc lesion, rhe<br />
organ affected, and the AIS severity level. The OIC adds<br />
the aspcct, that is, right, left, upper, lower, etc. This<br />
additional information is often important when dcveloping<br />
countermcasures.<br />
The time pcriod 1982-1986 represents a homogeneous<br />
data base, since the same basic sampling procedure and<br />
thc same ver$ion of the AIS dictionary were used lbr<br />
injury descriptions during the entire period. A major<br />
change was madc in NASS in 1987, with a new sampling<br />
scheme and the use of the lg85 version of the AIS. Data<br />
for 1987 are not complete. A cursory check of thc 1988<br />
data showed similar results to those reported here, but<br />
since the data bases are not fully compatible, thc more<br />
recent data were not analyzed.<br />
Results and Discussion<br />
The five years of NASS data (1982-1986), when<br />
extrapolated to the national level, represent about 13.5<br />
million occupants with ovcr 37 nrillion injurics. Eliminating<br />
thosc injuries where the body rcgion was not<br />
identified (130,000 cases), and those wherc the severity<br />
level was not identified (3.1 million cascs), there were<br />
an estimated 34 million injurics with a complcte injury<br />
description (NASS Occupant Injury Code (OIC)) during<br />
this period. This rcpresents an avcrage of 2.7 million<br />
occupants receiving 6.7 million injuries per year, or 2.5<br />
150<br />
known injuries per occupant. These occupflnts sustained<br />
2,130 uniquc injuries. The avcrflge annual injury<br />
incidence for motor vehicle occupants over the five ycar<br />
period by body region and severity level is summarizcd<br />
in Table ?. Body regions are as defined in NASS.<br />
Table 2. Annual Incidence of Motor Vehicle Occupant<br />
Inluries by Body Region<br />
BODI RIGIOI AI5 ] AI5 2<br />
PERCEilT 89.9 6.8<br />
SEVERITY LEVEL<br />
AIS 3 AI5 4<br />
ARH I 3t ,000 /,100 3,500 0<br />
BACI ]04,600 29,200 4.200 ls<br />
CNEIT 276,300 28,500 23,500 8,600<br />
ELgoH t8!,500 :,500 I .000 0<br />
FA[t ] ,4r 4, t00 4i.100 5,200 900<br />
HEAD sil,500 t3!,500 11,600 9.800<br />
ENrf 793,54t 25,800 5,600<br />
L0IER LEG 166,b00 20,100 t6, t00 0<br />
AB!0ilEN 69,100 t,300 r | ,400 9.500<br />
ilfr;E 525,500 19, r00 6,400 !00<br />
ilNoLE mDY 9t,900 600 200 r00<br />
lELvll.HIp 123,800 l!,00d t0, t00 300<br />
ANri-E-FmT t50,HOd 32,t00 7,300 0<br />
FoREARM t54,600 16,600 I,S00 0<br />
sf0!Lnr.R 266,100 38,000 6,800 0<br />
T[I[N ]cr,r00 3,800 18,600 200<br />
IRIIT HANb ll[,800 27,500 3,fl00 0<br />
UFPTR IXTREM]TY 5],OOO I ,9OO 100 0<br />
LoxEn EITREMITY 58,100 2,100 ldo 0<br />
2,4 0.4<br />
AIS 5<br />
0<br />
400<br />
I,000<br />
0<br />
0<br />
6,200<br />
0<br />
0<br />
4,600<br />
500<br />
300<br />
0<br />
t<br />
ToTAL 6"09t,800 457.J00 165,600 30,400 | 5,000<br />
0<br />
0<br />
0<br />
0<br />
AIS 6<br />
0<br />
rr.qoi<br />
0<br />
r, roi<br />
0<br />
;<br />
700<br />
500<br />
0<br />
16,7m 6,178,80d<br />
o,2<br />
IOTAL PERCEX]<br />
l4l,800 2,1<br />
338,500 5.0<br />
352,400 5.2<br />
t93,000 t.8<br />
r,4h?,500 2t.6<br />
771,800 il.4<br />
824,900 12.2<br />
l0?, /00 4,5<br />
106,000 L6<br />
653,100 9.6<br />
93,600 L4<br />
153,200 2.3<br />
190,300<br />
r /9, r00<br />
l|,500<br />
il4,700<br />
t68,t00<br />
59,200<br />
r. I<br />
2.8<br />
4.6<br />
3,2<br />
5.4<br />
0.9<br />
60,300 0,9<br />
xote: Vnluer rre annual average lncidence betyr€n 1982 {nd 1986 as shorn 1n tha ilASS fl te,<br />
ro{hded to the nearest 100. Annual ln4ld0ncs ldsr thsn 50 case, per year ara $horn rlth sn<br />
d9terirk. The body regloni af+ ar dcflncd li NASS,<br />
r IDtlderce ri! les! than 50 case, per ycir.<br />
The five most frequent injuries (MFI) at each AIS<br />
level f'rom I through -5 and their avcrage annual<br />
incidcnce ilre shown in Table 3. (AIl values have bcen<br />
roundcd to two significant figures). For cnch of thcsc 25<br />
injurics, the Table also shows the incidcnce expresscd as<br />
Table 3. Most Frequently Occurring Injuries by AIS Level<br />
InJ ury<br />
AI5 I<br />
Hhlplash<br />
Forehedd Contus I on<br />
Left Enee Contuslon<br />
Right Kree Contusion<br />
Forehead Laceratlon<br />
Subtotal<br />
AIS 2<br />
Concu s s ldn<br />
l.ef t Shoulder Fracture<br />
Rl ght Shoul der Fracture<br />
Rl ght Ankl e Frdcture<br />
Left Rib Fracture<br />
Subtotd I<br />
AIS 3<br />
Concusslon<br />
Left Fenur Fracture<br />
Rlght Femur Fracture<br />
Left Lower Leg Fracture<br />
Right I oter Leg Fracture<br />
Subtota I<br />
AIS 4<br />
Llver LacEratlon<br />
Concu!i ion<br />
5pl een RupturE<br />
LEft Rlb lra[ture<br />
Rlght Rlb Frdcture<br />
5ubtotal<br />
AIS 5<br />
Concusslon<br />
Ll ver Laceratldn<br />
Che5t nld VesJEl Lacerdtion<br />
Heart Lacefatlon<br />
Chest Blood Vessel Rupture<br />
5u btota I<br />
Total<br />
r Denotes less than 50 cases<br />
l'el ceil t<br />
Annual Percent oi Al5 5in9le Injufy<br />
Incldence of Total Level Incidence/X,<br />
6, t00,800 90<br />
s80,000<br />
3t 0.000<br />
26o, ooo<br />
250,000<br />
--?00 ,0r)t)<br />
I,600,000<br />
460.000 6<br />
120,000<br />
t 6 ,000<br />
1 5 .000<br />
1 5,000<br />
14.,000<br />
r 80,000<br />
r 66,000<br />
l0,000<br />
9,000<br />
9,000<br />
8,000<br />
7 .00Q<br />
43,000<br />
30,000<br />
3,600<br />
3,400<br />
3,100<br />
2,t00<br />
l_J00<br />
13,900<br />
1 5,000<br />
4,000<br />
I ,900<br />
I,500<br />
I ,300<br />
700<br />
9.400<br />
d . J<br />
4.6<br />
3.8<br />
1.1<br />
2.9<br />
?1<br />
r.8<br />
0.?<br />
0.?<br />
0.2<br />
0.t<br />
2.6<br />
2.4<br />
0.r5<br />
0.13<br />
0.13<br />
6.0<br />
5-4<br />
s.4<br />
0.r?<br />
a.-ta<br />
0. 63<br />
4.8<br />
4 .2<br />
25. 8<br />
0. 44<br />
9.5<br />
s.1<br />
260,000/45<br />
100,000132<br />
4.3 44,000ir7<br />
4.1 :r?,000/r3<br />
_-3.,.3<br />
26. 3<br />
36,ooo/rg<br />
26. r 7,400/06<br />
3, 5<br />
3,3<br />
800/05<br />
r,400/09<br />
3.3 l, 100/09<br />
-t-0<br />
:19. ?<br />
3,200/23<br />
0.05 I 1.8 *i 0l<br />
0.05 ll.0 100/03<br />
0.0s r0.? 200/06<br />
0.03 1.s */00<br />
s.-aQe s.0 otoo<br />
0.20 45.5<br />
0.22<br />
0.06 26.8<br />
0.03 r 3.0<br />
0,02 r0.?<br />
300/08<br />
0/00<br />
*t02<br />
0 ,02<br />
Q.0r<br />
0. r 4<br />
8.8<br />
4._7,<br />
63.5<br />
0/00<br />
* t02<br />
27.1<br />
200/02<br />
400/ 04<br />
?00/02<br />
r 00/0 r<br />
I 00/01
a percentage of the total injury incidence, and as a<br />
percentage of the incidence at the respective AIS level.<br />
In addition, the table shows the singlc injury incidence<br />
of each of the 25 injuries and that incidence expressed as<br />
a percentage of the total incidence for that injury. For<br />
example, there were 9,100 AIS 3 right femur fractures<br />
annually during this period. This represents 0.137o of all<br />
of rhe 6,800,800 total injuries, and 5.49vo of rhe 160,000<br />
AIS 3 injuries. Of these AIS 3 right femur fractures, 200<br />
occurred as a single injury, or 2.2Vo of all AIS 3 right<br />
femur fractures were singlc injuries.<br />
For each injury in Table 3, the five most frequently<br />
occurring associated injuries are shown in Tables 4<br />
through 8. In these tables, information relating to the<br />
MFI is shown in bold type. This includes the identity of<br />
the MFI, its incidence, the number of different injury<br />
types (other OIC's) associated with the MFI, and the<br />
number of associated injuries per 100 MFI. Here too, all<br />
values have been rounded to two significant figures.<br />
The remaining information in Tables 4 through 8<br />
concerns the five injuries associated with the MFI having<br />
the highest incidence. The tables show two values for the<br />
incidence for each of the associated injuries: the<br />
incidence when that particular injury is associated with<br />
the MFI, and the total incidence of the injury in the<br />
entire data base. In addition, for each of these five<br />
associated injuries, the Tables show:<br />
Teble 4. Five Iti,lost Frequent Associated Inlurlee<br />
for AIS 1 MFI<br />
HFI'/(l{umber of other oIC,s)<br />
AssoclrtEd InJury<br />
rhi plash/(674)<br />
Foreh€dd Contuslm/(583)<br />
s80,000 129<br />
AIS I Lower Eack straln<br />
AIS I Left Knee Contusldn<br />
AIS I Forehead Contuston<br />
AIS I Rlght Knee Contuslon<br />
AI5 I Upper Brck Straln<br />
65,000<br />
37 ,000<br />
37,000<br />
35,000<br />
Subtotal<br />
205 ,000<br />
310,ofi)<br />
Hhl plash<br />
37,000<br />
Rlght Kne6 Contusldn<br />
Left Knee ContUslon<br />
Forehead Abraslon<br />
Forehead Laceratlon<br />
Subtota I<br />
16 ,000<br />
36 .000<br />
30,000<br />
..t0.000<br />
1 59,000<br />
AI5<br />
AI5<br />
AI5<br />
At5<br />
AI5<br />
L€ft Knee Ctrtuslfl/(576)<br />
ATq Rlght Knee Contusloh<br />
AI5 Hhlpl ash<br />
AI5 Forehedd Contuslon<br />
AI5 Left la.nee Abraslon<br />
Ats ForEhead Ldceratlon<br />
Subtotal<br />
Rlght Knee Contuslon/(580)<br />
AIS Left F.nee contuslon<br />
Forehp16 6on,utton<br />
AI5 Hhl p1 i!h<br />
AI5 Rtght Knee Abraslon<br />
At5 For€head Laceratlon<br />
Subt otil<br />
forehead LrEcrrtld/(754)<br />
AIS Forehedd Contuslon<br />
Als ForEhead Abraslon<br />
AI5<br />
Ar5<br />
AI5<br />
Left Knee Contuslon<br />
Concus s I on<br />
Rlght Knee Contuslon<br />
5ubtota I<br />
'From Table 3<br />
260,000<br />
I 10,000<br />
37,000<br />
36,000<br />
r 7,000<br />
1 7.000<br />
217,000<br />
250,fi10<br />
I 10,000<br />
36,000<br />
35,000<br />
l 7,000<br />
2 1 4,000<br />
200,000<br />
20,000<br />
1 9 ,000<br />
I 6,000<br />
I 6,000<br />
I 6-000<br />
87.000<br />
As !oc Lnted. l'il.u.r_|l.s<br />
Per 100 1 of Total Assoc.<br />
l,lFI Assoclrtcd Total Hlth<br />
Injuries Hlth f,lFI Inrldence l,tFI, tr<br />
ll<br />
6<br />
6<br />
(<br />
34<br />
t68<br />
t2<br />
l2<br />
ll<br />
t0<br />
I<br />
228<br />
42.<br />
l4<br />
t4<br />
6<br />
_5<br />
243<br />
44<br />
l4<br />
t4<br />
_5<br />
o5<br />
224<br />
t0<br />
l0<br />
I<br />
8<br />
__E<br />
44<br />
9<br />
5<br />
5<br />
5<br />
_1l<br />
28<br />
1<br />
'l<br />
7<br />
6<br />
I<br />
3l<br />
I<br />
t8 6(1<br />
't8<br />
6<br />
6<br />
1<br />
I<br />
36<br />
4<br />
4<br />
4<br />
4<br />
.l<br />
20<br />
I 50,000<br />
?60,000<br />
31 0,000<br />
250.000<br />
5l,000<br />
sl(t,0m<br />
2 50 ,000<br />
2 60 ,000<br />
r ?0,000<br />
200,000<br />
250.000<br />
580,000<br />
31 0,000<br />
88 .000<br />
200.000<br />
260,000<br />
31 0,000<br />
580,000<br />
93,000<br />
200,000<br />
3 r 0,000<br />
I 20 ,000<br />
260.000<br />
I 20.000<br />
250,000<br />
43<br />
t4<br />
t2<br />
l4<br />
6l<br />
5<br />
la<br />
t4<br />
25<br />
t0<br />
44<br />
6<br />
l2<br />
r9<br />
I<br />
42<br />
l8<br />
8<br />
6<br />
l6<br />
t3 o<br />
Sectlon 3: Technlcal Sessions<br />
Teble 5. Flve Most Frequent Arsoclated <strong>Int</strong>urler<br />
for AIS 2 MFI<br />
HFI'l(iluf,ber of other OIC's)<br />
Associated<br />
InJury<br />
cmEUsslon/(766)<br />
Al5 1 Forehead Ldcoratlon<br />
AI5 I Hhlplash<br />
AIS I Forehead Contuslon<br />
AIS I Forehedd Abrasldn<br />
AIS I Rlqht Knee Contuslon<br />
Subtota l<br />
L Shoulder Fracture/(395)<br />
AI5 I L Shoulder Contuslon<br />
Al5 I LOnCUSt tOn<br />
AIS I Ler"t RJb Fracture<br />
AIS I L Shoulder Abraslon<br />
AIS 2 Left Rtb Fracture<br />
Subtota l<br />
R Shoulder Frrcturc/(378)<br />
AI5 2 Concusslon<br />
AI5 I Rlght Knee Abraslon<br />
AI5 I Rl ght Rl b Fracture<br />
AI5 I R Shoulder Contuslon<br />
AIS I R Shoulder Abrailon<br />
Subtota l<br />
Rlght Ankle Fricture/(341 )<br />
AI5 I Forehearj Laceratlon<br />
AI5 2 Concusslon<br />
AI5 I LoHr Fnce Laceratlon<br />
AI5 I Rlght Knee Abraslon<br />
AI5 I ForehPad Abraslon<br />
Subtotal<br />
Left Rlb Fricture/(343)<br />
AI5 I Hhtplash<br />
AI5 I LoHer Face Contuslon<br />
Al5 2 L :ihoulder Fracture<br />
AIS 3 Left Lung contusldn<br />
AI5 2 Rlqht Rlb Fracture<br />
Subtota l<br />
rFrfl Table l<br />
HFI'/(t{unber of oth?r oIC,s)<br />
Assoclrted InJury<br />
Concuss I on,/ ( 383)<br />
122.000 3e5<br />
r 6, fi)o 326<br />
Assoclated Inrlurles<br />
Per lfl) 1 of Total Asstr.<br />
HFI Assoclated Tdtal Htth<br />
InJIries Hlth ilFI lncldente f{FI,1<br />
18,000 15 4<br />
17,000 14 4<br />
15,000 l2 4<br />
10,000 8 2<br />
9,000 J ]<br />
69,000 56 l 5<br />
1,500 l0<br />
| ,500<br />
I ,300<br />
I ,200<br />
rl .100<br />
6,600<br />
9<br />
8<br />
7<br />
_7<br />
4l<br />
15,m0 3t5<br />
I,800 13 1<br />
r,zoo I 3<br />
I,100 I 2<br />
r,000 1 2<br />
_900 _n J<br />
6,000 42 13<br />
r4,0(n 276<br />
I ,900<br />
I,?00<br />
I,000<br />
I,000<br />
__ 99!<br />
5,900<br />
| 4,000<br />
I ,900<br />
I ,700<br />
I ,300<br />
l,000<br />
1.000<br />
6,900<br />
13 5<br />
8 3<br />
7 2<br />
7 2<br />
_ 5 J<br />
4l 14<br />
271<br />
1 4 5<br />
1 2 4<br />
l0 1<br />
7 t<br />
f f<br />
50 l8<br />
17 4<br />
r0 3<br />
l0 2<br />
9 2<br />
_ 9 ]<br />
55 ll<br />
il4<br />
200,000<br />
580,000<br />
3r 0,000<br />
r ?0,000<br />
250,000<br />
3 89,000<br />
3<br />
3<br />
2<br />
J.<br />
l3<br />
l ?0,000<br />
22 ,000<br />
24,000<br />
14,000<br />
3<br />
3<br />
J l3<br />
r 20,000<br />
e3,000<br />
20,000<br />
61,000<br />
22,000<br />
200,000<br />
r 20,000<br />
I 40,000<br />
93,000<br />
i 20.000<br />
580,000<br />
54 ,000<br />
I 6 ,000<br />
5,300<br />
7,300<br />
Table 6. Flve Moet Frequent Associated Inluries<br />
for AIS 3 MFI<br />
AI5<br />
AI5<br />
AIS<br />
AI5<br />
AI5<br />
Sub<br />
Forehead Lrceratlon<br />
Forehead Contuslon<br />
lorehead Abraslon<br />
I orr Fate Ldceratlon<br />
Hhlplash<br />
tota l<br />
Left Femr Fracture/(435)<br />
AISSRFenurFracture<br />
AIS I L LoHer Leg Frrcture<br />
AIS I Forehead Lacerrtton<br />
AIS 2 Conrusston<br />
AI5 ? L Lorer LEg tracture<br />
Subtota l<br />
0<br />
3<br />
I<br />
l9<br />
l4<br />
AstOCldted lnlurles<br />
Per 100 X, of Total Assoc.<br />
l'lFI Assoclated Total Hlth<br />
InJurles Nl th MFI Incldence HFI, 1<br />
10,000 395<br />
I ,700<br />
I,000<br />
| ,000<br />
900<br />
900<br />
5,500<br />
9.300<br />
I,000<br />
I ,000<br />
I.000<br />
700<br />
600<br />
4. 100<br />
Rlght Fexr Frrcture/(402) 9.lOO<br />
AIS 3 Left Fenur Fracture<br />
AI5 I Forehead fracture<br />
AIS 2 h Lower Leg Fracture<br />
AI5 2 Cotcu5r,on<br />
AI5 3 R LoHer [e9 Fracture<br />
Subtotal<br />
L Lftr Leg Frncture/(3O4)<br />
AIS 2 Left Ankle Fracture<br />
AI5 3 R Lorer Leg Frarturo<br />
AIS Z L Lower Leg Fractrrre<br />
AI5 3 Left Femur Frdctur e<br />
AI5 Z Cof,cusslon<br />
Subtotal<br />
R LdBr Leg Fracture/(286)<br />
AI5 3 l. LoYer Leg Frarture<br />
AI5 I Rlqht Femur Fracture<br />
AI5 2 RJght Ankle FractUre<br />
AIJ I LOnfUSStOn<br />
AIS I forehend Laceratlon.<br />
rFrm Table 3<br />
r "000<br />
900<br />
900<br />
800<br />
_ 800<br />
4,400<br />
8"500<br />
700<br />
100<br />
700<br />
700<br />
_ 40!<br />
3, t00<br />
7,2@<br />
700<br />
600<br />
500<br />
500<br />
400<br />
1,700<br />
350<br />
r2 I<br />
ro 3<br />
9 3<br />
9 2<br />
_ 9 ]<br />
49 l3<br />
221<br />
9 4<br />
9 4<br />
8 4<br />
8 4<br />
- 5 J<br />
l9 l8<br />
253<br />
9 4<br />
8 3<br />
7 1<br />
6 2<br />
l ]<br />
35 14<br />
200,000<br />
3l 0,000<br />
r 20,000<br />
1 40,000<br />
580, oo0<br />
9,000<br />
8.000<br />
200 ,000<br />
I 20,000<br />
8,700<br />
9,300<br />
200,000<br />
I,000<br />
I 20, ooo<br />
7,?00<br />
1 4,000<br />
7 rn6<br />
8, 700<br />
9, 300<br />
I 20.000<br />
8,500<br />
9, 100<br />
I 4,ooo<br />
I ?0,000<br />
200,000<br />
I<br />
0 II<br />
0<br />
5<br />
l0<br />
8<br />
I<br />
0<br />
I<br />
6<br />
I<br />
0<br />
0
13th lnternatlonal Technlcal <strong>Conf</strong>erenee on Experlmental Safety Vehlcles<br />
Tabh 7. Flw tbst Frequent Aesoclated Infurles<br />
for AIS 4 MFI<br />
flFI*/(Number of other oIC's)<br />
Assoclated InJury<br />
Llver Laceratlon/(281 )<br />
AI5<br />
AI5<br />
AI5<br />
AI5<br />
AI5 2 Ri ght Rl b Fracture<br />
Subtota I<br />
Coftruss lon/ (234)<br />
AT5<br />
AI5<br />
AI5<br />
At5<br />
AI5<br />
Spleen Ldceratlon<br />
Bl d Vessel Lacratlon<br />
Rlght Lung Contuslon<br />
Left Lung Contusion<br />
Forehead Ldceratlon<br />
Lowr Face Laceratlon<br />
R Face Lacerdtlon<br />
R Ldwer Leg Fracture<br />
Forehead Contuslon<br />
otdl<br />
SDleen Rupture/(255)<br />
AIS Hhdle Body Cdntuslon<br />
Concuss I on<br />
Left Lung Cdntuslon<br />
AI5 Hhle Body Laceratlon<br />
ATq Llver Rupture<br />
tal<br />
Left Rlb Fracture/(224)<br />
AIS<br />
AIS<br />
LEft Lung Contuslon<br />
R1 ght Rl b Fracture<br />
AI5<br />
AI5<br />
5pl een Laceratlon<br />
Ll ver Laceratlon<br />
AI5 L 5houl dEr Fracture<br />
5ubtotal<br />
Rlght Rlb Fracture/(185)<br />
_- - _.._-___llloc_lnled_ InlurIes<br />
Per 100 1 of Total fia.<br />
l4FI Assoclated Total Hlth<br />
IhJurles lll th MFI Incldence MFI, 1<br />
3,600 430<br />
I,000 27<br />
500 13<br />
400 l0<br />
too 9<br />
l_o.Q I<br />
2,500 68<br />
3,400 346<br />
400 13<br />
200 7<br />
200 7<br />
200 1<br />
_?00 J<br />
I,200 4l<br />
3, t00 18il<br />
400 12<br />
300 8<br />
2oo 8<br />
200 7<br />
I ,300 42<br />
2,300 479<br />
600 24<br />
400<br />
300<br />
300<br />
16<br />
13<br />
13<br />
3OQ<br />
I,900<br />
IE<br />
78<br />
r,soo 468<br />
AIS 4 Left Rlb Fracture 400 24<br />
AIS 4 Li ver Lacefatlon 300 19<br />
AI5 5 L1 ver Laceratlon<br />
Al5 5 Bld Vessel Lacratlon<br />
AIS 6 Bld Vessel Severence<br />
300 l8<br />
200 16<br />
_-aa.o 16<br />
I,400 93<br />
rFrffi Table 3<br />
?00<br />
?00<br />
I ,300<br />
I,900<br />
400<br />
300<br />
300<br />
300<br />
_ zQa<br />
I ,500<br />
I,500<br />
400<br />
300<br />
300<br />
200<br />
_2_00<br />
I ,400<br />
200,000 0<br />
140,000 0<br />
28,000 I<br />
7 ,200 3<br />
310.000 0<br />
5 2 20,000 I<br />
-5 _? ?8,ooo I<br />
33 ll<br />
469<br />
20<br />
l6<br />
l?<br />
80<br />
410<br />
|,3(x) 330<br />
300<br />
300<br />
300<br />
300<br />
200<br />
I ,400<br />
6 2,400 40<br />
3 r ,500 30<br />
? 4,800 7<br />
2 5,300 6<br />
] 7,300 4<br />
l5<br />
{<br />
7<br />
l2<br />
3 57,000 I<br />
2 120,000 0<br />
2 5,300 4<br />
2 5,500 4<br />
J 500 40<br />
ll<br />
5 5,300 l 0<br />
3 | ,500 24<br />
3 2,400 12<br />
3 3,600 I<br />
_l 16,000 2<br />
l6<br />
5 I,500 24<br />
4 3,600 I<br />
4 1,900 15<br />
4 1,500 16<br />
_3 I,100 zz<br />
20<br />
Table 8. Five ifost Frsquent Associated Injuriee<br />
for AIS 5 MFI<br />
HFIr/(ilunber of 0ther OIC'3)<br />
A5sdclated InJurY<br />
Concuss lon/ ( 302)<br />
AIS I Forehead Laceratlon<br />
AIS I Lovr Face Laceratldn<br />
AIS 2 Left Ankle Fracture<br />
AIS I Right Rib Fracture<br />
AISlRHoadLateratlon<br />
SIbtota I<br />
LlYer Laceratlon/(I93)<br />
AIS 5 Bld vessel Lacratlon<br />
AI5 5 Heart Lnceratlon<br />
AI5 3 Spleen Laceratlon<br />
AI5 4 Riqht Rlb Tracture<br />
AI5 4 Left Rlb Fracture<br />
Subtotal<br />
Chest Bld Vessel<br />
Laceration/(175)<br />
AI5 4 Llver Lnceratlon<br />
AIs 5 Llver Ldceratlon<br />
AIS 5 Heart Laceratlon<br />
AIS 4 Riqht Rlb Fracture<br />
AI5 3 5pl een Laceratlon<br />
Subtotal<br />
Heart Lrceratloh/( 106)<br />
AT5 6 Bld Vessel sevEronce<br />
AI5 4 Llver Laceratlon<br />
AI5 5 Llver Laceratlon<br />
AI5 5 Bld Ve55el Lacratlon<br />
AI5 4 Heart Laceratlon<br />
5u btot a I<br />
chest Bld vessl Ruptre/(82)<br />
AIS 3 Left Fenrur Fractilte<br />
AIS 6 Chest crush<br />
AIS 2 Right Knee Fracture<br />
AIS3Rl.unqLaceratton<br />
AIS 3 Left Lung Laceratldn<br />
rFrdm Table 3<br />
r52<br />
4,000<br />
A s soc I d t e d-l-L1!-Ll3l--<br />
Per 100 7. of Total Assoc-<br />
MFI Assoclated Total Hlth<br />
Injurles Hlth MFI Incldence t'lFI ' 1<br />
344<br />
ll 3 200,000 0<br />
2 0 0 6 2 1 4 0 , 0 0 0 0<br />
200 6 2 l4,oo0 I<br />
700<br />
200<br />
100<br />
100<br />
r00<br />
_LAq<br />
600<br />
2A<br />
20<br />
l7<br />
l4<br />
14<br />
93<br />
21<br />
z4<br />
z1<br />
t5<br />
ll2<br />
382<br />
23<br />
l8<br />
l8<br />
18<br />
1.0<br />
4 I,500 27<br />
4 1,300 23<br />
3 2,400 12<br />
3 I,500 20<br />
I 2,300 e<br />
l7<br />
7<br />
4 3<br />
I<br />
7<br />
34<br />
6<br />
I<br />
26<br />
3,600<br />
I ,900<br />
r,t00<br />
I ,500<br />
2 ,400<br />
I ,100<br />
3,600<br />
I ,900<br />
1 ,500<br />
700<br />
9, 300<br />
'| ,800<br />
4,600<br />
500<br />
100<br />
ll<br />
l6<br />
23<br />
l1<br />
6<br />
21<br />
6<br />
l6<br />
?0<br />
28<br />
2 5z<br />
20<br />
l4<br />
. the frequency of the associated injury expressed as<br />
the number of occurrences per 100 cases of the MFI,<br />
. the percentage of the associated injury incidence<br />
relative to the total incidence of all injuries<br />
associated with the MFI.<br />
. the percentage of the total incidence of a particular<br />
injury when that injury is associated with the MFI.<br />
For example, consider again the AIS 3 right femur<br />
fracture MFI (see Table 6). Associated with this injury<br />
were 402 other injuries, with a total incidence of 33,000<br />
(9,100 x 3.6). The fifth most frequcnt of thesc 402<br />
injuries was an AIS 3 right lower leg fracture, which<br />
occurred 800 times in comhination with the AIS 3 right<br />
femur fracture. These 800 cases represent 8.8 AIS 3 right<br />
lower leg fracturcs for each 100 cases of the AIS 3 right<br />
femur fracture. These 800 represenr2.4Vo of the 33,000<br />
injuries associated with the MFI. As part of the<br />
6,800,000 total injuries, there were 7,?00 AIS 3 right<br />
lowcr lcg fractures. The 800 of these AIS 3 right lowcr<br />
leg fractures associated with the AIS 3 Right Fcmur<br />
Fracture represent ll.IVo of all of the AIS 3 right lower<br />
lcg fractures.<br />
Other results show how the multiple injury characteristics<br />
vary with AIS level (Table 9), the associated<br />
injuries that occurred frequently per 100 MFI (Table I0),<br />
and thc injuries that had a largc part of their total<br />
incidence associated with a particular MFI (Table 1l).<br />
Table I. Overview of Multiple Infury Characteristlcs of<br />
Most Frequent Inluriee<br />
,lil, -.''<br />
kstrritedornru,le, Fr *.0;:,0[,?'.'<br />
91,;1,l: ilr,B,ill::i:l:l iljilt;i .".<br />
trlqhrd r".- H"1sl;id A" t'ii'lli ^tlo, AIstr Al!03 ^Iso4 AIs05 AIs05<br />
,,9-1*<br />
,l"lEis<br />
i rll iil,sll :il lll.il! i;iii 'i i i 3 ! !<br />
i ctt 346-458 !44 185-281 l2(l) 6 3 6 3 3 I<br />
; iii l+i-+iq 216 8!-30? 2l(?) 4 2 4 I s 2<br />
. vrrues In parenthpe€r rrt the numb€r of HFI InJufles thit rlto are assoclated Jnlurl"'<br />
Table 10- Associated lnluries with High Incidence<br />
per 100 MFI<br />
AisocI rted InJury<br />
AIS<br />
AI5<br />
AI5<br />
AI5<br />
At5<br />
AI5<br />
Als<br />
AI5<br />
AIS<br />
Rlght Kfree Contusion<br />
Left Knee Contuslon<br />
5pleefr Laceratton<br />
Left Lung Contu5lon<br />
Ieft Rib Fracture<br />
Llver Ldseratlon<br />
Elood Vess€l Sevetence<br />
L1ve. Laceratlon<br />
Liver Lateratlon<br />
Blmd Vessel Laceratlon<br />
iIFI<br />
AI5 | Left Knee Contuslon<br />
AI5 I Rlght Knee Contuslon<br />
Al5 4 L1 ver Laceratlon<br />
AI5 4 Left Bi b Fr'iciure<br />
AI5 4 Rlqht Rlb Frdcture<br />
AI5 5 Che5t Rld Versel Laceratlon<br />
AI5 5 Hoart Lasefatlon<br />
AIS 5 Heart Laceratlon.<br />
AI5 5 Heart Liceratton-<br />
AI5 5 Heart Laceration<br />
I nc I dence<br />
per 100<br />
M[I<br />
4l<br />
43<br />
z4<br />
24<br />
28<br />
z7<br />
?q<br />
z4<br />
2l<br />
Table 11. Associated Inluries with High Percentege<br />
of the Totsl lncidence<br />
AEsociated Injury<br />
AI5<br />
AIS<br />
AI5<br />
AIS<br />
AIS<br />
AI5<br />
AIS<br />
AIS<br />
AIS<br />
AIS<br />
AI5<br />
ATq<br />
AI5<br />
AI5<br />
AI5<br />
AIS<br />
Lower Eack Stralh<br />
Upper Bnck Stral n<br />
Right KDee Contuslon<br />
Left Knee Contuslon<br />
Spleen Lacefation<br />
Blood Vessel LacEratlon<br />
Li ver Rupture<br />
Rlght Rlb Fracture<br />
Left Rib Fracture<br />
Blood Vessel SEverence<br />
Blood Vessel Lateratlon<br />
Heart Laceratlon<br />
Heart Laceration<br />
Blood Vesssel Severence<br />
Heart Lacerdtlon<br />
Ri ght Lung Laceratlon<br />
AIS<br />
AI5<br />
AI5<br />
AI5<br />
AI5<br />
AIS<br />
AI5<br />
AI5<br />
AIS<br />
At5<br />
AIS<br />
AIS<br />
AIS<br />
AIS<br />
AIS<br />
AIS<br />
HFI 1. OF<br />
TOTAT<br />
Hhl pl ash<br />
44<br />
Hhlplash 60<br />
Left KnEe Contuslon 43<br />
Rlqht Knee Contulton 40<br />
Llver Laceration 40<br />
Ll ver Laceration 30<br />
Spl een Ruptufe 44<br />
Left Rlh Fracture 24<br />
Rlght Rlb Fracturo 24<br />
Rlght Rlb Fracture 22<br />
Ll ver Lacerdtion 25<br />
Llver l.aceration<br />
24<br />
Chest Bld Vssel Laceratlon 20<br />
Heart Laceratlon<br />
3l<br />
Heart Laceration 30<br />
Chest Elood Vessel Rupture 26
Applying the method to only the five most frequent<br />
injuries at each AIS level was necessary to simplify the<br />
analysis. It does, however, provide considerable insight<br />
into the overall motor vehicle injury problem. At the AIS<br />
I and 3 levels the incidence of the five most frequent<br />
injuries is more than a quarter of the total incidence at<br />
those levels. At the AIS 2 and 4 lcvels. this rises to<br />
almost half, and at the AIS 5 level to nearly two thirds<br />
of the total incidence at that level.<br />
With a few exceptions, multiple injuries are the norm.<br />
For l9 of the 25 MFI, the singlc injury incidcnce is 97o<br />
or less of the overall MFI incidence. For 14 of these 19.<br />
the single injury incidence is 5To or less of the ovcrall<br />
MFI. At the AIS I level, single injuries range from l3 to<br />
44Vo of the MFI total incidence, and for onc frequent<br />
AIS 2 injury there is a 23Vo singlc injury incidence.<br />
There are an average of 1.3 to 4.7 associated injurics<br />
per MFI. The number of associated injuries pcr MFI<br />
increases as thc AIS level increase from I to 4, with a<br />
slight decrease between the AIS 4 and AIS 5 levels.<br />
There are from 82 to 754 different injuries associated<br />
with the twenty five primary injuries. As the AIS level<br />
increases, there are fcwcr different injuries associated<br />
with each primary injury (fewer OIC's). The incidence<br />
of the most frequent associated injuries ranges from<br />
I.SVI of the total associated injury incidence for the<br />
pailicular MFI (AIS I Right Face Laceration associated<br />
with AIS 5 concussion), to 17.8% (for the AIS I knee<br />
contusion associated with a contusion of the other knee).<br />
The combined incidence of the five most frequent<br />
associated injuries ranges from 9.6Vo (associated with<br />
AIS 5 Concussion), to35.6Eo (associated with AIS I Left<br />
Knee Contusion) of the total associated injury incidence.<br />
The results also show that the predominant body<br />
regions vary with AIS level.<br />
. The most frequent AIS I injuries are whiplash, head<br />
contusions and lacerations, and knee contusions.<br />
("whiplash" is used as il synonym for cervical spine<br />
muscle strain). The injuries associatcd with whiplash<br />
are other back strains and knee contusions. The other<br />
associated injuries are all AIS I contusions,<br />
lacerations, and abrasions to the face and knces,<br />
except for one instance of AIS 2 concussion.<br />
("Concussion" is used as a synonym for diffuse<br />
brain injury).<br />
. Injuries to the head, shoulders, right ankle and left<br />
rib are the most frequent AIS 2 injuries. The most<br />
frequent associated injuries are primarily at the AIS<br />
I level, with a few AIS 2's and one AIS 3. The<br />
injuries associated with the shoulder are largely to<br />
the same side of the body, i.e. left shoulder fracture<br />
has associated with it left rih fracture, and other left<br />
shouldcr injuries.<br />
. At the AIS 3 level, the most frequent injuries are to<br />
the head and lower extremities. The most frcqucnt<br />
associatcd injuries are to these same body regions at<br />
the AIS I, 2, and 3 levels.<br />
Sectlon 3: Technlcal Sessions<br />
. The most frequent AIS 4 injuries are primarily to the<br />
thorax/abdomen and head. The associated injuries<br />
are also primarily to the same body region, except<br />
for a shoulder fracture associated with lcft rib<br />
fracture. The injuries associated with the AIS 4<br />
concussion are to the face and a lower lcg fracture.<br />
The severity of the associated injuries at the AIS 4<br />
level is the most diverse of any AIS level, with<br />
associated injuries from AIS I to AIS 6.<br />
. Hcad and thorax/abdomen injuries also are the most<br />
frequent AIS 5 injurics. The severity level of the<br />
most frequent associated injuries is almost as diverse<br />
as at the AIS 4 level, with injurics from the AIS I to<br />
AIS 6 levels. Most of the injuries associated with<br />
thorax/abdomen injuries arc to the same region,<br />
except for a right knee fracture as one of the<br />
associated injuries. The injuries associatcd with the<br />
head injury are to the face, rib and ankle.<br />
A few other general trends are seen in the results:<br />
. At each AIS level, an injury to the head il; either the<br />
most frequent injury or thc second most frequent<br />
injury. Lower limb injuries arc included in the most<br />
frequent injuries at thc AIS 1,2, and 3 levels, and<br />
injuries t0 the thorax/abdomen are includcd in the<br />
most frequent AIS 4 and 5 most frequcnt injuries.<br />
. For those cases where a relativcly large part of the<br />
incidence of the associated injury was found with a<br />
particular most frequent injury, the associated injury<br />
was to the $ame general body rcgion as the most<br />
frequent injury.<br />
Some limitations on the use of the results are as follows:<br />
' The national estimatcs produced from NASS data<br />
contain sampling errors because they are based on a<br />
probability sample. In general, as the magnitude of<br />
the NASS statistics decrease. the coefficicnt of<br />
variation increases, primarily bccause the numher of<br />
cases which contributed to it decrease. (The<br />
coefficient of varialion is defined as the standard<br />
error of thc cstimate divided by the estimate itself.<br />
This statistic provides an immediate comparison<br />
between thc rcliability of various statistics that htve<br />
diffcring siz.es of standard error). Conscqucntly,<br />
particular care should be used when interpreting<br />
figures based on a relatively small numbcr of cases.<br />
. Thc results descrihed here do not necessarily<br />
represent the prcscnt safety situation. After 1986<br />
both manual safcty belt usage and the portion of the<br />
fleet with automatic occupant protection incrcased.<br />
As a result, the injury patterns may have changed.<br />
. Changes between AIS 80, used here, and AIS 85,<br />
used in NASS for 1987 and beyond, are largely in<br />
the severity level of head injuries. Thus the results<br />
presented here may not be comparable with those<br />
obtained from using the later version of the AIS<br />
dictionary.<br />
153
13th lntematlonal Technlcal <strong>Conf</strong>erence on Experlmental Safety Vehlcles<br />
. NASS data are difficult to compare with other data<br />
bases, as NASS coyers injuries in police reported<br />
crashes, while many other injury data bases cover<br />
hospital discharge data. A possible mitigation is that<br />
it is rare that the more severe injuries are not<br />
hospitalized, so that the AIS 3+ injuries may be<br />
similar. Also, NASS uses a unique injury descriptor,<br />
the Occupant Injury Code, which is not comparable<br />
to hospital discharge data, which typically use an<br />
injury code from the <strong>Int</strong>ernational Classification of<br />
Discases (ICD).<br />
Conclusions<br />
An analysis of the multiple injury patterns for the<br />
most frequent injuries (MFI) experienced by occupants<br />
of motor vehicles injured in police reported crashes in<br />
thc U.S., based on 1982-1986 NASS data, confirmcd that<br />
multiple injuries are the norm. Only three of the twenty<br />
five MFI at AIS levels I through 5 occurred as single<br />
injuries greater than AOVI of the time. A large number of<br />
different injuries were associated with each most<br />
frequent injury, typically several hundred. As the AIS<br />
level of the MFI increased, the associated injury<br />
incidence increased, however, these comprised fewer<br />
different injuries.<br />
For each of the 25 MFI, the five associated injuries<br />
with the largest incidence were determined. None of the<br />
associated injurics had anywhere near the same incidence<br />
as the most frequent injury. Of the associated injuries<br />
considered, 105 out of 125 had an incidence of five<br />
percent or less of the incidcnce of the most frequent<br />
injury they were associated with. Most (but not all) of<br />
the associated injuries were to the same general body<br />
region a$ the most frequent injury. For example, femur<br />
fractures were not a frequent injury associated with head<br />
injury.<br />
The analysis was limited to the most frequcnt injuries.<br />
In most cases, the AIS level for thc five most frequent<br />
associated injuries is thc same or lower than the AIS<br />
level of the MFI. The exceptions are important howevcr,<br />
particularly at the AIS 4 and 5 levels where some AIS 6<br />
associated injuries occur.<br />
Although further work is needed before a definitive<br />
conclusion can be drawn, the results suggest that it may<br />
not be necessary to consider the effect of multiple<br />
injuries when dctermining long term consequences at the<br />
national level for the most frequent AIS l-3 level<br />
injuries. This tentative conclusion is based upon the very<br />
low relative incidence of the individual associated<br />
injuries and the clu$tering of the most frequent<br />
associated injuries to the $ame general body region as<br />
the MFI. The MAIS approach may provide acceptable<br />
estimates at the lower AIS levels. At the AIS 4 and 5<br />
levels however. further work is indicated.<br />
154<br />
At least three areas for further investigation suggest<br />
themselves:<br />
. Review the long term consequences of the multiple<br />
injury pattcrns identified here to determine to what<br />
degree earlier analyses of these consequences<br />
already include the multiple injury effect.<br />
. Compare the results derived from NASS with results<br />
derived from other injury data bases. Since most<br />
other available injury data are derived from hospital<br />
discharge records, it will be necessary to compare<br />
the subset of NASS data limited to hospitalized<br />
patients.<br />
. Extcnd the method described in the paper to enhance<br />
the overall knowledge of multiple injuries. The<br />
results reported herc show that there are so many<br />
"x", "y",<br />
and<br />
"z"<br />
injuries associated with injury<br />
"A".<br />
This is an advance over what was previously known,<br />
however, it does not show how many Axy, Axz,<br />
Ayz, Axyz, etc. injuries thcre are.<br />
Acknowledgements<br />
The valuable suggestions made by Anne Damiano and<br />
Carl Nash are gratefully acknowledged.<br />
Disclaimer<br />
The views expressed in this paper are those of the<br />
authors. They do not necessarily reflect the position of<br />
the National Highway Traffic Safety Adminislration.<br />
References<br />
Association for the Advancement of Automotive<br />
Medicine (AAAM), Abbreviated Injury Scale, 1980.<br />
Japan Research Ccnter for Transport Policy, Social and<br />
Economic Losses from Road Accidents, Junc, 1986.<br />
Luchter, Stephen, Traffic Related Disabilities and<br />
Impairments and Their Economic Consequences, SAE<br />
860s05. 1986.<br />
Luchter, Stephen, Multiple Injuries in Motor Vehicle<br />
Crashes, 34th Annual Proceedings, AAAM, October,<br />
1990.<br />
Peterson, Timothy, Iowa Safety Restraint Assessment,<br />
Iowa Methodist Medical Center. Des Moines, Iowa,<br />
Dcccmbcr, 1988.<br />
Pletschen, 8., et. al., Application of the Injury Cost<br />
Scale (ICS) to Mercedes Benz Accident Data, SAE<br />
902332, Proceedings of the 34th Staff <strong>Conf</strong>erence,<br />
November 1990.<br />
Reidelbach, W. & Zeidler F., Comparison of Injury<br />
Severity Assigned to Lower Extremity Skeletal<br />
Damages versus Upper Body Lesions, 27th Annual<br />
Procccdings, AAAM, San Antonio, Texas, 1983.<br />
Siegel, John H. et. al., Pattern of Organ Injuries in<br />
Pelvic Fracture: Impact Force Implications for<br />
Survival and Death in Motor Vehicle Injuries, 33rd
Annual Proccedings, AAAM, Baltimore, Maryland,<br />
october 2-4 1989.<br />
Siegel, John H. et. al., The Effect of Associated Injuries<br />
and Blood <strong>Volume</strong> Replacement on Death, Rehabilitation<br />
Needs and Disability in Blunt Traumatic Brain<br />
Injury, hesented at the Eastern Association for the<br />
Surgery of Trauma, January, 1990.<br />
st-w.22<br />
Crash Data Plans for the United States<br />
William H. Walsh<br />
National Highway Traffic Safety<br />
Administration<br />
Abstract<br />
With an e$timated 44,500 fatalities and more than six<br />
million police reporte
lSth lnternatlonal Technlcal Conterence on Experlmental Safety Vehlcles<br />
. Monitor the magnitude of the naffic safety problem.<br />
. Quantify the benefits resulting from proposed agency<br />
rules.<br />
The data needed to support these analytic requirements<br />
are presently obtained from a variety of sources<br />
including the police reported accident experience of<br />
indivitlual states, specialized databases created with<br />
information extracted from police accident reports and<br />
other public sources, in-depth investigations of accidents<br />
by trained investigators, and published data available<br />
from various privatc concerns and other governmental<br />
agencies such as the Federal Highway Administration.<br />
NCSA has developed four programs for providing<br />
information on traffic crashes. The Fatal Accident<br />
Reporting System (FARS) provides basic information on<br />
all highway crashes in the U.S. in which one or more<br />
people die of their injuries within 30 days of the crash.<br />
Although fatalities are the most traumatic rcsult of traffic<br />
crashes, injuries are a major component of the highway<br />
safety problem. The National Accident Sampling System<br />
(NASS) provides information from investigations of a<br />
statistical sample of police reported crashes at all levels<br />
of injury severity. NASS consists of two components, the<br />
Crashworthiness Data System (CDS) and the Gencral<br />
Estimates System (GES). In the CDS, detailcd<br />
investigations of real world highway crashes involving<br />
passenger cars, light trucks and vans are conducted.<br />
These investigations provide accurate and detailed<br />
information on the crashworthiness, or occupant protection<br />
characteristics, of these vehicles. The GES is bascd<br />
upon police reports collected from throughout the U.S.<br />
The information from these reports is used to make<br />
estimates of gcneral traffic safety measures. State data<br />
provides a large data base consisting of all police<br />
reported crashes in a largc number of States. These data<br />
files include information on crashes over the complete<br />
spectrum of crash severity from property damage to<br />
fatalities. Figure I illustrates the hierarchical nature of<br />
crash data that these data sets try to describc.<br />
45,000<br />
\ Falat Acr ,ccident ridentReporting<br />
System<br />
Fatalities \<br />
/ ,-ffi:*i"iu,.*"\,<br />
6,000,000 \*.<br />
Police Heported<br />
\<br />
Figurr 1. NCSA Crash Data<br />
13,000,000 \<br />
Unreported<br />
Crashes \<br />
rnetalEstimates<br />
Svstem<br />
Tables I and 2 provide an overview of the contract<br />
dollars and peoplc resources that flrc expended to support<br />
156<br />
Crashworthiness Data Syst6m<br />
collection and analyses of these dala sets. Each of these<br />
data $y$tems will be discussed in more detail in the<br />
following pages.<br />
Tabfs L Dets FBlatsd contrrct Program ($ooo;<br />
FY'91 FY'92+<br />
Flnl Accroetr RspoRrrre Svsret $3,397 $3,933<br />
lhttottnl Accroenr Seuplrle Svsrem 7,4L1 9,399<br />
Den Alllvsts Pnoennu<br />
SreTe Dnrn Svsreus<br />
Spscul Accrqeilr IHvesrrcATrons<br />
Tonr<br />
*FY 1992 CoHenessrorel Reouesr<br />
Tabls 2. Data Rsleted Pereonnel<br />
Fatal Accident Reporting System<br />
Federal Government PerEonnel<br />
Contract Personnel<br />
National Accjdent Sampllng System<br />
Federal Government Personnel<br />
Contract Personnel<br />
Data Analysis Program<br />
Federal Government Personnel<br />
Contrdct Personnel<br />
State Data Systems<br />
Federal Government Personnel<br />
Contract Personnel<br />
Special Accident Investlgatlons<br />
Federal Government Personnel<br />
Contract Personnel<br />
TOTAL<br />
Federal Government Personnel<br />
Contract Personnel<br />
L,575 1,575<br />
475 655<br />
300 315<br />
$13,158 $15,817<br />
FY'91 FY'92<br />
150 150<br />
(10) (ro)<br />
( 140) ( 140)<br />
170 170<br />
(13) (13)<br />
(157) (157)<br />
20 22<br />
(16) (17)<br />
t4) {5)<br />
6 7<br />
!!) !1)<br />
8 8<br />
(r) (l)<br />
(7) (7)<br />
354 357<br />
(46) (48)<br />
(30s) (30e)<br />
National Accident Sampling $ystem<br />
Crashworthiness Data System (CDS)<br />
The CDS was implementetl in 1988 as a follow-on to<br />
the Nfltional Accident Sampling System which operated<br />
from 1979 through 1986. It investigates about 5,000<br />
crashes annually, depending on the number of researchers<br />
funded. The objective of thc CDS is to provide<br />
detailed information on crash dynamics, injury<br />
mechanisms, and injury consequences for a representative<br />
sample of motor vehicle crashes to support occupant<br />
protection research and rulemaking. The CDS is a<br />
nationally representativc sample of policc reported<br />
crashes occurring on public roads throughout the United
States involving at least one towed pas$enger car, light<br />
truck, van or utility vehicle. The CDS uses trained<br />
researchers to sample crashes and collect detailed data in<br />
accordance with established protocols. Information for<br />
the CDS crashes are obtained from police accident<br />
reports, hospital records, vehicle inspection$, scene<br />
inspections, and interviews.<br />
This information is used by safety researchers to help<br />
identify safety problems for which countermeasures can<br />
be developed and to provide information to support the<br />
development of occupant protection safety standards.<br />
Table 3 provides a sample of the type of data that can be<br />
derived from the NASS/CDS program.<br />
Tabh 3. Number of Inlured Occupante by Vehich<br />
Damage, 1990 CDS<br />
0<br />
I<br />
2<br />
3<br />
4<br />
6<br />
rolel<br />
Aril ot Vrhlotr Dantto<br />
Fronr Rlghl LulI Fs{. loP<br />
9?7.OOO ?1O.OdO 2{3,000 187,000 105,000 ?3,0oo 264,000<br />
668.000 164,000 212,000 1E3,ooo e3,ooo 2,000 10s,o0o<br />
45,000 34,ooo 35,d00 12,000 31,000 " 13,O0O<br />
47,Ooo 1d,000 121000 * 9,000 r 3,ood<br />
7,000 4,000 3,000 * 2,ooo<br />
3,000 3,000 2,ooo | 2,000<br />
3.000 + 1,000<br />
7A,00o t8,d00 16,000 ts,ooo ta,ooo + 14,000<br />
1,87H,000 446,000 s?4,0oo 337,ooo 2s9,o0o 24,000 405,000<br />
-;;;;;;<br />
During Fiscal Year 1990, NCSA coordinated a review<br />
of agency crash data needs which concluded that the<br />
CDS could be modified to better providc for thc needs of<br />
the Agency. These nceds included the ability to provide<br />
an increased sample of severe crashes for clinical review<br />
while maintaining representativeness in order to produce<br />
national cstimates from the data. As a result 0f this<br />
study, NCSA has taken the following steps to improve<br />
the design of the NASS program:<br />
. Change the sampling protocols to include a stratum<br />
for those crashes in which vehicle occupants are<br />
reported by police as being severely injured and who<br />
the CDS researcher determines are hospitalized at<br />
least overnight, thereby increasing the likelihood of<br />
the crash resulting in a serious injury.<br />
. Retain the national representativeness of thc CDS.<br />
There are also several special studies that are being<br />
considered over the next several years directed at<br />
improving the usefulness of the data collected by this<br />
CDS:<br />
Speclal StudyPedestrian Data Collection<br />
A proposal has been made to collect data on<br />
pedestrian crashes at non-rural sites in CDS involving<br />
late model year passenger vehicles to; (1) establish lhe<br />
relationship between vehicle/pedestrian geometric parameters<br />
and injury type and severity; and, (2) enable<br />
Sectlon 3: Technlcal Sessions<br />
detailed accident reconshuction. The goal is to collect<br />
data from 1,000 to 1,500 pedestrian crashes annually.<br />
Most of these cases would be invcstigated to collect a<br />
basic data set for trend information. However, several<br />
hundred cases annually would be part of a detailed<br />
accident reconstruction program to produce high quality<br />
specialized data. Since this would be a major CDS<br />
program and would have a significant impact on CDS<br />
field operations and funding, the study is still being<br />
considered by the Agcncy. If pursued actual, data<br />
collection would be accomplished in the 1993-95<br />
timeframe.<br />
Injury and Trauma Dala Research<br />
Comprehensive data on occupant injuries, including<br />
injury severities, body rcgions injured, specific lesions<br />
and systems or organs injured, and the correlation of<br />
thcse injuries to specific vehicle elements or components,<br />
are essential to crashworthiness research. Recent<br />
crash injury studies, conducted in cooperation with major<br />
trauma centers, have demonstratcd the utility of additional<br />
trauma measures not currently collected by<br />
NHTSA. AIso, in this current CDS, all injury data must<br />
be manually translated to appropriatc automated codes on<br />
electronic [iles from paper copies of medical records and<br />
autopsy reports.<br />
Trauma Data Analysis. Additional trauma information<br />
(e.g., Glasgow Coma Scale, Arterial Blood Gas) and<br />
some cost data are available but are not presently<br />
collected in any NHTSA data system. Supplemental data<br />
bases will bc assembled of available data.<br />
Trauma Data Supplernent. Some injury information<br />
(approximately one-third) currently collected in the<br />
NASS CDS is potentiillly availablc from automated<br />
trfluma dittn sourccs. A progranl to explore the trauma<br />
data availitblc, and the extent of automation of such data<br />
along with the legal and privacy limitations will be<br />
undertaken. This survey will be limited to ascertaining<br />
whether or not it is possible to obtain automated injury<br />
informrtion from those hospitals currently providing<br />
injury data for NASS/CDS invcstigations. The findings<br />
of the survey will be used to plan for the possible<br />
implcmentation of this source of data within the NASS<br />
CDS, as a substitute for manually coding this infonnation<br />
from hardcopy hospital injury reports.<br />
There are several tcchnologics that are being developed<br />
or improved to increase the productivity of the<br />
CDS in the luture:<br />
Automated Injury Coding. An automated injury coding<br />
$ystem will be developed to translate hospital and<br />
autopsy reports to electronic files. Such a system will<br />
bridge the gap until more complctc automated trauma<br />
information sources are in place. Various automated<br />
approaches for coding trauma information which are<br />
being developed in the private sector for hospital use<br />
will be examined. A NASS-specific artificial intelligence<br />
conccpt wns explored in 1989-199I. A cost effective<br />
systcm or concept is needed which can be easily adapted<br />
r57
lSth lnternetlonel Technlcal Conlerence on Experlmentel Setety Vehtctes<br />
to the increasing level of detail required in trauma<br />
coding and which can accept continually changing<br />
trauma protocols (such as the shift from AIS85 to AIS90<br />
injury classification). An automated coding system will<br />
provide more complete and consistently coded injury<br />
data with fewer errors and will rcduce the cost to<br />
manually translate the records. Its application could be<br />
extended to all NHTSA data systems coding detailed<br />
trauma information, including trauma research programs<br />
at major trauma centers and other biomechanics rescarch.<br />
Crash Algorithm. A major clcment of the CDS is a<br />
measure of crash severity based on vehicle damage<br />
measurements. This severity is known as "Delta v" and<br />
is determined by means of an algorithm. This algorithm<br />
was developed in the late 1970's and work is underway<br />
to: update the vehicle stiffness properties for current<br />
cars; expand the algorithm to non-$ymmetrical crash<br />
modes (angled, offset, rollovers) frequently found in<br />
highway crashes; and devise acceptable algorithms for<br />
cases when full data are not available.<br />
Clipboard Computer. The agency will prototype a<br />
hand held non-keyboard computer to collcct accident and<br />
trauma data at the accident scene quickly and efficiently.<br />
Use of this device has the potential for greatly improving<br />
the quality and productivity ofpolice collection of crash<br />
data and improving the State's ability to update their<br />
traffic records master file.<br />
Photogrammetry. Photogrammetry is being investigated<br />
by the National Center for Statistics and Analysis<br />
as an alternate methodology to obtain vehicle crush<br />
information. It typically has required the use of expensive<br />
stereoptic metric cameras, complicatcd photographic<br />
techniques, and extensive time to plot and calculate the<br />
data. Recent advances in computers and photogrammctric<br />
algorithm development have permitted the use of<br />
standard, off-thc-shclf singlc lens reflcx camcras and<br />
personal computer software to document and analyze<br />
photos. We arc invcstigating whether this new photogrammetric<br />
software when combincd with computer<br />
aided design programs can be utilized to analyze and<br />
determine crush from photographs of vehicles where the<br />
damage has not been marked.<br />
National Accident Sampling System-<br />
General Estimates System (GES)<br />
The objective of the GES program is to provide<br />
stntistical information on the general charactcristics of<br />
the nations's police reported motor vehicle crash<br />
experience as an aid to monitoring large scale trends in<br />
the motor vehicle crash experience. GES is a nationally<br />
representative sample of motor vehicle crash data<br />
extracted from the information contained in approximately<br />
47,000 police reported crashes collected each<br />
year. It is the only database currently in place that can<br />
provide national estimates for all police reported traffic<br />
crashes on public roads, including crashes involving<br />
heavy or medium trucks, motorcycles, or non-motorist$.<br />
158<br />
It was implemented in 1988 after NASS was reshuctured<br />
to provide more information for the agency's occupant<br />
protection research and rulemaking program. No data<br />
beyond that contained on the police accident report are<br />
entered into GES. Table 4 provides an example of the<br />
type of data availablc from the GES program.<br />
Table +. Genersl Eetimates System 1990<br />
Multi-Vehicle Crashos by Manner of Collision _,and Crash Severity<br />
Propsrty Mod6rat6 S6ver6 or<br />
D6mag6 Injury Fatat<br />
Total<br />
Rear-End 998,OOo 477,ooo 50,000 1,524,000<br />
Head-On<br />
Angle<br />
35,000 32,000 17,000 85,000<br />
1,622,000 628,000 128,000 2,378,000<br />
Sideswlpe 307,000 41,0O0 6,000 354,000<br />
Total ?,962,000 1,178,0oo 201,000 4,342,000<br />
NOTE: 14,OOO crashss ot olhor Colllslon TypsE<br />
GES data are collected in 60 sites throughout the<br />
nation on either weekly, biweekly, or monthly visits to<br />
the approximately 400 police jurisdictions. During each<br />
visit, a sample of newly reported crashes are selected on<br />
a predetermined random basis to be includcd in the GES.<br />
Copies of selected police accident report$ are forwarded<br />
to a central contractor where GES data are extracted and<br />
entcred into an electronic file. Trained personnel<br />
interpret and codc data directly from each police<br />
accident report. Coding operations are carried out on a<br />
daily basis, and analysis filcs are prepared annually. Like<br />
NASS CDS, thousands of automatic edit checks are used<br />
lo assure proper values for rangc and consistency<br />
bctween different data elements.<br />
NASS/GES Future<br />
In the near term only minor changes will be made to<br />
the GES program. New variables will tre collected to<br />
support crash avoidance research and provide additional<br />
data on heavy trucks. More importantly, an evaluation<br />
will be conducted to determine what general estimates of<br />
police reportcd crash characteristics arc nceded by the<br />
agency. Alternatives to the current method of producing<br />
general estimatcs of police reportcd crashes will be<br />
evaluated to ascertain the degrec to which thcy can mcet<br />
the Agency's needs for such statistics in a timely and<br />
cost efficient manner. Among those options to be<br />
considered are model-based national estimates using data<br />
from a convenience sample of state crash data filcs, and<br />
Periodic sampling of crashes directly from state<br />
computerized files.<br />
Fatal Accident Reporting System (FARS)<br />
The objective of the FARS program is to provide<br />
information from all fifty States on all motor vchicle<br />
crashes occurring on roadways open to the public in
which a death occurs within 30 days of the crash.<br />
Information is available in the FARS that describes the<br />
vehiclcs involved in fatal crashes, their occupants, the<br />
roadways on which these crashes occurrcd, and other<br />
characteristics of interest. FARS was conceived,<br />
designed, and developed in 1975 by the National Center<br />
for Statistics and Analysis and now contains records on<br />
over 750,000 fatal crashes. FARS data are presently<br />
collected through contracts with an agency in each State<br />
government to provide information in a standard format<br />
on all police reported fatal crashes in the State. The data<br />
for the FARS are gathered from the State's own source<br />
documents and are coded on standard FARS data forms.<br />
Figure 2 illustrates a common application of FARS data.<br />
Table 5 provides an overview of the fatal crash<br />
experience in thc U.S. in 1990.<br />
d so,filo<br />
s<br />
fr +o,ooo<br />
r<br />
@ U<br />
Eso,m<br />
E<br />
s<br />
H 2o,ooo<br />
E<br />
- ro,o@<br />
0<br />
Tralfic Fatalitisg<br />
lffi 10P 1Vl 1fr6 lgt8 € lH lH 1ffi ls<br />
Flgure 2. U.S. Trafflc Fatalltiee tnd Frtllity Hater<br />
per 100 Million vehlcls Miles Traveled by Year<br />
Table 5. Motor Vehicle Traffic Fatalities 1gg0<br />
Type of Vehicle<br />
Passenger Cars<br />
Light Trucks,/Vans<br />
Medium Trucks<br />
Heavy trucks<br />
Buses and Others<br />
Utility Vehicles<br />
Motorcycles<br />
Nonoccupants<br />
Pedestrians<br />
pedalcyclists<br />
Other Nonoccupants<br />
TOTAL FATALITIES<br />
FATALITY FATE<br />
1 S90<br />
24,O25<br />
7,381<br />
133<br />
571<br />
521<br />
1,212<br />
3,238<br />
6,468<br />
856<br />
124<br />
44r529<br />
2.1<br />
a<br />
F<br />
5 =<br />
z<br />
o l<br />
4 = E<br />
e E<br />
4<br />
U<br />
,E<br />
t<br />
f<br />
{<br />
1F<br />
0<br />
Sectlon 3: Technlcal Sessions<br />
FARS Future<br />
The FARS program will remain basically unchanged<br />
in the near future. As with any data collection system,<br />
the data being collected are periodically reviewed to see<br />
if changes need to be made to better meet program<br />
needs. For instance, several highway elemenls were<br />
modified according to Federal Highway Administration<br />
(FHWA) specifications in 1987. In addition, elements<br />
were added on ernergency medical service arrival times,<br />
alcohol and drug involvement, driver zip code, and death<br />
certificate number. In 1990, another user review resulted<br />
in recommendations for 12 new data elements and<br />
modifications to 4 elements. These new factors reflect<br />
changing priorities in NHTSA's programs and include<br />
additional data on crash avoidance maneuvers, cxpanded<br />
data on heavy truck configurations, hazardous material<br />
information, and new data on drug use.<br />
In addition, there are several special studies schcduled<br />
to bc undcrtaken within the FARS data collection<br />
system:<br />
Special Drug Informailon In Selected States<br />
Several States will be testing fatally injured drivers for<br />
both alcohol and the presence of other drugs. Information<br />
will be obtained from thesc States on the drugs they<br />
tested for and the specific type of drug found in thcse<br />
fatally injured drivers. A total of I,000-2,000 drivers is<br />
the target sample size. Information on drugs such as<br />
cocaine, THC, amphetamines and other popular drugs<br />
will be obtained. This effort will be initiatcd in l-our<br />
States the first year and could be expanded to a total of<br />
10 states in the second and third year if the drug<br />
information is found to be available and useful.<br />
Detailed Injury Informailon on Surviving Occupants<br />
in FARS<br />
This initiative involves the collection and analysis of<br />
detailed injury information on the more than 40,000<br />
occupant survivors of fatal crashes. At present, only<br />
seating position and police reported injury scvcrity are<br />
obtained for these survivors. A description of the injuries<br />
sustained by thesc occupants, including body region, will<br />
be piloted in several States. NHTSA researchers will<br />
havc thc ability to study those general factors influencing<br />
survivability in these very severe crashcs. This data base<br />
is critical to the advancement of research on crashworthiness<br />
countetmeasutes.<br />
Autopsy Infttrmalion on Selected Motor Vehicle Fatalities<br />
This initiative calls for the collection and analysis of<br />
detailed autopsy information on selected motor vehicle<br />
fatalities. FARS Analysts who have access to copies of<br />
autopsy reports will collect these reports to provide<br />
detailed dcscriptions of specific injuries, causes of death<br />
and probable vehiclc contact points for pedestrians, child<br />
fatalities and motorcyclists. This will provide NHTSA<br />
rescarchers with critical data to learn more about the<br />
159
lsth <strong>Int</strong>ernatlonal Technlcal <strong>Conf</strong>erence on Experlmental Satety Vehlcles<br />
factors influencing the effectiveness of various child<br />
restraints, motorcycle helmcts and the contribution of<br />
vehicle size and shape to pedestrian fatalities. In later<br />
years, if the data proves to be useful, the program could<br />
be expanded to support the evaluation of new standards<br />
such as the side impact rule for passenger cars.<br />
TIFA Development<br />
The Trucks in Fatal Accidents (TIFA) file is a source<br />
of information that combines detailed cargo, truck, and<br />
driver data obtainable from FHWA's motor carrier accident<br />
file, but unavailable in FARS, with the detailed<br />
accident data on all fatal crashes involving trucks from<br />
FARS. Data not otherwise available to FHWA on unregulated<br />
carriers describing driver, truck configurations,<br />
and cargo is developed under a contraot with the University<br />
of Michigan's Transportation Rcsearch Institute.<br />
State Data Systems<br />
The objective of NCSA's state data system program is<br />
to fully develop the analytic potential of all state data of<br />
relevance to highway safety including police reported<br />
accident data, trauma data, and exposure data. Data from<br />
FARS, CDS, and GES are of limited utility when<br />
addressing many contemporary issues in highway safety.<br />
In particular, these data systems are not well suited for<br />
examining the stalistical relationships between spccitic<br />
vehicle design characteristics and the frequency with<br />
which they are associated with either the occurrence of<br />
a crash, or its injury consequences. While a variety of<br />
state data offer a potentially rich sourcc of information<br />
well suited for studying issues of this general nature,<br />
their application has not been fully exploited. Police<br />
rgported accident data are a readily available source of<br />
crash data, for example, but are lacking in uniformity<br />
and quality. Similarly, trauma data offer a potentially<br />
excellent source of injury information, but are not as yet<br />
available in sufficient numbers and are not readily<br />
linkable with police accident report$. The successful<br />
resolution of these deficiencies will greatly enhance the<br />
analytic utility of these data.<br />
Unfortunately, most of the data is of limited utility<br />
because of missing data elements and poor quality.<br />
Efforts are currently underway to review DOT's utilization<br />
of this data source with the objective of enhancing<br />
the efficiency with which these data can be accessed and<br />
utilized. Efforts are also underway to construct a<br />
database utilizing police reported accident data from<br />
selected States to support crashworthiness analyses, and<br />
to enhance the efficiency of Crash Avoidance Research<br />
Database (CARD) file operations.<br />
$tate Data Future<br />
CADRE<br />
A major effort to enhance the analytic utility of police<br />
reported accident data was initiated in 1990. A cooperative<br />
effort was developed with the States and other<br />
r60<br />
highway safety interests to define a core set of data<br />
elements that should be available in states' automatsd<br />
data bases. This core set of data was given the name<br />
"Critical<br />
Automated Data Reporting Elements"<br />
(CADRE). The objective of this program is to create<br />
national uniformity in a small number of variables that<br />
are essential to the use of police reported crash data for<br />
highway safety analyses. Data items have bcen tentativcly<br />
identified, public comments on the items received, and<br />
a task force assembled to review these comments and<br />
suggest changes to cADRE. A final list of CADRE items<br />
is expected by the fall of 1991, to be followed by a<br />
nationwide survey to determine the extent to which these<br />
data items are currently collectcd by States. Subsequent<br />
initiatives will he developed to facilitatc the<br />
implementation of CADRE in all States.<br />
Trauma Data<br />
A potentially rich, untapped resource for investigating<br />
highway safety issues is trauma dala. Traumfl datfl come<br />
from merging police accident reports data sets with<br />
injury information from hospital and emergency medical<br />
services data bases. Trauma data are a potentially<br />
important source of information for quantifying the<br />
relationship between crash characteristics, motor vehicle<br />
design features, and the injury consequences of motor<br />
vehicle crashes. At present, however, obstacles to linking<br />
these data with police accident reports remflin and<br />
experience in utilizing these data to address many<br />
highway safety issues is limited. Neither is there any<br />
understanding of the statistical properties of these data.<br />
Further, there is a lack of agreement as to what trauma<br />
data should be collected, and on what patients. These and<br />
other issues must be resolved before the analytic utility<br />
of trauma daia can be accurately assessed.<br />
An initial investigation of these issues is being<br />
examincd in a joint projcct with the State of Virginia to<br />
study injury mechanisms in motorcycle crashes. This<br />
projcct will provide the experience needed to assess the<br />
extent to which trauma data can support highway safety<br />
analytic requirements. This project will also assist NCSA<br />
in developing a model trauma data system and assessing<br />
the stfltus of trauma data systems nationally.<br />
U nrepor ted C r as h Analy sis<br />
Traffic crashes not reported to police have different<br />
characteristics than reported crashes. Principal among<br />
thcsc is their low severity. Many crash avoidance<br />
countcrmeasures being developed are most effective in<br />
preventing such low severity crashes. Without an<br />
accurate accounting of these crashes, it is impossible to<br />
accuratcly prcdict and assess their benefits. Further, data<br />
on time and location of unreported crashes would<br />
provide a means of assessing the vehicle-hours of delay<br />
causcd by unreported crashes, a major factor underlying<br />
the development of intelligent vehiclc highway<br />
subsvstems.
Data Analysis Program Plans<br />
NCSA is responsible for analytical and statistical<br />
$upport to the agency and thc highway safety community<br />
at large in the general areas of data analysis, sampling,<br />
and survey design. NCSA's analytic activities are<br />
typicatly undertaken in response to requests to support<br />
particular programmatic needs of the agency. Major<br />
analytic requircments are developed through an "analytic<br />
agenda" process. At the beginning of each fiscal yeru,<br />
NCSA staff meet with program representatives to jointly<br />
identify and prioritize anitlytic needs. These analyses<br />
take advantage of all of the data sets managed by the<br />
Agency. A summary of the types of analytic applications<br />
is shown in Table 6. The results of these activities are<br />
published in technical reports available to the public.<br />
Table 6. Analytlcel Appllcatlone<br />
t$$uE<br />
Crr Slzs & Wrlohl<br />
V€hicle Stabilily<br />
Llght Truck R/O Inlurl.r CDS<br />
EtfEctivensss of AOPS<br />
IVHS Utlllty<br />
Ags/Ser Fsctqr8<br />
DATA SYSTEMS AHALYNC<br />
ILErug<br />
Stat6 data, FARS<br />
stote dnta, cDS<br />
Losiitic/Linear Begresslon<br />
Loglstlc Hegression<br />
Analysis ot Varlanct<br />
Slsle data, CDS, FARS LoolEllc HEsr€ssion<br />
StstE dEts<br />
Etfect of 65 mDh SDoed Llmlt FAHS<br />
State datr, FAFE<br />
OeecrlDtlvo Stetlstlct<br />
O.scriptivs SlFtiEtlcE<br />
De8oriplive Time Sorl.a<br />
In addition to these analytic activities, NCSA<br />
publishes a number of statistical reports which<br />
summarize major aspects of the nation's crash experience<br />
on an annual basis. Included among these reports<br />
are:<br />
- Summary of Nation's Fatal Crash Experience<br />
. Crashworthiness Data System Annual Report<br />
. Summary of Nation's Policc Reported Crash<br />
Experience<br />
. MediumAleavy Truck Crash Experience<br />
. School Bus Crash Experience<br />
. Alcohol Involvement in Fatal Crashes<br />
Examples of recent analytic activities supporting the<br />
various agency program areas are as follows.<br />
Traffic Safety<br />
A major issue under study has been the effect on<br />
fatalitics of raising the spced limit to 65 mph on rural<br />
intcrstate highways. For this analysis, it was necessary<br />
usc thc Fatal Accident Reporting system coupled with<br />
vehicle miles traveled data from the Federal Highway<br />
Administration. lnterrupted time serieslinear regression<br />
models were developed using fatalities on unaffected<br />
roads as a comparison group.<br />
Other analyses recently conducted in this area and<br />
using FARS data include the effects of raising the<br />
minimum legal drinking age on fatalities, which utilized<br />
changes in the odds ratio of fatalities per licensed driver<br />
in the affected age group compared with the same ratio<br />
Sectlon 3: Technlcel Sesslons<br />
for the unaffected aie group; and the effect of<br />
implementing mandatory safety belt usage laws on<br />
fatalities, which uscd interrupted time serics/linear<br />
regression methods.<br />
Lastly, several analyses have been conducted to study<br />
the relationship bctween drivcr age/sex and .crash<br />
involvement using state data files and driver licensing<br />
data. Descriptive statistics as well as log-linear models<br />
have been developed to characterize these relationships.<br />
Crash Avoidance<br />
One of the Agency's major program initiatives is in<br />
the area of light duty vehicle rollover. The cunent<br />
initiative involves a large"scale data analysis to<br />
detcrmine which vehicle metrics best predict the likelihood<br />
of vehicle rollover in a single-vehicle crash. For<br />
this effort, it was necessary to obtain a large sample of<br />
crashes for specific vehicle makes and models in order<br />
to link involved vehicles with specific measures of static<br />
and dynamic vehicle stability. State data files from five<br />
states were selected for use, based on their high degree<br />
of reporting of the vehicle identification number (VIN)<br />
used to uniquely identify specific vehicles in the sample.<br />
Since the specific outcome under study was whether or<br />
not the vehicle rolled over, logistic regression was used.<br />
The analytical results of the first phase of this effort are<br />
being presentcd in this conference. In addition, the recent<br />
acquisition of special software for conducting logistic<br />
regression on complex survcy data has presented the<br />
opportunity to investigate light vchiclc rollover using<br />
data from the National Accident Sample System's<br />
Crashworthiness Data System. Of all of NHTSA's<br />
current crash data systems, the CDS provides the greatest<br />
level of detail on specific crash characteristics duc to the<br />
level of investigative effort invested by NHTSA.<br />
State data have also been used to investigate the utility<br />
of <strong>Int</strong>elligent Vchicle and Highway Systems and thcir<br />
opportunity for prevcnting crashcs lrom occurring. In<br />
this instance, dcscriptivc statistics on crash locations,<br />
crash mode and outcome have heen generated.<br />
Crashworthiness<br />
Two of the agency's top priority evaluation efforts<br />
over the last year focused on the relationship betwccn<br />
vehicle weight and injury severity and the effectiveness<br />
of automatic occupflnt protection systems. On the vehicle<br />
weight/safety issue several analytical methods were<br />
employed, focusing on the likelihood of occupant injury<br />
as a function of vehicle weight in the presence of,other<br />
influencing factors such as occupant aEe/sex and crash<br />
mode. FARS and state data were used to evaluate<br />
rollover risk using log-lincar regression modcls as part<br />
of the evaluation of Fedcral Motor Vehicle Safety<br />
Stnndards 206 (Door Latch <strong>Int</strong>egrity) and 216 (Roof<br />
Crush Strength). Injury risk in single-vehicle nonrollover<br />
crashes as a function of passenger car weight was<br />
assessed using data from NASS coupled with state data<br />
l6l<br />
4d<br />
i:i<br />
i:i<br />
E 'li<br />
,ij<br />
ri<br />
{ l
13th lnternatlonel rechnlcal conterence on Expertmentel sefety vehtctes<br />
in a linear regression model. Lastly, fatality risk in<br />
single-vehicle nonrollover crashes and injury risk in<br />
two-car crashes was modeled as a function of vehicle<br />
and location of impact using logistic regression models.<br />
The second major ongoing analytical effort in the area<br />
of crashworthiness is the evaluation of the effectiveness<br />
of automatic occupant protection systems. This evaluation<br />
makes use of almost all of the agency's data collection<br />
systems including FARS, NASS Crashworthiness<br />
Data System, state data and R. L. Polk new car<br />
registration files. A number of approaches are being used<br />
such as linear regression of fatalities per 100 million<br />
vehicle years a$ a function of automatic occupant protcction<br />
type and other relevant vehicle attributes, logistic<br />
regression of ejection risk as a function of restraint type,<br />
crash mode, etc., and the investigation of other descriptive<br />
statistics normalized to the expcrience of manual<br />
belt restrained front-seat occupants.<br />
Enforcement<br />
The enforcement program area generally requires the<br />
investigation of issues at the vehicle make/model level,<br />
to support compliance testing selection procedures or the<br />
investigation of alleged vehicle defects. This level of<br />
detail almost always requires the use of state data in<br />
order to obtain sufficiently large sample sizes to bc able<br />
to draw meaningful conclusions. Over the past year, the<br />
Agency has analyzed several issues including rollover<br />
riskof JeepCJ vs. other cohort utility vehicles using<br />
Iogistic regression methods; door openings leading to<br />
increased ejection risk for unrestrained occupants in<br />
specific vehicle make/models vs. vehicle cohort using<br />
simple t-test for difference in ejection rates, and ejection<br />
risk in certain vehicles equipped with a specific type of<br />
automatic occupant protection system.<br />
Plans and Policy<br />
In support of the agency's regulatory efforts, one of<br />
the missions of the Office of Plans and Policy is the<br />
development of estimated benefits from implementation<br />
of the various proposed rulemaking activitics. ln this<br />
regard, NCSA's efforts involve supporting Plans and<br />
Policy staff in developing estimates of the tflrget<br />
population. This generally involves the use of both<br />
FARS and the NASS Crashworthiness Data System,<br />
which is the only data system capable of estimating the<br />
prevalence of injury at virrious levels of scvcrity using<br />
the Abbreviated Injury Scale (AIS). In this regard NCSA<br />
provides both estimates of the current target population,<br />
imputing unknowns so as to provide a complete<br />
accounting of vehicle occupants under investigation, as<br />
well as estimating standard errors of these estimates.<br />
Since the NASS data is a sample of crashes, these<br />
estimates are subject to both sampling and nonsampling<br />
effors, the former of which can be estimated and<br />
pre$ented so the readers are awarc of the inherent<br />
variability of thc data.<br />
st.w.24<br />
A Proposal for a Simplified Injury Scale<br />
Accident Studiesr<br />
6'5A15 9" for Use in Large Scale<br />
Felix \ilalz<br />
Institute of Forensic Medicine<br />
Klaus Langwieder<br />
Office for Motor Vehicle Safety Research,<br />
HUK'Insurers' Association<br />
The Need for a Simplified Version of AIS 90<br />
The publication of the first AlS-manual in l97l<br />
immediately constituted the starting point of a ncw era<br />
in accident research. For the first time a worldwide<br />
comparability of injury-descriptive data was achieved,<br />
cnabling researchers to exchangc their experiences in a<br />
common language: the AIS.<br />
Its international acceptance, popularity and application<br />
to an increasing number of fields induced an ongoing<br />
process of refinement, which brought the number of its<br />
entries from a rudimentary 75 on the onset to about 1300<br />
in the present AIS 90 edition. Inevitably this development<br />
from a rather easy tool of injury description to a<br />
highty sophisticatcd scale with features of an expert<br />
sy$tem oriented towards research in clinical traumatology<br />
lContact<br />
arldrets: Felix Walz, MD, In$titutc of Forcnsic Medicine, University of Zurich Ziirichbergstmsse 8, CH-8O?E Ziirich, Switzcrland, Phme 0O4l<br />
| 257 2850, Fax 0O4l | 252 14 56.<br />
Consultants: K. Langwieder, A. Spomer. Th. Hrnnmel, Bf,ro fllr ltfz-Tcchnik, HUK-Vcrband,l*opoldstr.20, D-8000 Munich 40 (Office for Motor Vchicle<br />
Safety Researdr of the German Atsffiiatim of (lhird party, Accidcnt,) Motor Vehicle (md l-egal Protcction) Insurers). G. Beier, MD, Institute of Forensic<br />
Medicine' Ludwig.Maximilian University of Munich, M.G, Bcimer, MD, BG-Trauma Clinic Frank-firrt. D. Orre anrl M. Nerlich, Accident Research Unit,<br />
Medicsl School Hannover. C.R.Trcviranus, MD, Institute of Forcnsic Medicine, University of Zurich.<br />
Advisor: Eleine Petruccelli, Executive Dircctor, Association for the Advancement of Automrrive Metlicirre, 23210 Des Plaines River Road. Suite 106. Des<br />
Plaincs, IL 60018, USA.<br />
162
and allocation of resources had to come to a point of<br />
critical divergence from the needs of accident research<br />
projects.<br />
This holds especially lrue for the use of AIS in large<br />
scale accident studies limited by raw data lacking details<br />
or by encoders with little medical training. "Fahrzeugsicherheit<br />
'90" (Motor Vehicle Safety '90) is a large<br />
scale investigation of german motor vehicle accident<br />
reality of this kind for the nineties, and is currently set<br />
up by the Office of Motor Vehicle Safety.<br />
"Motor<br />
Vehicle Safety 9" embraces the analysis of<br />
some 10,000 road traffic accidents causing personal<br />
injury. Given this extent the application of the new and<br />
sophisticated AIS-90 version didn't seem promising, and<br />
therefore the idea of a reduced version of the AIS-90<br />
came up, which at the same time was desired to be better<br />
than the AIS 80 or 85 "Revision"<br />
in use beforc, but even<br />
more manageable.<br />
We started by defining our special needs as traffic<br />
accidcntologists, believing that they would conform to<br />
our colleagues' needs:<br />
. We typically dispose of summarized diagnostic data:<br />
not of detailed information as extractable from<br />
hospital treatment reports, discharge letters or<br />
operation reports;<br />
. Our data commonly is evaluated by non-medical<br />
personnel, usually by engineers, who dispose of a<br />
general medical knowlcdge, which just can be<br />
increased by a brief medical training session;<br />
, Injury paltern recognition is one of our prime<br />
interests. Refinement by itself dilutcs data into<br />
innumerable rills escaping recollection. Larger<br />
entities have therefore to be maintained.<br />
We then began to think about the means, and thought<br />
of roughly two ways to proceed:<br />
. Either one would discard uncommon injuries and<br />
their codes altogether;<br />
. or one would integrate the less common injuries into<br />
codes for frequent or for less specified injurics<br />
belonging to the samc body area and injury type.<br />
We thought that by discarding uncommon injuries,<br />
among other draw-backs, the already not entirely solved<br />
problem of multi-traumatized accident victims2 would be<br />
exacerbated. The latter alternative instead was thoueht to<br />
be practicable, and therefore chosen.<br />
Aims and Methodology of the Simplified<br />
Version<br />
The intellectual wealth connected with the AIS-systcm<br />
can't be properly described in a short publication as the<br />
present. The reader interested in a very abridged description<br />
of the Als-venture is referred to the introductory<br />
remarks in part II (the manual), which are largely<br />
Sectlon 3: Technlcel Seselons<br />
inspired by those to be found in the previous editions of<br />
the AIS-manual.<br />
Espccially the current "l990 Revision" already greatly<br />
enhanced the user-friendliness of the manual. Obviously<br />
because the maturity reached in the basic refined<br />
framework now allowed to concentrate on questions of<br />
flcceptance and ergonomy.<br />
In this contribution we too aimed at the preservation<br />
of a nearly complete upward compatibility with the full<br />
AIS-90 version, a$ was attempted in the previous<br />
revisions. We therefore set certain rules, e.g. that<br />
anatomically neighboring classes in the system's tree<br />
should coalesce only into one of their neighbor's where<br />
the label of the surviving code was still able to describe<br />
the swallowed instances correctly, although with less<br />
deiail. This label was allowed to bc amplified though.<br />
Obviously the codes and labels where injuries were<br />
transferred from werc canceled in the process.<br />
But obviously some compromise had to be made, and<br />
labels wcre amplificd accordingly. Usually the codes<br />
with the highest expected frequency and the most<br />
representative AIS-severity score were chosen, and the<br />
NFS-sign meaning<br />
"not further specified" was addcd to<br />
the label, togcther with further clarifying comments. The<br />
lowest severity level was usually also the most common<br />
one. Sometimes the codes of the former NFS'labels,<br />
those with the "99"-feature,<br />
wcrc retained. Among these<br />
also some carrying the undetermined score<br />
--9". This was<br />
intended fls a last resort for cases where hardly any<br />
information is present on considerable injuries.<br />
Overall eleven additional new codes were introduced.<br />
Two for certain lethal injury patterns, two for blunt<br />
abdominal trauma cases, one for medium size neck<br />
vessels, three for severe sprains of the spine, one for<br />
impalement-like perineal injuries, one of gradc 5 to<br />
replace high cord injuries graded 6 and one lor complete<br />
forearm fractures. Of these only five are thought to occur<br />
with a noticeable frequcncy. Wc furthermore attached<br />
certain small or rarely injured organs or structures to a<br />
larger structure in their proxirnity, when neither the<br />
consequences of the injury nor their especially protected<br />
location seemed to stand out. About twenty references<br />
tell the encoder where to go.<br />
We also attenrpted to improve the user-friendliness of<br />
the manual by giving it a closer correspondence with the<br />
occurring injury patterns, and by adding twelve<br />
suggestion lisls comprising one to three, and altogether<br />
about two dozen codes, from which to chose for<br />
additional important fcatures of the injury, implying that,<br />
were none such suggestions wcre rnade, one codc should<br />
suffice.<br />
The diamond shape of the AIS, as created with the<br />
contribution of some of the world's most eminent<br />
scientific surgical associations had to suffer from this.<br />
hee St Luchter, Isenberg R (NHTSA) The incidence of Multiple Injuries in Motor Vehicle Crashes; this volume (l3th <strong>ESV</strong>).<br />
163<br />
:<br />
.1<br />
:1<br />
r,.<br />
I<br />
.Ei<br />
,i<br />
.,j<br />
,s<br />
rn
13th lntematlonal Technlcal Conterence on Experlmental Safety Vehlcles<br />
This simplified manual can't be more than a stimulus for<br />
a debate which by necessity will have to lead to a<br />
renewed scientific effort, maybe not as large as thc<br />
previous one, but more oriented towards the aspect$ of<br />
practicability, building on what has been achieved<br />
before.<br />
For now we took up the challenge to create a<br />
practicable tool for one large data survey. We herein<br />
wanted to think of ways to anticipate cumbersome<br />
decision-making activities of the encoder, struggling with<br />
true or what to him might seem to be equivocalities. A<br />
short comment or suggestion can shorten these distracting<br />
thoughts considerably. We hope that those which we<br />
found may be prove effective in that sense. We can't<br />
hope to have forged this tool already. We are not beyond<br />
the first draft yet. But it is our firm intent to work<br />
towards the realization of a first applicable version of<br />
this tool already within 1992, and we thercfore hope to<br />
receive the necessary critique and encouragcment or even<br />
participation by March '92 in order to be able to create<br />
a prototype-proposal which can be sustained by the<br />
Injury Scaling Committee of the AAAM (Association for<br />
the Advancement of Automotive Mcdicinc) and the<br />
AAAM itself within 1992.<br />
One of the main problems arising with the reduction<br />
of thc AIS-90 code probably will be the question of the<br />
maintained validity of the Als-severity score, the heart<br />
of the AlS-system, as the severity scores of injuries<br />
coalesced into a surviving code occasionally diffcr by<br />
one step in either direction. This question can only be<br />
addressed fully by tcsting the full version against the<br />
simplified version on a large motor vehicle accident data<br />
base using a transformation software program.' Such<br />
and other tests on inter-rater reliability, acceptance and<br />
work load economy should be undertaken both in the<br />
U.S.A. and in Europc (or elsewhere) in the next future.<br />
Our first impression after a preliminary comparative test<br />
on 50 files, whose results are reportcd in part III of this<br />
publication, are favorable though, in the way that this<br />
may provc to be a surmountable problem.<br />
Ths content of this publication constitutes the first<br />
public draft of a proposal addressed at the entire research<br />
community involved in the field of traffic accident<br />
analysis. Our proposal has encountered the benevolence<br />
and intellectual generosity of the Association for the<br />
Advancement of Automotive Medicine and its Committee<br />
on Injury Scaling, and has taken already full advantage<br />
of a preliminary review provided by the Association's<br />
executive director, Mrs. Elainc Pctrucclli, within a very<br />
short delay. Furthcr comments by AIS-users intercsted in<br />
the development of the simplified version are explicitly<br />
welcome to the present task-force committee, and should<br />
be sent to the committee's coordinator Prof.Dr.Felix<br />
Walz in Zurich.<br />
The Simplified AIS-90 Injury Scalen<br />
(Simplified procedure reducing "The Abhreviated Injury<br />
Scale. 1990 Revision" of the Association for the<br />
Advancement of Automotive Medicinc, 2340 Des Plaincs<br />
River Road, Suite 106, Des Plaines, IL 60018, USA)<br />
Preliminary Remark<br />
This compendium is a proposal for a reduced<br />
procedure of AIS-coding on the basis of the original<br />
U.S.-American version<br />
"The Abbreviated Injury Scale,<br />
1990 Revision". A deeper acquaintance with the AIS, its<br />
context and the pertaining literature, can be achieved<br />
through the consullation of thc original U.S.-American<br />
version. The content of this manual should not yet be<br />
used for other than preliminary validation purposes and<br />
is therefore protected by copyright. Updatcs can bc asked<br />
for through the coordinators address until 1993.<br />
<strong>Int</strong>roduction<br />
The analysis of the effects of trauma requires a<br />
classification of injuries according to type and severity,<br />
which can be achievcd in several ways. The AIS-code<br />
categorizes injuries according to anatomical Iocation,<br />
specific type of injury and relative severity.<br />
Origin and development of the A/S. The first<br />
Abbreviated Injury Scale, whcre<br />
"abbrcviated"<br />
stands for<br />
the one- digit nature of the AlS-sevcrity score, was<br />
published in 1971. lt was developed under the joint<br />
sponsorship of the American Medical Association, the<br />
American Association for Automotive Medicines and the<br />
Socicty of Automotive Engineers by a team of about 35<br />
medical trauma specialists and engincers and encompassed<br />
75 entries.<br />
In 1973, the AAAM assumed the lead role in injury<br />
scaling and, through its Committee on Injury Scaling ,<br />
became the parent organization of the A15.6 In its<br />
second 1976 edition The Abbreviated Injury Scale<br />
accounted for little more than 200 different injuries, and<br />
this number had srown to more than 400 labels in its<br />
}tt" Si.pUn"a AIS-90 as prcsented in this paper, arr lndex-version on Excel and n cmbined veroion with the AIS85 on Exccl can be oHained from the<br />
coordinator by ryecifying the rcquired format (Macintosh or IBM or Windows).<br />
aCopy.i ght by AAAM, HUK, F.Walz/G.Trcvi rarrus.<br />
the American Arsmiaricn for Automotive Medicine was rcnamed Assciatiur for the Advancement of Automotive Medicine in 1987.<br />
6American Arsmiation for Automotive Mediciner The Abbrcviated Injury Scale. Dec Plain€s, Illinois, 1976, (,,)1980 Revision, 1980. (,,) 1985 Revision. 1985.<br />
(..) 1990 Rcvision, 1990.<br />
Petrucrlli-8. (ed.), An intemational Bibliography on Atbrcvietcd Injury Scale usage. Americrn Association for Autcrnotive Medicine. Arlingtan Heighu, Illinois<br />
(r98?).<br />
Petrucdli,E., State$, J,D., Hmes, L.N., *The Abbreviued Injury Scale; Evolution, usage and futurc adaflability," Accid Anal Prev 13: 29-35 (1981).<br />
r&
third 1980 edition. The entirely revised 1985 edition,<br />
written in "acceptable clinical language", expanded<br />
sharply to nearly 1200 entries. The 1990 refinement<br />
slightly increased the number to about 1300 possible<br />
codes, answering the still growing need for accuracy in<br />
the definition of trauma, as required by clinical research<br />
and the miilagement of resources for trauma care.<br />
The AIS 85 had a single page scaling chart, called the<br />
CAIS-85, attached to it, which proved useful in patient<br />
care, identifying patients at risk.? The single codes were<br />
reduced to their severity score, but not in number.<br />
The purposes and philosophy of the A/.S. The<br />
AlS-scale achieves the coding of injuries through a<br />
numerical key based on a slandardized descriptive<br />
terminology. It is well suited for computer processing. It<br />
has no equal in the accidentological recognition of injury<br />
distributions after car crashes.<br />
The AlS-scale spans from AIS I (minor) to AIS 6<br />
(currently untreatable) on a 6-point ordinal scale derived<br />
from an extensive consensus creating process. Severity<br />
as mirrored by treatability remains subject to the<br />
progress of medicine, requiring periodical redefinition.<br />
Severity as interpreted by biomechanical measurements<br />
remains more constant. Severity considered as individual<br />
and societal harm, not the purpose of the AIS, again is<br />
more subject to change.<br />
As the AIS scores injuries, and not consequences of<br />
injuries, it's decisive difference from other, physiological,<br />
injury scales rests in the immutability of the<br />
score in time. It considers all the defined injuries as they<br />
presented shortly after the accident, (e.g. at hospiral<br />
entry), i.e. irrcspective of outcome as influenced by<br />
complications and especially death, although it usually is<br />
computed at discharge, when the finill evaluation can be<br />
made. Some immediate consequences, such as<br />
hemorrhage, are included all lhc same. The AIS does not<br />
explicitly assess the combined effect of injuries in<br />
polytrauma. Baker's derived Injury Severity Score (ISS,<br />
1974) nevertheless gives a yery acceptable correlation<br />
with chances for survival.t It is calculated by summing<br />
up the squsres of the highest AIS score from the three<br />
body regions hit most severely. The Maximum AIS<br />
('-MAIS*) score attained in a body region is not linearly<br />
related to mortality, but it is quite useful in the<br />
evaluation of vehicle design modifications.<br />
Disabilities and impairment, a different dimension,<br />
have not bcen yet codcd for, but pertaining rcsearch in<br />
the fundamental area of combined consideration of<br />
subjective harm and loss of life expectancy, injury<br />
severity and societal cost, is underway in many<br />
countries.e<br />
Sectlon 3: Technical Sessions<br />
Changes and Improvements in the " 1990 Revisian"<br />
Improving practicability. The accuracy improved<br />
further with the current "1990 Revision" as a result of<br />
nearly two decades of clinical and research application<br />
of the system. After inclusion of penetrating injuries, the<br />
full array of neuro-trauma and external injury diagnoses,<br />
after an increasing coincidcncc with current clinical<br />
language and research into the convertability into<br />
ICD-9CM and vice versa, the -'1990 Revision" already<br />
centered on questions of practicability (as coding<br />
dilemmas, management of inadequate raw data information<br />
content, encoder assistance through synonyms and<br />
parenthetical descriptions in conjunction with improved<br />
encoder training). Suggestions from peers in Pediatric<br />
Surgery and Neurosurgery were incorporated, providing<br />
easy measurement estimation criteria for severity coding<br />
decisions.<br />
The AIS 90 used a 6-digit injury coding instead of the<br />
5-digit system of its predecessor (AIS 85) to allow for<br />
major flexibility:<br />
Structure ol the Numerical Inlury ldentiflcr:<br />
AIS 90 (and Simplified AIS 90 :H):<br />
A B C D E F G . H<br />
Body Type ot Specilic Level/ AIS score $lda<br />
region analomical anatomical Lesion<br />
structure structur€<br />
The now seventh digit holds the key element: the<br />
AlS-severity score, sepflrated by a full stop dot. The<br />
Simplified AIS 90 code (anticipating its description) is<br />
fully compatible through letters A-C, and nearly<br />
compatible bcyond. Because of thc particular spatial<br />
interest in motor vehiclc accidentology, an eight code<br />
was added (see bclow).<br />
Changes in the "Simplified AIS 90"<br />
The philosophy and method of the Simplified AIS 90.<br />
In accidentological research, and especially in retrospective<br />
studics using clinical rcports, scarce<br />
perccptibility of ac-tual injury pattcrns is a cornmon<br />
problcm. Also the extent of injury is often not well<br />
defined. Furthermore in common large sample studies<br />
even well-trained teams are vexed by the excessive work<br />
load caused by the 1300 entries of thc AIS 90.<br />
Therefore the prcsent simplificd version embracing<br />
250 entries for practical use has been developed. The<br />
following rules were established and features aspired to:<br />
'Coding should not require specialized medical<br />
knowledge.<br />
. Correlations with a) non*survival and b) overallaccident<br />
analysis should not be impaired.<br />
'Civil.<br />
J.D., Keuder, D.R., Schwab C.W.l Urc of a single page scaling chart (CAIS-85) in clinical prflctice. 3lst AAAM <strong>Conf</strong>errncr, Proceedings: 109-132,<br />
New Or{eans, LA (1978).<br />
hU. 1.p.. The lnjury Severiry Scorc of rffid rmffic casualties in relation to nonelity, time of deuh. hospiul rrcatment time and disabilityl Acid Anal Prev<br />
7:249-255 (1975).<br />
9U,S-4.r T^rk grcup (AAAM) m the Injury Impairment Scale, c/o Thonras A. Gerurarclli, MD c/o.{,AAM. Europe:EC-connrittee for lmpaiment and disability<br />
rceling c/o RDir.Dr.Krupp. Bmdesmstalt fiir Stnssenwesen, D 506O Bergisch-Cladbach.<br />
165
ISth lnternetlonal Technlcal <strong>Conf</strong>erence on Experlmental Sefety Vehlcles<br />
. Coding should allow for the successful use of not<br />
very detailed insurance reports and alike; discharge<br />
letters, operation reports etc. are missing as a rule.<br />
. The reduced code is not mcant for use in purely<br />
clinical research as in hospitals, requiring an<br />
elaborated medical documentation.<br />
General features of Simplified AIS 90<br />
. Preexisting strings don't change their meaning<br />
considerably, but rather rue strings with less<br />
specified meaning used at the expense of the more<br />
detailed ones.<br />
. Alternatively several codes of related injuries are<br />
condensed into neighboring codes, which have their<br />
meaning broadened by adding descriptive terms to<br />
their label. One of the retained strings is also labcled<br />
with the attribute: *NFS" (not further specified), to<br />
account for less specified injuries.<br />
. Simplification of the coding process through the<br />
elimination of equivocalities and orientation through<br />
comments. where codes had been eliminated.<br />
. Nevertheless, descriptive completeness is developed<br />
beyond AIS 90, despitc thc rcduction of the number<br />
of codes by 415 down to 20Vo, by providing<br />
comments.<br />
. Rate injuries, or injuries irrelevant to survival or<br />
accident analysis, were omitted.<br />
. Only a dozcn new strings were introduced. They are<br />
marked by a $-paragraph.<br />
Specific Changes Simplifying the AIS 90<br />
' In discordance with the AtS-90 cervical and dorsal<br />
vertebral injuries (fractures, luxations) are codcd<br />
separalely from injuries to the cervical, dorsal and<br />
lumbar cord. AIS-90 is somewhat cumbersome in<br />
'<br />
separating a) injuries to the Eyelin with and without<br />
fractures of the spine from b) fractures of thc spine<br />
without injury to the myelin.<br />
'A right-left side localizing eighth digit (Stde),<br />
separatcd by a horizontal line from the AIS-value, is<br />
added as new feature of the code, with five possible<br />
values; Left = l. Right= 2. Left&Right= 3. Midline,<br />
medial= 4. Unknown=9.<br />
It sing lhe N S-Dictionary<br />
The AIS-codes corrcsponding to the different injuries<br />
can be looked up under the nine headings: Head (Brain<br />
and Skull), Face, Neck, Thorflx, Abdomen & Pelvic<br />
Contents, Spine, Upper Extremity, Lower Extremity &<br />
Pelvic Girdle and External, Burns & Other.<br />
Warch out: the division according to body rcgions as<br />
used for the computation of the ISS is not identical to<br />
the above. For example, the scores in AIS spine section<br />
tht*<br />
166<br />
,*<br />
:i B*f;y';;si6;' B ffiHH<br />
j.hs;&*a{<br />
d<br />
rFcao s E<br />
li,H:, F<br />
, + tf'or"" tH<br />
5 Abdomsn tl -<br />
ll6spine<br />
1 r<br />
#<br />
7 Upper Exkdmlty<br />
h<br />
I Low6r Exlrdmily -<br />
qr ttnspecliea i .<br />
EF. Inlury Level<br />
Specilic injuries afe assigned<br />
@nseculive Uo digit nufrb6r6<br />
be0innino wilh 02.<br />
To lh6 €xlonl possiblo, wilhin the<br />
orqanizalional iramsrcrk ol the<br />
AlS, 00 ls asslgnsd lo an injury<br />
NFS as to sev€dty or wh€rs only<br />
on6 iniury is given In th€ diclionary<br />
lor lhel anelomlc slruclure 99 rs<br />
as$igned to en Inlury NFS as to<br />
l66ion Or 66v€rily.<br />
'erce" ir ured in rhis paper for the ISS-body rcgion; the tcrm 'rcgion" treing resewed to the AIS mntert.<br />
CD. Specific Anaiomic Structure or<br />
Nalure of Trauma<br />
!..', , ru4tu4,Eqq<br />
Whole Area<br />
02 Skin - Abrasion I 1. ,<br />
04 Skin - Conlusion<br />
, rL oo iri" i";","ri", I lii "Et I I<br />
, ,13 ilil,,"i#""" ir ri tr li ,<br />
;3 ;,"J1'. littLrr t<br />
I i:: i1ll,"''^e.,.. $ H ti ri t<br />
" 50 lnjury - NFS<br />
i<br />
80 Penetratins q.<br />
q E " ) .<br />
90 TrdumF, alher lhan mtrhanical<br />
i 02 Lenglh of LOC<br />
' 04 05 08 Levcl ol consciousness<br />
. l0 Concussion<br />
)<br />
i '<br />
are Essi$ned oonsecutive two digit I I I I<br />
begillins wilh.0,.3<br />
{ $,lyflb,e,l6 l $ $ i I<br />
Figure 1. SAIS 9o-Coding Scheme with Baeic Significance<br />
of Values<br />
are divided among three ISS body areas:ro lhe cervical<br />
part goes to Iss Head or Neck, the thoracic to ISS<br />
Chest, and the lumbar to ISS Abdominal and Pelvic<br />
Contents.<br />
The injuries, where feasible, have been listed in the<br />
numerical ordcr of the code, i.e. generally in the<br />
alphabctical order of the anatomical Broups and<br />
according to increasing severity. Within the extremities<br />
sections though a cenhifugal order is chosen. Vessel<br />
injuries finally are coded in an order of decreasing size.<br />
Rules for Assessrnent<br />
a) Gtneral rules<br />
l. "Questionablc"<br />
or "probable"<br />
etc. findings are not<br />
considered to be of sufficient certainty and are<br />
therefore discarded.<br />
2. Forcign bodies causing injuries are not coded for<br />
(but there is a special new code for impalement<br />
injuries under the 'AbdominaVPelvic<br />
space' path).<br />
3. Consequences of injuries (e.g. blindness) have not<br />
been coded for, as codes refer to injuries themselves<br />
(e.g. enucleation of eye); except for certain<br />
immediate conscquences as pneumothorax or<br />
hemorrhage or lcthal respiratory constriction,<br />
specified in the dictionary.
4. The kind of treatment should not influence the<br />
evaluation of the injury level (severity).<br />
5. AIS 6 may only be used for injuries explicitly<br />
marked AIS 6. Death doesn't signify AIS 6 nor<br />
vice versa. (The pre-AIS 90 term "AIS 6+" for<br />
occurred death has been abolished).<br />
Bilateral injuries to paired structures are coded<br />
separately (e.g. kidneys, eyes etc.) whenever there<br />
is a difference in severity or kind. Where there is<br />
an identity of injury in paired structures just one<br />
code is used with thc "J=right & left"-value at the<br />
8th digit "Side." Furthcrmore some injuries to a<br />
paired organ already are explicitly mentioned as<br />
such, and then again must be coded as one injury<br />
(e.g. lung injuries to both sides) even if the lesion<br />
is not perfectly identical on both sides. Identical<br />
bilateral injuries to a structure in the simplified<br />
version should be condensed in one code by using<br />
the "-l=right & left"-value at the 8th digit --Side",<br />
6.<br />
scparated by the horizontal mark: e.g., bilateral<br />
closed fractures of the radii gives: 752802..2-J,<br />
while plain fracture of the radius, right plus<br />
complete fracture of forearm, left obviously would<br />
give both 752802.2-2 and 752808.3-1($) ($=the<br />
paragraph just transiently symbolizing the newly<br />
added code). Several injuries to non-paired but<br />
symmetric structures-as to facial bones, the pelvis<br />
(e.g. the maxillary LeFort-fractures I & II or III)on<br />
the other hand still are equally considercd as<br />
single injuries, but as to their side-feature are now<br />
also generally coded as 4=midline-lesions, e.g.<br />
250800.2-4 or 25808.3-4, unless there isn't a clear<br />
laterality of thc injury.<br />
7. Opcn fractures (i.e. with an opening of the skin in<br />
continuity with the fracture) don't requirc a<br />
separate coding of the wound which is implicit, i.e.<br />
of cuts in continuity with the fractured bone, and<br />
no laceration code is therefore activated (see below<br />
under b) Special etc.).<br />
8. If certain injuries are not clearly stated or hardly<br />
defined, as for cxample, when the exact nature of<br />
a blunt abdominal injury,NFS is not known, a code<br />
with a 99-value for the Level / Lcsion (EF)-digits<br />
(in front of the full stop dot) has to be used. If not<br />
even the severity is known, these codes carry the<br />
value 9 after the full stop (AIS-score 9), signifying<br />
that no overall severity information on thc patient's<br />
injuries becomes available. Every effort should<br />
therefore be made, by scrutinizing the raw data and<br />
looking for suitable codes, in ordcr to avoid this<br />
imponderability, as such lack oI information<br />
Sectlon 3: Technlcal $essions<br />
becomes particularly bothering when considering<br />
e.g. MAIS-distributions among occupant subpopulations.<br />
9. Where the severity level of an injury is in doubt,<br />
the lower score is chosen: Code conservatively!<br />
b) Special rules regarding superficial injuries<br />
Codes from the "External" section, given their compilatory<br />
nature, may only be used where there are<br />
multiple skin injuries distributed over more than 2<br />
body regions or whcrc thcrc are no details of location<br />
available, but multiple (overall, ubiquitous) skin injuries<br />
are mentioned. Single descriptions of AISI skin injuries<br />
(not burns) of unknown location are ignorcd.<br />
"Contusion" in thc context of the {'Externsl"<br />
category, covering integumental injurics, means nonabrasive<br />
"bruise"rr or contusion of skin, subculancous<br />
tissue and superficial layers of muscles. The diagnosis<br />
may be made from an attributable tenderness alone (not<br />
due to a remote nerve irritation).<br />
A more severe true contusion referred to lesions<br />
including presumed or proven damage to underlying<br />
joints and muscles, but not to a degree allowing the<br />
notion of a "crush" injury to be applied, are to tre coded<br />
under contusion of the closest joint or undcr thc former<br />
muscle laceration code of their body region expanded in<br />
its meaning to include such severe contusions.<br />
Thoracic true contusions, not "bruises," are coded<br />
either as rib cage or as sternal contusions.<br />
"True"<br />
contusions contribute to thc ISS through the body area of<br />
their location.<br />
Calculating the Injury Severity.Score I55<br />
a) General rules<br />
The ISS is the sum of the squares of the highcst AIS<br />
values in each of the three worst injurcd ISS-body<br />
areas, which unfortunately differ from the body<br />
regions used in AIS:<br />
The six body areas used in the ISS and the AIS-body<br />
regions are:<br />
. Head and Neck (including l-HEAD (AIs), 3-NECK<br />
(Ats) and 6-5PINE/Cervical Spine 1,lts;)<br />
. Face (including Z-FACE (Ars))<br />
. Thorax (including 4-THORAX (ets) and 6-SPINE /<br />
Thoracic Spine 1rus1)<br />
. Abdomen and Pelvic content$ (including<br />
5-ABDOMEN & Pelvic contents (nts) and 6-SPINE<br />
/ Lumbu Spine (Ats)).<br />
. Extremities and Pclvic girdle (including ?-UPPER<br />
and 8-LOWER EXTREMITY & Pelvic girdle)<br />
. Externrl including 9-External, Burns, Othcr (AIS)).<br />
llBrulse = le an injury involving ruprure of snrall hlood vessels and discolorarion withour a brcak in the overlyirrg skin: CONTUSION (..) 2: ABRASION,<br />
SCRATCH (..). rbrrde = to firb or wear away especially hy friction; abrasion = (..) 2 an abraded arca of skin or nrucous merflbrene. Webster's New<br />
Collegiatt Diuionary, Springficld, MA (1979), p. l4l, p. 4.<br />
r67<br />
id .j<br />
,$<br />
:<br />
'ri<br />
!<br />
-l<br />
+ij<br />
!:t<br />
+l
13th lntHmatlonel Technlcal Conterence on Experlmental Safety Vehlcles<br />
Exrmph:<br />
lss- Hlgh.sl<br />
Body nglon Inlury Al$-Codr Als Alsr<br />
Head/Neck Cerebral contusion l6ft 140606.3-1 3 I<br />
Transection cerotid artBry 320228.5-2 E<br />
right with Bnsulng brain<br />
oamagB<br />
25<br />
Face Ear lac€rgfion, fight 210600.1-2 I<br />
Thorax Rib fractures, left side,<br />
ribs 3-4 4s0420.2-1 2<br />
Abdom€n Spl66n / superf. laceration 544224.3-1 3 I<br />
Extremitles Fracturo of femur. left 851800.3-1 3<br />
External overall abraeion8 s102ooil3,<br />
ol<br />
ISS-scores range from I to 75, whereby it may a$sume<br />
44 different values.The Maximum value ISS=75 by<br />
definition results from either three AI$ 5 injuries, or<br />
from at least one AIS 6 injury. Again: In surviving<br />
patients (without any AIS'6 value), no ISS-score can be<br />
calculated if there is an injury of absolutely unknown<br />
severity (coded AIS 9).<br />
b) Special rules regarding superficial injuries<br />
Since external injuries (Skin, Penetrating injuries)<br />
graded AIS1 or 2 are no longer asscmbled under the<br />
body region heading External, as they used to be in the<br />
AIS 85 system, unless thcy are of a multiple nature (see<br />
above), but instcad are distributed according to their<br />
location, the procedure to follow has changed with AIS<br />
90:<br />
In terms of the ISS-computation integumental injuries<br />
out$ide the "External" category, if they are marked<br />
with an Asterisk (") in the dictionary (i.e. if for<br />
instance they don't cause a blood volume loss beyond<br />
20%), confibute to the ISS by their AlS-severity scorcs<br />
(7th digit) according to the following rules:<br />
I. lf the asterisked (*) injury is the only lnjury in<br />
the Body region, locate it under "That Body<br />
region," but assign its score to the ISS-Body Area<br />
"External";<br />
If the asterisked (*) injury reeompanies (i.e. not<br />
overlying but still located in the same spatial<br />
third, midline, left, right as) an injury to a deeper<br />
structure (i.e. with a larger or equal AIS severity<br />
score), do code the integumental injury but don't<br />
assign its score to the ISS-Body Area "External"<br />
and let the deeper injury contribute to ISS alone<br />
instead. A superficial injury not in thc sarne spdtial<br />
third, midline, left, right thereforc is counted<br />
independently for ISS (unless it is not swallowed<br />
by the multiple category in the External section).<br />
This rule is a new feature of the Simplified AIS<br />
90. It is an extension of the retained rule No.3 to<br />
abrasions and bruises and an extension of its<br />
conccpt.<br />
If thc accompanied injury is an Open Fracture,<br />
lhe external injury '*overlying" 2.<br />
3.<br />
it in continuity<br />
with the fractured bone (by necessity a cut), is<br />
implicit in the code for the open fracture and not<br />
coded for separately neither for AIS nor for ISS,<br />
An injury that is not "overlyhg" the open fracture<br />
(and which therefore might not be a cut<br />
'<br />
(laceration)) on the other hand is treated according<br />
to No. 2.<br />
4. Abrasion or contusions overlying a fracture, for<br />
obvious rea$ons are not coded for in SAIS and not<br />
used for ISS. Severe contusions in proximity of a<br />
fracture comply with the Crush-injury criteria.<br />
Abbreviations and Recurring Sentences Used in the<br />
Dictionary:<br />
Nf,'S = not further specified.<br />
$ = new and supplementary Code (not contained in the<br />
full version AIS 90).<br />
r (Asterisk) = this code contributes to the computation<br />
of ISS by its AIS-severity score (7th digit) according to<br />
the special rules for superficial injuries (see previous<br />
par.).<br />
add, if appropriate: introduces suggestions for a<br />
supplemental coding of certain concomitant injuries or<br />
certain potential severe traits of an injury. It is implied,<br />
that where no suggestion is made, one code should<br />
suffice.<br />
see or code as: prccedes the path or address of the<br />
surviving label or heading, were thc prcscnt discarded<br />
one has been integratcd. The codes suggested are given<br />
either: in the form of a data bank tree path (e.g.: Thorax<br />
/ heart / cardiac valves injury 441402.3), or: I heart I<br />
cardiac valves injury 441402.3 (when the reference is<br />
located already in thc section beneath the Thorax<br />
heading), or: I I cardiac valves injury 441402.3 (when<br />
the path is a repetition of another one just mentioned),<br />
or: just as the code given in parentheses (e.g.: see Liver<br />
(54 I 828.5)).<br />
Italics anrl Other Fonts (Jsed in the Dictionary<br />
In this first public draft version of the Simplified AIS<br />
90 manual ltslics have been used to highlight new<br />
additions to the labels. Added reference of the "add. if<br />
appropriate" s1 "sse/code as" type are all newly<br />
introduced, and thcrefore not sct in italics.<br />
Nonmedical, plain English terms have been added in<br />
parentheses or vice versa according to use in current<br />
language.<br />
Elencations of anatomical substructures (as names of<br />
arteries e.g.) have bccn set in a smaller font size.<br />
The "Simplified AIS 90 dictionary of regional<br />
schemes" is presented at the end of this paper.<br />
Pretiminary Validation on 50 Motor Vehicle<br />
Trauma Case Files<br />
The purpose of this preliminary study comparing the<br />
simplificd flnd thc full version of AIS 90, was to attempt<br />
a raw estimate of the trade-off in terms of information<br />
loss and the differences between the two scales<br />
computing the ISS injury severity score. Options to<br />
counter this loss of information arc bricflv referred to.
Furthermore an in-depth analysis of the effors<br />
committed furnished insight into a possible methodology<br />
investigating fallacies while working with either scalc.<br />
Questions of acceptance, also amongst non'medical<br />
u$ers, are addressed besides interrater reliability.t2<br />
As a result of this test, and the advice from E.<br />
Petrucelli and others, the Simplified AIS 90 underwent<br />
a further in-depth review with the intent to overcome<br />
equivocalities and to facilitate coding decisions<br />
especially for non'medically trained users, and to<br />
highlight areas for further debate.<br />
Materidls and Methods<br />
Two test persons with medical degrees were given<br />
fifty identical case file sets of data related to injuries of<br />
motor vehicle accident victims. Test person A is an<br />
expert in the field of road traffic accident data analysis<br />
who has been using mainly the AIS 80 for several years.<br />
Test person B comes from a background ofseveral years<br />
in trauma surgery, but has no previous coding experience<br />
with AIS.<br />
The sets used were the first 50 sets of raw personal<br />
injury data (mainly medical insurance reports) from<br />
inter-passenger frontal car collision files, which belong<br />
to the "Motor Vehicle Safety 90" file collection<br />
mentioned in Part I, satisfying 2 criteria: at lea$t one of<br />
the two drivers had been killed and at least one of the<br />
drivers had been wearing a safety belt.<br />
Both test persons worked through the coding<br />
procedures without double-checking systematically, i.e.<br />
in one go, without correcting the results immediatcly<br />
themselves, and without excessive motivation to avoid<br />
mistakes, as the investigation of potential errors wils one<br />
of the purposes of the study.<br />
After completion the two sets of data undcrwent a<br />
systematic error analysis procedure looking for errors of<br />
omis$ion, invention, distortion, orthography, ovcr- and<br />
underrating of "contusions,"<br />
redundancy and lack of<br />
precision, both by inventing and omitting information.<br />
The error retrieval procedure was made as severe a$<br />
possible, while the crileria for the "correct answers"<br />
were by necessity often debatable. Next, the etfect on the<br />
distribution of Maximum AIS-severity scores and enors<br />
in computing thc Injury Scverity Score were analyzed,<br />
and the overall influence of errors expressed in the<br />
*'mean"<br />
ISS-deviation from the "true" score.<br />
Finally the distributions of the Maximum AIS-severity<br />
scores and ISS-scores were compared bctween thc two<br />
scales on the grounds of the "corrected"<br />
results.<br />
1?eszlts and Discussion<br />
Besides one autopsy case with cranio-ccrvical<br />
dislocation. only non-lethal injuries were coded. There<br />
was a clear prcponderance of cervical and thoracic<br />
<strong>Section</strong> 3: Technlcal Sessions<br />
injuries. Among the more $evere injuries there was a<br />
Chance-fracturc with concomitant duodenal and hepatic<br />
injury.<br />
Coding error analysis. Error analysis disclosed an<br />
overall per ca$e'-error" rate of 1.3 for test person A and<br />
of 1.5 for test person B respectively.<br />
TGrt rGrulta<br />
No. of dr.urltlos - 50. Each lett.er slgRlfleE on€<br />
error, 'r' stands for error implementing AIS 90, 'b'<br />
for error committed on both scales,<br />
't'<br />
fof error<br />
using'sAlS 90'onIY.<br />
TeaE perBonr Cod€r A coder B<br />
codGr. . .<br />
1. External<br />
2. other<br />
fnven tedr<br />
bbbbb bbb aa bbbbb bbbbb bbbb ee<br />
aa bbbbb ss aa bbbbb<br />
2. Other - IEJurIca<br />
E.rroneoua InJury !<br />
cod.d. but not figuring in the raw datar bb<br />
1. External<br />
0 abb<br />
2. Oth6r<br />
aa bbbbb bbb bbbb I<br />
orEhoqraphy I<br />
a aaabss<br />
'Contusions'r<br />
1 , OverraEed<br />
2, comFrehension<br />
by oEher code<br />
Unpre(:i se i<br />
1 . wasC lng<br />
informat ionr<br />
2, InvenLing<br />
i n format i on r<br />
bbbbb b aaa bb<br />
bbbbb aa b ss<br />
a aaaaa bbbbb ss aaaaa bbb aaEE<br />
a b a s<br />
As can be seen from the above there was a rather even<br />
frequency of errors of "wasting information" (l5,SVo<br />
mean) or "overrating<br />
contusions" (7,SVo); (scc remarks<br />
on contusion in the Rules for external assessment in the<br />
Manual's introcluction), and a barely noticeable tendency<br />
to code slightly more than one knew (37a). Encoder B<br />
though made a 3Vo of "frank invention" errors.<br />
Encoder A was leading in crrors coding non-external<br />
injuries erroneously (llVo), or not at all (14%), but was<br />
only half as bad in omitting external injuries. L4Vo of<br />
errors were made, giving codes which seemed redundant<br />
because implied by severer injuries already coded for<br />
(e.g. thoracic contusion on top of fractured sternum).<br />
Encodcr B had not much consideration for external<br />
injuries, committing ?4Vo of his crrors by omission and<br />
llVo by underrating contusions. Spelling and legibility<br />
caused \Vo of his errors, a fourfold of his colleagues<br />
rate. Still he also caused 1Vo of his errors by not<br />
correctly coding injuries to correctly identified<br />
non-external structures, and 9o/o by forgetting some<br />
altogether.<br />
Encodcr B was not nruch advantaged by the simplified<br />
version, scoring 207o one-scale errors instead of 26Vo in<br />
the full version, which he used first. Encoder A made<br />
three of four errors in both versions, which he used<br />
concomitantly. Obviously the'-wasting information"<br />
error was not easily achieved using the simplified<br />
version, but still with a 1-to-3 ratio in Encoder A, and a<br />
4-to-5 ratio in Encoder B.<br />
ItCibo*, G.; *lndices of severity for medical evalutiqr studies: rEliability, validity anrJ data rcquirements," Amual metting of the Americnn College of<br />
Emcrgency Physicians, New Orleans, tA (Oct 1976).<br />
169
l3th |/f,ternatlonal Technlcal Conlerence on Experlmental gafety Vehlcles<br />
Influenee of errors on MAIS- and lSS-distributlon.<br />
of frequencics is shown:<br />
lTj-:.:::y.ff-tabre<br />
ltrtt 1<br />
TAIA E<br />
nrs 3<br />
xtta I<br />
nra 5<br />
taAtS 6<br />
AIF 90<br />
Cddsr A 'True' Coder B<br />
sAls 90<br />
Coder A 'frue' Coder B<br />
18 18 18 l4 11 L7<br />
t9 19 2t 23 27 24<br />
6 9 8 9 8 5<br />
6 2 1 3 3 4<br />
- 1 1 -<br />
l l l l l l<br />
Next the same table is shown, with added relative<br />
differences of each rater's results lrom the "True"<br />
values. The difference of the SAIS 90 "True" values<br />
from the AIS 90 "True" level are set in italics:<br />
nra-ilL.trlt{rtloDr IeveIs fron 'True'<br />
columh6 (put=zero) shown,<br />
'True' sAIs 90 ie ehown with an added lcvcl fron'True'AIs 90.<br />
I.IIA I<br />
rltt I<br />
II.IA 3<br />
talrS a<br />
LtrS 5<br />
l|lrS 6<br />
AIS 90<br />
coder A .True. Coder B<br />
l8<br />
1 9<br />
0<br />
0<br />
l8 0<br />
1 9 0 2<br />
18<br />
7 +<br />
0<br />
2 2<br />
14 +J<br />
3 - 4<br />
ll<br />
2 1<br />
-7<br />
+ 8<br />
l7 +6<br />
2 4<br />
6 - - 3 9 0 8 - 1 9 + 7 8 - t s<br />
5<br />
-<br />
l<br />
+<br />
-<br />
0<br />
{<br />
7<br />
l<br />
2<br />
1<br />
0<br />
0<br />
0<br />
I<br />
1<br />
l<br />
- J<br />
0<br />
0<br />
3<br />
-<br />
L<br />
0<br />
0<br />
0<br />
3 +<br />
* -<br />
L<br />
I<br />
l<br />
0<br />
4<br />
1<br />
0<br />
0<br />
18 0<br />
19 0<br />
9 0<br />
2 0<br />
t 0<br />
7 0<br />
sArs 90<br />
coder A rTrue. coder B<br />
An extract of the previous table shows the two scales<br />
compared:<br />
ttttS*itlrtrlliltlfir cxtrrct f ron pr.vlous trbl..<br />
'True'sAtB 90 ie ghown with an added level frah'True'AI5 90.<br />
nra I<br />
x r a I<br />
x t a 3<br />
nra I<br />
nf,ta t<br />
Tf,TA '<br />
AIS 90<br />
11 -7<br />
2'1 +8<br />
3 +I<br />
- -I<br />
I O<br />
Differences in scoring-frequencies beyond a range of<br />
plus or minus one (lLVo of values) are found only as a<br />
shift from AISI to AIS2, which is ncarly entirely due to<br />
the newly introduced subdivision of neck injuries with<br />
the consecutive upgrading of certain (in this sample 6)<br />
injuries to AIS 2. This had a marked influence on the<br />
lower tail of this sample's distribution, due to a<br />
preponderance of 12 neck injuries (24Vo of cases). The<br />
arguments for this important subdivision still remain<br />
valid though, and a skewness at the lowest ratings seems<br />
negligibte.<br />
The effects of errors on the final ISS-scores arc shown<br />
in an abridged manner, where stepwise approximations<br />
of the "True" ISS are shown in the condcnsed form of an<br />
otherwise only ordinally meaningful "mean" ISS:<br />
'Xitnr f88 toorat of itrco.l.r,t ri.ultr<br />
(with no other than ordlnal error quantlflcatl6n neanlng)<br />
AIS 90 sArs 90<br />
ISS-acoteE: raH 8,4/9,3<br />
8.7/8_8 (9.6) r<br />
rfbar ooff6cb1on,,, l<br />
of l66-conputation: 8.719.3<br />
of Als-€valuationr 9.0<br />
(1.e.'True score')<br />
sArs 90<br />
'Tru€'<br />
8.6/ (9.4) r<br />
9.1 (9.3)*<br />
'withaut caseF conputlng IEs dedplte AIs-9 scdre (put=0)<br />
utln error sour4es:<br />
1) computinE rsg de6plte Arg-9 6dore (put=o). 2) computing Ars<br />
90*Iss without ruleE Bupplefrefitary to AIs 80. 3) Hlatakes<br />
intrgrating Ars body (sub) regions into l6g-body area8.<br />
170<br />
It is apparent from the above, that this rather crude<br />
overall piuameter seems to be robust versus a change<br />
from AIS 90 to SAIS 90.<br />
Conclusions<br />
The apparent small differences in severity outcome<br />
classifying the individual injury with a simplified scale<br />
which has its entries reduced to a fifth of the full version<br />
would seem to constitute an accsptable trade-off.<br />
Furthermore at least in this minimal preliminary study<br />
inter-rater differences have been far larger, as can be<br />
seen easily from the data. If this result should be<br />
confirmed by larger tests, and by using the reviewed<br />
public draft as found below, it becomes obvious, that<br />
efforts to improve accuracy should be oriented towards<br />
encoder haining and didactic improvcments in the<br />
dictionary and thc pertaining presentation of rulcs. No<br />
forecast can yet be made as a result of this study.<br />
If there should prove to be major distortions betwsen<br />
the overall severity ratings between AIS and SAIS, one<br />
could opt for selective corrections of single codes at<br />
their seventh digit. The prerequisite for further efforts<br />
will obviously be the confirmation of improved handling<br />
characteristics of the simplified vcrsion. Wc will<br />
undertake appropriate tests ilt ths near future.<br />
Acknowledgments<br />
This simplified AIS is being devclopcd in collaboration<br />
with the Association for the Advancement of<br />
Automotive Medicine (AAAM) and its Committee on<br />
Injury Scaling. The authors acknowledge the contribution<br />
of Elaine Petrucelli in reviewing this draft and of<br />
Mr.G.Treviranus MD who was responsible as trauma<br />
consultant for the final review (and partial translation) of<br />
this paper and the manual contained in it. He also<br />
realized the preliminary validation of the SAIS together<br />
with Mr. W. Hell MD, accidentologist, who made<br />
valuable contributions to the manual as well. This project<br />
was supported by the following institutions:<br />
. HUK-Verband (German Association of Motor<br />
Vehicle Insurers) who initiated the project, provided<br />
the basic financial support and organized the<br />
project's coordination and the meetings of the<br />
Consulting Group;<br />
. the Swiss Fcderal Fund for Traffic Safety (FVS),<br />
Bern, which supportcd thc work of the consulting<br />
Sroup at thc University of Zurich.
lffiltsatlon filuryrhactfltm<br />
Simplified AIS 90 dictionary of regional schemes<br />
Simplified AIS-90 Version 1.0 - first public draft - Xlllth <strong>ESV</strong>, Paris 1991<br />
Head (Brain, Skull)<br />
"Closed<br />
hef,d Injury",<br />
"traumatic<br />
brain injury.,<br />
"craniocerebraltrauma',<br />
NFS<br />
Scalp<br />
Abrasion, contusion, hematoma, wound < 10 c'm<br />
Wound > 10 cm and into subcutaneous tissue<br />
Wound causing blood loss >20% ol blood volume<br />
Entlre Head<br />
Penetration through skull, > 2 cm into brain<br />
Crushing injury ot both skull and brain<br />
"Decapitation"<br />
Ganhlnerust<br />
Bra|nsterfl (hypothalamus,<br />
medulla, midbrain, pons)<br />
Gembellum<br />
(inf rate ntorial,posterior fossa)<br />
Gerebrum,<br />
"Brain"<br />
Slarll, cranlun<br />
l+wlof Conechmnesr<br />
Awake on admission<br />
Unconsciousness<br />
Concussion<br />
Face<br />
Skln (incl.eyelid, external<br />
ear,lips<br />
Sectlon 3: TsE'hnlcel Sessions<br />
Al$Code<br />
115099.9<br />
110099.1.<br />
11 0604.2.<br />
11 0806.3<br />
116004.5<br />
113000.6<br />
code as verfebral dislocation 650204.2 angl<br />
neuro-injury brainstem 140214.6 or mrd laceratlon<br />
aN bilateral severc carctid aftery lesion 320228.6$ for<br />
lower level separation.<br />
Contusion, laceration, posttraumatic palsy<br />
130299.2<br />
NFS, Contus io n, herniationdiff . axonal i njuty, hemorh age 140299.5<br />
Massive destruction, crush.<br />
140214.6<br />
Contusion, dilfuse axonal injury NFS<br />
140402.3<br />
Hematoma epidural (extradural), suMural, intracercbellar 140410.4<br />
hematoma or infarction zndary to ertracranial vessel injury<br />
small supeilicial wound or contusion or infarction of<br />
si ze =
lSth h//]ternetlonel Technlcal <strong>Conf</strong>erence on Experlmental Setety Vehtctes<br />
172<br />
l-ocelbatlon<br />
Ir,lorlth<br />
Eye (withont lids)<br />
Itlbndlble ( lower ja,'r)<br />
iltililh (upper jaw)<br />
Nose<br />
Orbfta (eye socket):<br />
zygome (cheek bone)<br />
Ethnrold<br />
Teeth<br />
I Iniurythscrlptlon<br />
NFS, soff tissue injury to tongue ot to gingiva ol<br />
salivary glancls (except parotis, see 210604.2 )<br />
superficial injury, (nof beyond fhe /ens), NFS<br />
f njury beneath the lens, rupture, enucleation<br />
foss of o4lan, (not "blindness")<br />
Fracture, closed<br />
Fracture open, comminuted or displaced (r1cm)<br />
Frrcture of lower jaw alvaolar Hocess<br />
D is locatio n, s pai n (te mpo ro m and ibu lar jo i nt)<br />
Fracture, closed<br />
fracture of upper jaw alveolar process<br />
Fracture, comminuted or open or<br />
separation of upper base from skull (LeFort lll)<br />
Fracture with bleeding (maxillary art.)> 20% blood volume<br />
Contusion, fracture<br />
add, if apprcpriate:<br />
SkitV wound >1Ocm or Skin/ blood loss > 20Vo<br />
Fracture of roof or comminuted<br />
code as<br />
Brain, SulU basal skullfraclure<br />
Fracture ol remaining parts, non-comminuted<br />
Fraclure<br />
(code as basal skull fracture)<br />
loosened, dislocated<br />
Als-code<br />
243299.1<br />
240499.1<br />
240402.2<br />
250602.1<br />
250610.2<br />
251 699.1<br />
250800.2<br />
250808.3<br />
250810,4<br />
251099.1<br />
150200.3<br />
251200.2<br />
2s1800.2<br />
e51499.1<br />
lleck (only soft tlssues, excludlng cervlcal splne)<br />
Entlre neck<br />
"Decapitation"<br />
codo as vertebral dislocation 650204.2 aN<br />
neuro-injury brainstem 140214.6 or ffird laceration<br />
and bilateral severe carotid aftery lesion 320228.6$ for<br />
lower level sepaation.<br />
Skln<br />
Abrasion, bruise/contusion, hematoma, wound < 20 cm 3100S9.1<br />
Cefttld afiery<br />
(Common, intemal)<br />
Wound > 20 cm reaching into subcutaneous tissue<br />
Partial (intimal) tear, perforation, NFS<br />
Complete laceration with severe bleecling<br />
310604.2<br />
320299.3<br />
320212.4<br />
TeaL throtnfusis with ensuing brain damage 320214.5<br />
Bilateral severe carotid artery lesion with ensuing brain death 3?0228.6$<br />
other mairr ned(vessels Carotis extema, jugularis, vertebralis: any injury 322099.2$<br />
tarynx<br />
Contusion 3402SS.2<br />
Ttrytoid and cricoid<br />
Perforation, rupture, crush 340208.3<br />
cartilage (Adam's apple) thyroid, hyoid<br />
Pharynx<br />
Contusion<br />
340699.3<br />
(Upper throat)<br />
Thyroid gland<br />
Salivary glands<br />
( Parutid, submandibulai<br />
sublingual)<br />
Thorax<br />
Perforation, rupture, crush<br />
340608,4<br />
NFS see injury to larynx<br />
for parotid o r NFS see severe cut or contusion of f ace (21 0604. 2)<br />
for the remaining glands see injury to mouth (243299. 1 ) .<br />
Entlrcthorax<br />
Blunt trauma NFS<br />
Open<br />
Skln<br />
"sucking"<br />
chest wound<br />
415099.9<br />
415000.4<br />
Bilateraf crush with severe lung injuries ot constriction 413000.6<br />
Paralytic o r exte rnal constrictive re spi ratory arrest<br />
414000.69<br />
Abrasion, bruise/contusion, hematoma, wound < 20 cm 41 0099.1.<br />
Wound > ?0 cm reaching into subcutaneous tissue 410604.2.<br />
Avulsion, wound >20cm,blood loss >20% of blood vol.,<br />
female breast laceration<br />
410806.3<br />
Bmast, female<br />
avulsion code as previous ilem
Localbdlon<br />
Inlurydetctlptlfi<br />
Sectlon 3: Technlcal $esslons<br />
AIS-Code<br />
Thordcmda<br />
Perforation, small contained tear, NFS<br />
Tear, large, contained, large surrounding hemaloma,<br />
420208.4<br />
420216.5<br />
hemomediastinum<br />
Complete laceration with esanguination (lethal bleeding)<br />
add, il appropriate<br />
Thora< / heart / cardiac valves (heart valve) iniu+ 441402.3<br />
or: Spine/ thoracic cord /contusion / permanent paraplegia '<br />
420218.6<br />
Other naned \re8sel$<br />
complete cord svndrome 640420.5<br />
or: $pine / thoracic cord / contusion / permanent (transient)<br />
paraparesis, i nco molele cordsvndrome- 6404 1 0.4 ( 64040 0.3)<br />
Perforation, minor tear, NFS<br />
(esophageal, intercostal code as:<br />
int. thoracic /"mammary" /Pleuralcavity/ Hemolhorax with 20% volume blood loss 442208.4<br />
Iriledlrotlnum<br />
Hernomediastinum<br />
code as:<br />
/Thoracic aona contained aortic tear<br />
420216,5<br />
lrtgednuays (bronchus)<br />
(for main stem bronchus<br />
Laceration, pedoration, NFS<br />
Avulsion, detachment, transection, tearing-off<br />
440208.3<br />
440216.4<br />
see trachea)<br />
Dlaphnagm<br />
Laceration, rupture<br />
440604,3<br />
tor bowell [ivar herniation into thoracic cavity<br />
aftl, if appropriate: Hemo-/pneumolhorax code ( 442202.3)<br />
for rmderate cases, while for large bowel/ liver herniation AEld<br />
Tension pneurTpthorax code ( 442210.5)<br />
Esophagus<br />
Heart<br />
Transection , laceration, NFS<br />
Contusion<br />
440808.4<br />
441002,3<br />
Tear<br />
441 012.5<br />
-Pericardium<br />
Ruptu re, muhiple perforations<br />
Tamponade without heart iniury herniation af heaft<br />
(igmre minot peicardial iniuries)<br />
441016.6<br />
441606,5<br />
Cardiac valves (heart valves)<br />
Central arterio-venous f istula<br />
Lung<br />
Laceration<br />
e.g. ventriculat or atrial ssptum perforation<br />
( al so ao rto -pu I mo n a ry f i st u I a, si n u s V a I s alv a- pe rfo ratio n)<br />
Contusion, superlicialtear (only if documented )<br />
( Documentation : radiological, surgical, pathological ;<br />
pulmonary dysfunction is insufficient evidence)<br />
441200.5<br />
441300.5<br />
441402.3<br />
(Add rib frac{ures<br />
Laceration, NFS<br />
441414.3<br />
il appropriate: but nglhemoor<br />
pneumothorax)<br />
Bilateral laceration<br />
Bilateral laceration with pneumothorax or massive<br />
441450.4<br />
441458.5<br />
air leak<br />
Thoracic cavity<br />
- Pleuralcavity<br />
Trachea<br />
Rib cags<br />
Sternum (breastbone)<br />
Massive internal or external bleeding >20% blood volum6<br />
Hemothorax, pneu mothorax<br />
Tension pneumothorax<br />
bfood loss >20V" blood volume<br />
Tear<br />
Complete laceration, separation from larynx<br />
Contusion ot rib cage with intercostal demage<br />
Frecture NFS or not more than one rib lractured<br />
Fracture ol 2 -3 ribs<br />
Fracture of> 3 Ribs, but with stable Thorax<br />
Unilate raf , f lail (u nstable) chest w all, p arado x b re athi ng<br />
Bihteral<br />
Flailchest
lSth <strong>Int</strong>ernetlonal Technlcal Conterence on Experlmental Satety Vehlcles<br />
r74<br />
l-ocaltsafibn ffi.ryOeecrtptton<br />
ORGANS<br />
Adrenalgland<br />
AnUs<br />
Bladder<br />
and lowar half of uretsr<br />
Colon (large bowel)<br />
Duodenum<br />
(1st part ol smallintestine)<br />
AIS-Code<br />
Abdomen and Pelvlc Contents<br />
Dhphragm Laceration, rupture<br />
for fuwel / liver hsmiation into thoracic cavity<br />
440604.3<br />
illfl, if appropriate: Hemo-/pneumothorax code ( 442202.3)<br />
for moderate cases, whih for large bowel / liver harniatio n gglll :<br />
Tension pneumothorax code ( 442210.5)<br />
"Blunt<br />
abdominal injury"<br />
severe<br />
"blunt Abdomen<br />
515099.9<br />
aMominalinjury"- NFS<br />
s 150s9.3$<br />
Bleedlng, intra-abdominal Scant hemorrhage<br />
or retroperitoneal<br />
see /AMominal wall etc./contusion 540010.2<br />
Moderate to severe =
l-ocallsatlon Injurydeealptlon<br />
Pelvis (sacrum, ilium, ischium, publs, acetabulum) see LOWER EXTREMITY/ Pelvis<br />
Lumbar Spine<br />
see under SPINE / lumbar sPine<br />
Rib cage<br />
see under THORAX / rib cage<br />
SPINE / Cervlcal splne<br />
Entire Cervical Spine<br />
'Decapitation<br />
Cervical cord<br />
(Myelon)<br />
(some uselul sensation or<br />
motor function lell)<br />
(no sensation, no motor function)<br />
(no sensation, no motor f unction)<br />
(no s€nsation, no motor f unction)<br />
venebra/ D,bc<br />
Nerves<br />
SPINE / Thoraclc Spine<br />
Entire Thoracic spine<br />
Thoracic cord<br />
(Myelon)<br />
Venebra / Disc<br />
Nerues<br />
SPINE / Lumbar Spine<br />
Entire Lumbar spine<br />
Lumbar cord<br />
aN Gauda<br />
Sectlon 3: Technlcal Sess/ons<br />
AIS-Code<br />
Neck injury (without fracture or luxation))i.e.: ceruical<br />
or related pain, muscular stiffness, dizziness, fatigue,<br />
depression, autonomic distu rbances,'tivhiplash", N FS.<br />
"<br />
, severg, lasting for more than three weeks<br />
640278.1<br />
640280.2$<br />
codaas: ve ftebral dislocation 650204.2 d4d<br />
neuro-injury brainstsm 140214.6 gr mrd laceration<br />
A14lbilataral severe carotid aftery lesion 320228.6$ for<br />
Iower level separation.<br />
Contusion NFS, including reversible quadriplegia<br />
Laceration (or any injurfi cEiusirp permanent -<br />
- (but incomplete) quadriparesis,<br />
- incomplete cord syndrome<br />
- (L ate ral (B row n- Sdqu ard ), a n te rio r, ce ntr a I c o rd s y nd ro me )<br />
NFS as lor location<br />
640200.3<br />
640242.s<br />
Laceration (or any rhlury) causlngEelnallgnl... :<br />
Quadriplegia, NFS<br />
640260,5<br />
Quadriplegia C4 or below<br />
640261.5<br />
Quadriplegia C3 or above<br />
(including patients saved by resuscitation)<br />
640280.5$<br />
Ad(Lif appropriate:<br />
Paralytic or extemalconstrictive lethal resplratory anest 414000,6$<br />
Dislocation. subluxation<br />
(predominant soft-tissue injury no fracture except small flake)<br />
650204.2<br />
Fracture 650216.2<br />
(Dlsco|dar|t ro AF-90 rf#turE end dlslocatb|tcode-q should be added to<br />
codes br eventral cerulcal co|d les|ons)<br />
Injury, lesion, postraumatic paresis, NF$<br />
630299.2<br />
(Roots, trunks/divisions/cords (brachial plexus)<br />
Sprain pain, muscular splinting (without fracture/dislocation) 640478.1<br />
'<br />
, severe, hsting for nnre than 6 weeks 640480.2$<br />
Contusion NFS, includi ng transient paraplegia<br />
640400.3<br />
Contusion<br />
640410.4<br />
640420.5<br />
(continued)<br />
630600.3<br />
650404.2<br />
630499.2<br />
- with petsarc-0l paraparesis,<br />
incomplete cord syndrome<br />
(Lateral (Brown-S6quard), anterior cotd syndrome )<br />
Paraplegia, conplete cord syndrome<br />
(nor sensation nor motor func{ion)<br />
Conus medullaris lesion $Eg<br />
Luntar sprine / lumbar cord I cauda Equhe syndrome<br />
Dislocation, subluxation<br />
(predominant soft-tissue injury, no fractur€ except small flake)<br />
Fracture 650416.2<br />
(Dlscordam b AF9O fr*tun and dlsbcallon#des should be added to<br />
codee br eventr.nl cellCd COd leSlOm).<br />
Injury, lesion, paresis<br />
(Roots, trunks/d ivisio ns/cords (brachial plexus)<br />
Distorsion with pain, rnuscular splinting (without<br />
f racture/dislocation), Sprain, Disc inlury<br />
sgvere, hsting for rnore lhan 6 weeks<br />
Contusion, gvgn incl. transient paraplegia<br />
Contusion - with permanent paraparesis<br />
Paraplegia (nor sensation nor molor function)<br />
Cauda equina syndrome or conus medullaris lesion<br />
640678.1<br />
640680.2$<br />
640600.3<br />
640610.4<br />
640620.5<br />
630600.3
ISth lnt&rnatlonal Technlcal Conterence on Experlmentel Safety Vehlclas<br />
t76<br />
lncalEatlon<br />
Vertebra / Disc<br />
NervEs<br />
Arms (Upper<br />
Skin<br />
Entire Arm<br />
Clav'rcle<br />
Shoulder<br />
Scapula<br />
"Arm-,<br />
Hand-, Lower Arm"<br />
Humgrus<br />
(Upper arm)<br />
Ellbow<br />
(Olecranon)<br />
Radius<br />
(Spokebone)<br />
Ulna<br />
Wrist<br />
Garpus and Metacarpus<br />
(Hand excluding wrist and<br />
fingers)<br />
Finger<br />
Injurydecufibn AIS-Code<br />
Dislocation, subluxation 650604.2<br />
(predominant soft-tissue injury no fracture except small flake)<br />
Fracture (e.9. Ghance-fracture) 650616.2<br />
(Dlscolt|ant b AlS.90 fractule and dlslocatlon+odes should be added to<br />
codss br evgntual cerulcal cord bslons)<br />
Injury lesion, paresis<br />
630699.2<br />
(Root$, trunke/divieions/cords (brachial plexus))<br />
Abrasion, bruise/contusion, hematoma, wound < 10 cm<br />
Wound > 10 cm rsaching into subcutaneous tissue<br />
Degloving injury to arm or lorearm gor major avulsion<br />
For degloving injuries to fingers code 752406.2<br />
For degloving injuries to wrist code 710604.2.<br />
Major avulsion with blood loss > 20Yo blood volume<br />
code as: 714002.2 and afterial laceration 721008.3<br />
Amputation<br />
Crush (severe soft tissue / muscle destruction)<br />
A rterial laceration with severe bleeding<br />
Venous laceration with severe bleeding<br />
code as: Axillaryvein laceration<br />
Nerve lesion ( median, radial, ulnar Nn.)<br />
Muscfe faceration, avulsion severe contusion<br />
Fracture<br />
Contusion of rotetor cuffand joint<br />
Dislocation<br />
Laceration into joint code as crush 751050.3<br />
Crush (massive destruction<br />
of soff fissues) or laceration into joint<br />
torfracturc head ot humerus a:dd752602.2<br />
forfracturo gcapula add 753000.2<br />
Fracture<br />
Fracture, NFS<br />
Fracture, closed<br />
Fracture open, comminuted<br />
Contusion<br />
Dislocation<br />
Laceration inlo jolnt, open dlslocation<br />
Crush (massive destruction of<br />
sort frssues)<br />
Aibl, if approprtaE: fracturc ol humerus<br />
AEEI, if appropriate: fradure of ulna<br />
Fraclure. closed<br />
Fracture open, comminuted or<br />
Fracture of radius ildulna ("lowey arm fracture")<br />
Fracture. closed<br />
Fracture open, comminuted<br />
Fracture of radius and ulna ("lower arm fradure")<br />
Contusion<br />
Dislocation<br />
Laceration into joint, open dislocation<br />
Crush (massive destruction of soft tissues)<br />
agE, if apprcpriate:lradure of Radius<br />
ag!g!, if approprtaE: frecture of ulna<br />
Fracture<br />
Fraciurg<br />
710099.1.<br />
710604.2-<br />
714002.2<br />
711000.3<br />
713000.3<br />
721008.3<br />
720206.2<br />
(continued)<br />
730420.1<br />
740400,2<br />
752200.2<br />
751010.1<br />
751030.2<br />
751050.3<br />
753000.2<br />
751800.2<br />
752602.2<br />
752604.3<br />
75061 0.1<br />
750630.1<br />
750640,2<br />
750650.3<br />
75?80?.2<br />
752804.3<br />
752808.3$<br />
753202.2<br />
753204.3<br />
752808.3S<br />
751410.1<br />
751430.2<br />
751440.2<br />
751450.3<br />
75?002.2<br />
752404.1
l-ffillsatlon<br />
lcEs ftouerextremity) & Pelvis<br />
Skin<br />
Entire leg<br />
VESSEL$<br />
Pelvis<br />
(lliac wing,<br />
Pubic ramus,<br />
Acetabulum<br />
Coccyx)<br />
Acetabulum<br />
851808.3Sacrum,<br />
llium,<br />
&lschium<br />
Sacrum<br />
$ymphysis<br />
Hip<br />
Gmin<br />
IniurydescflPtlon<br />
Crush (massive<br />
destrudion ol bone and<br />
sotf trssues, degloving iniurll<br />
Abrasion. bruise/contusion, hematoma, wound < 10 cm<br />
Wound > 10 cm, reaching into subcutaneous tissue<br />
Wound > 10 cm, reaching into subcutaneous tissue with<br />
blood loss > 20o/" blood volume<br />
Amputation, NFS<br />
- below knee<br />
- abovs knee, or thtough knee<br />
Hemipelvic amputation code as abdomen / pelvic<br />
space / impalement 5.'1i1228,5$<br />
Crush (severe sott tissug / muscle /bone destruction), NFS<br />
Contusion, severe or compartment syndrome<br />
or severe muscle lschemia<br />
- below knee<br />
- above knee or thtough knee<br />
Fernoraf anery rnallr or bilateral laceration<br />
with very severe bleeding >20% blood volume<br />
and /or severe muscle ischemia<br />
A rterial laceration with severe bleeding<br />
arrd /or sevara muscle ischemia(ppliteal arlery)<br />
Venous laceration with severe bleeding > ?0y" blood vol.<br />
Nerve injury (femoral , tibial, peroneal Nn. )<br />
Nerve injury to sacral roots see<br />
Lumbar spine / lumbar cord / cauda equina syndrome<br />
Muscle laceration (rupture, tear, avulsion)<br />
Tendon laceration, rupture<br />
Fracture {with or without sacroiliac dislocation) (Pelvic ring<br />
fracture, Malgaigne) with large deformation and severe<br />
blood loss >20% blood volume<br />
add, il appropriate:<br />
Abdominal aorta / comrnon lliac art./ laceration 520204.4<br />
or<br />
// complete laceration with esanguination (very severe<br />
blood loss) 520208.5<br />
add , il appropriate: for tracture ol sacrum with<br />
major nerve lesion:<br />
Spine,lumbar / lumbar cold / cauda equina syndromg<br />
630600.3<br />
code as /Pelvis (Pubic ramus)/ fracture NFS 852600.2<br />
Contusion<br />
Dislocation cods as<br />
Fraclure and/or dislocation head of lemur<br />
Laceration into ioint<br />
Destructive massive laceration (e.9. rollover injury)<br />
code as<br />
iCrush (severe soft tissue / muscle /bone destruction)/<br />
Sectlon 3: Technlcal Sesslons<br />
AIS-Code<br />
75?408.2<br />
810099.1'<br />
810604.2.<br />
810606.3<br />
811000.3<br />
81100?.3<br />
811004.4<br />
813000.2<br />
813002.2<br />
813004 3<br />
820208.4<br />
821008.3<br />
821206.3<br />
830604,2<br />
630600.3<br />
840600.2<br />
840802.2<br />
Fraclure NFS, (iliac wing, pubic ramus,<br />
852600.2<br />
Coccyx, acetahrlar (hip joint cup)), closed<br />
Symphysis pubis disruption (=a 2 sm1<br />
Fracture (as above) open, displaced (> 4cm), comminuted 8s2604,3<br />
Symphysis pubis disruption (> 2 cm)<br />
add , if appropriate:<br />
Fracture ldislocation of head of femur<br />
Fraciure (with or without sacroiliac dislocation)<br />
852800.3<br />
moderately displaced (=
13th lntematlonal rechnlcal conterence on Expertmentet sefety vehtcles<br />
l-ocalhadon<br />
Femur<br />
Knge<br />
Tibia<br />
(Shin-bone)<br />
Fibula<br />
(Splint-bone)<br />
Ankle<br />
Ankle fractures<br />
Iniuryd#c|ttbn<br />
- above knee 813004.3<br />
add, if appropriate<br />
/Fernoral adery major or bilateral laceration 820ZOB.4<br />
add. it appropriate: for severe Testis injury:<br />
Abdomen/Perineum,external Genitals llarger wound<br />
e.g.Testis, avulsion, destruction 543224.2<br />
Condylar fracture<br />
"<br />
lf < l2yearsoH<br />
Fracture head of fernur and/or dislocation<br />
Fracture neck of femur<br />
Fracture shalt of femur, NF,S<br />
"<br />
iil < 12 yeaEoH<br />
Contusion<br />
Dislocation<br />
code as /Disruption 840406.3<br />
gglgl, if appropriate:<br />
/Vessels:A rterial laceration with sevsre bleeding<br />
and /or severe muscle ischemia<br />
(popliteal artery) 821 008.3<br />
Laceration into ioint<br />
$prain, incomplete Ligamentous Injury<br />
1 complete Collateraland/or 1 Cruciate ligament tearl NFS<br />
Disruption (anterior and posterior-(a)-Cruciate tigament tear<br />
with collateral ligament or menisceal injury<br />
Patella, fracture<br />
Fracture, closed, NFS,"Lower leg"<br />
Condylar fracture, tibial plateau fracture<br />
add, il appropriate:<br />
/ Knee / Disruption (840406.3)<br />
Fracture shaft of tibia, mdial malleolus, closEd, NFS<br />
Fracture shaft of tibia, mdial malleolus, open,<br />
comminuted<br />
Fracture of f ihJla,ratara I malleolus, closecl, NFS<br />
F ractu re, /afara I malleolu s, ope n, comminuted<br />
Contusion of ankle and foot<br />
Sprain<br />
Dislocation, i.s. ungfrbhiury to ankte<br />
(also dislocation of "foot with talus", or of talus)<br />
Ligament rupture, ffihlehjury to ankle,<br />
avulsion fracture<br />
Ankle fractures:<br />
1 .Stable fracture. non-comminuted, NFS<br />
Fracture to elther meclial (tibia) malleofus<br />
r lateral(fibula ) malleolus,<br />
(or frac{ure to both mentioned as 'stable')<br />
codg as:<br />
/Ligament rupturs, staDts rniu44o ankle<br />
pUs:<br />
the appropriate item lrom<br />
this Hl for the bone frac{ure:<br />
for closed Medlal malleolus fracture,<br />
/Fracture shaft of tb,la, medial malleotus, closed, NFS<br />
for open Medial malleolus fracture,<br />
/Fracture shaft of libia, medial matleolus, open,<br />
for closed hteral malleolus fracture:<br />
/Frac{ure of frrrh, closed, NFS<br />
lor open Lateral malleolus fracture,<br />
AIS-Cocle<br />
85r 804.3<br />
851806.2<br />
851808.3<br />
851812.3<br />
851814.3<br />
851816.2<br />
850802.1<br />
850818,2<br />
850826.2<br />
840404.2<br />
840406.3<br />
852400.2<br />
853404.2<br />
853406.2<br />
853420.2<br />
853422.3<br />
851606.2<br />
851610.2<br />
850202.1<br />
850206.1<br />
850210.2<br />
840402.2<br />
840402.2<br />
853420,2<br />
853422.3<br />
851606.2
l-ocalbatlon lniurydeEcrfplfon<br />
Foot Fint<br />
Foot<br />
Toe<br />
/Fracture of fibula, open, comminuted<br />
2 . llnstable lractu re-fHclurtudislocation,<br />
co m m i n uted anklqlraclure<br />
( 'Bimalleolar'fracture, unless not mentioned as stable,<br />
Trimalleolar f racture') ol<br />
fracturesofboth malleoli, unlsss not mentionsd as stable,<br />
code as<br />
Dislocation, i.e. /4'g'abla lnluryto ankle<br />
For the bone frac{ure add:<br />
the appropriate item from the above Ist.<br />
Dislocation, subluxation (Lisfranc, sublalar),<br />
(with or without flake fracture)<br />
Dislocation of 'foot with talus', or of talus<br />
see Ankle / Dislocation<br />
Sprain, avulsion fracture<br />
Fracturo base of sth m€tatarsal<br />
Contusion of ankle or foot<br />
Fracture<br />
Fracture<br />
Crush, amputation<br />
Sectlon 3: Technlcal Sesslons<br />
AIB-Cotle<br />
851610.2<br />
85021 0.2<br />
850402.1<br />
850404.1<br />
850202.1<br />
852000.2<br />
853602.1<br />
853606.2<br />
Erternal--<br />
Preliminary remaft: Before you start to work with this section be sure to be familiar with the content of the following<br />
two paragraphs of the Manual's <strong>Int</strong>roduction: Rules for Assessment / b) External injuries (see p. X<br />
and Calculating the Injury Severity $core ISS / b) Extemal injuries and ISS - 90.<br />
Multiple,"'overall/ubiquitous' Abrasion 10200.1<br />
Contusion/bruise,<br />
..:_s L^HA.^E^,i_^,<br />
hematoma,(incl.eventualabrasion) 910400.1<br />
" Wound (Crush injury Laceration, Cut) 910600.1<br />
Skin avulsion I 1 0800. 1<br />
Burns ---<br />
Dsgres AIS-Code<br />
(it"superticiar"2o msntioned, oode as lo)<br />
(if '-fullthicknes$<br />
Extenslon in%olTBS<br />
burn" mentioned, code as 2o- 3o)<br />
total body surface (rule of 9s)<br />
unspecif ied<br />
1" (superficialT)<br />
2o -3" NFS NFS<br />
=< 50"/" ol > 12 months old<br />
> 50% and =
lSth lntematlonal Technlcal <strong>Conf</strong>erence on Experlmental Satety Vehlcles<br />
l-ocalbatlon<br />
I I<br />
I<br />
18<br />
FHOTIT<br />
18<br />
EAGK<br />
Iniurydesrfrlon AIS-Code<br />
Rule ol Nines - The Total body surface is divided into percentages by multiples of nine %.<br />
(Reprinted in the A|S-Manual's "1990-Revision' with permission of the American Burn Association and<br />
the American College of Surgeons).<br />
OtherTrauma<br />
Inhalation inju ry ( including u nintentio nal CO-exposure) l<br />
< 20 mg"/" carboxyhe moblobin9 1 9202.3<br />
20 - 40 mg% carboxyhemoblobin<br />
> 40 mg% carboxyhemoblobin<br />
Hlgh vohage electdcal injury<br />
NFS<br />
(a$lto burn iniury code)<br />
919204.4<br />
919206.5<br />
919400.2
st.w-25<br />
Various Aspects on Crashworthiness Calcutations<br />
M. Igarashi and K. Nagai<br />
Suzuki Motor Corporation<br />
Abstract<br />
In the last few years, computer simulation has been<br />
increasingly utilized as a method for seeking optimal<br />
body structure and improved occupant protection. Simu'<br />
lations of this type are particularly attractive since they<br />
can be used in the early stages of design and $ubstituted<br />
for much more costly and time consuming actual vehicle<br />
barrier tests. Recently, there has been significant progress<br />
in increasing the reliability and accuracy of<br />
computer simulation of crashworthiness in various crash<br />
modes. These are due to improvement in both computer<br />
hardware (more efficient and lower costs) and computational<br />
software (computer codes and calculation models).<br />
This paper presents results of a computer simulation<br />
using finite element analysis for predicting various<br />
Sspects of crashworlhiness. The results of these<br />
calculations are in good agreement with experimental<br />
observations. Continuing efforts to improve both the<br />
computer hardware and computational softwarc should<br />
further extend the application of these techniques and<br />
result in optimal structural design for specific vehicles.<br />
<strong>Int</strong>roduction<br />
Presently, large scale calculations of crashworthiness<br />
in automobiles have been widely studied by various<br />
organizations, and their results are, in most cases,<br />
effective and promising. In fact, in frontal crashworthincss<br />
calculation the results of simulational calculations<br />
compares very favorably with experimental observations.<br />
This is due mainly to (1) recent advances in computers,<br />
(2) the advent of non-linear and large dcformation codes<br />
such as DYNA3D, and (3) more accuratc and practical<br />
modeling techniques.<br />
As a progress has been made in crashworthiness<br />
calculations, their practicfll application in car body<br />
design has been increasing since such calculations have<br />
advafiages such as shortening of dcvclopment time and<br />
a reduction in the number of car crash experiments<br />
required. This fact actually accelerates the improvement<br />
of crashworthiness calculations with better reliability and<br />
accuracy. As a result of these $equence$, there is<br />
incitement in interest developing it as a standard<br />
engineering design tool.<br />
This paper presents several examples of large scale<br />
crashworthiness calculations in various aspccts of an<br />
automobile crash. Although approximately one third of<br />
fatal car accidents in Japan(r) are frontal collisions,<br />
serious injury and fatality are also seen in other types of<br />
car accidents such as sidc and oblique impacts, or rear<br />
impacts. Thus, in order to increase the integrity for<br />
Sectlon 3: Technlcal Sesslone<br />
crashworthiness, studies of various types of crash<br />
calculations are required. The authors feel that the<br />
extension of crashworthiness calculations to various<br />
aspects of the crash will greatly enhance the structural<br />
integrity of the car body and increase crashworthiness in<br />
thc very near future.<br />
Since improvements in the computer program<br />
(DYNA3D) have recently been made resulting in better<br />
calculation accuracy and reduced calculation time, this<br />
paper will describc it and highlight some results from its<br />
use.<br />
Outline of DYNA3D and Its Update<br />
,:<br />
DYNA3D, originally developed by Dr. Hallquist of<br />
ti:<br />
Livermorc Science Technology Corporation, is a .+<br />
completely vcctorized, explicit finite elemcnt program<br />
for solving three-dimensional, inelastic, and large<br />
deformation structural dynamic problems. The basic<br />
features of this program and its theoretical background<br />
have been already introduced in prior papcrs.(2)(3x4x5x6)<br />
This paper discusses recent improvcmcnts of the Suzuki-<br />
DYNA3D. These improvcmcnts/updating of the code has<br />
been accomplishcd not only by our efforts but also<br />
considerably by Dr. Hallquist's work,<br />
Highlights of recent improvements/updates in the<br />
DYNA3D include:<br />
(l) A function for re-numbering both elements and<br />
nodes has been added. Since FEM modeling of an<br />
entire car body usually rcquires considerable<br />
engineering man powcr, sevcral engineers (modelers)<br />
often work together to produce a full scale mcsh<br />
model by sharing portions of the car body mesh<br />
gcncration. In the final stagc, each portion of the<br />
mesh model is combincd so as to generatc an<br />
integrated full nrcsh model. This new function<br />
therefore greatly simplifies this process.<br />
(2) To facilitatc a detailed investigation of calculational<br />
result, a function was added to store specific output<br />
data such as load, displacemcnt, velocity,<br />
acceleration, stress and strain from a specific file.<br />
With this function, the size of an output file can be<br />
readily rcduccd or increased dcpcnding upon the<br />
availability of a file memory.<br />
(3)<br />
The calculation CPU lime of a mesh modcl is<br />
govcrned by the critical tintc integration step siz-e<br />
which is determined by element sizc and material<br />
sound spccd. This means that as thc size of an<br />
element becomes smallcr for better accuracy, the<br />
CPU time must be increased. Thcrcfore, in order to<br />
monitor the current timc step size in a calculation<br />
and also to estimate the total CPU time, the print out<br />
choice of the time step and the corresponding<br />
element are available.<br />
'ii
l3th <strong>Int</strong>ernatlonal Technlcal <strong>Conf</strong>ercnce on Expertmentat Safety Vahtctes<br />
(4) Laminated windshield glass can be modeled.<br />
(5) The code can not only be used for with double<br />
precision but also single precision without any loss<br />
in calculational precision.<br />
(6) The strain rate can be input for a certain type of<br />
materials through load curve definition. The dynamic<br />
behavior of some materials is influcnced strongly by<br />
the strain rate. This added function enables<br />
dramatically improved calculation accuracy for<br />
plastics, and other non-linear materials.<br />
(7) Catculations of the effective plastic $fisss-strain<br />
curve is accomplished intcrnally by the code.<br />
Accordingly, the total stress-strain curve obtained<br />
through an experiment can be input directly.<br />
(8) A function to switch from a rigid body to a<br />
deformable body (normal FEM element) and vice<br />
versa as a restart calculation has been added. This<br />
function is manually flagged, not automatically<br />
incorporated in a problem.<br />
(9) Other: the input and output method has been<br />
improved resulling in enhanced input and output<br />
handling as well as better graphic display.<br />
Various Aspects on Crashworthiness<br />
Calculation<br />
Large scale crashworthiness calculation$ were initially<br />
studied on so called frontal impact;(') i.e. in which a<br />
vehiclc hits to a rigid wall with a certain speed. Because<br />
the calculations are relatively straightforward, many<br />
rcsearchcrs have initiated studies to increase calculation<br />
accuracy and improved modeling techniqucs for this<br />
particular crash mode.(7x8xexr0) This movement was also<br />
associated with the fact that the number of fatalities<br />
caused by frontal impacts such as a cflr to barrier impact<br />
and a car to car collision is particularly large throughout<br />
the world, although thc actual percentage varies from<br />
country to country. Another motivating features was the<br />
fact that we felt it desirable to have a computational tool<br />
for investigation of better crashworthiness pcrformance<br />
thereby decreasing the burden of full-scale tests of<br />
prototype vehicles. Due mainly to such the demands,<br />
large scale frontal crash simulation has been widely<br />
studied and utilized throughout the automotive industry.<br />
The authors would classify this period (1986-1989) as<br />
the lst stage in crashworthiness calculations.<br />
Once structural analysts and engineers become<br />
accustomed to this calculation tool, it is natural that they<br />
would try to extend its applications. Such attempts hilve<br />
been aided by recent advances in computer and also the<br />
advent of improved FEM programs such as DYNA3D.<br />
These most recent applications of crashworthiness<br />
calculations-which can be classified as the Znd stage of<br />
crashworthiness calculations-will now bc discussed.<br />
Full Fronlal Impact<br />
The F'EM model, shown in Figure 1, was used to<br />
analyze a frontal barrier crash. The mesh shown has<br />
182<br />
about 14,000 shell elements and 12,000 nodes to<br />
represent a typical small sized vehicle. The front<br />
bumper, engine, transmission and front suspcnsion<br />
including tires, are all incorporated in the model.<br />
Furthcrmore, a side door and steering column shaft are<br />
also modeled to better simulate the actual vehicle and<br />
produce better experimental results. Thc inertia of the<br />
reil suspension, components placed in the compartment<br />
such as seats, instrument panel and other parts are<br />
incorporated in thc modcl by scaling their masses and<br />
distributing them about thc places where they are<br />
attached to the car body. As the result, the mesh has the<br />
correct overall mass. The initial velocitv was takcn as<br />
50 km/h.<br />
Figure 1. Undeformed Mesh ol Small Sized Car Body:<br />
Frontal Barrier lmpact<br />
Figure 2 shows the deformed shape at 50 msec after<br />
impact. Figures 3 and 4 show comparisons of acceleration<br />
and velocity between calculation and experiment at<br />
one point in the side-sill member. As seen from these<br />
figures, the calculated values agree quite well with the<br />
experimental results. In particular, the dynamic movement<br />
of the steering column shaft can be calculated with<br />
reasonable accuraoy. Five hours of CPU on a HITAC<br />
820/60 (manufactured by Hitachi) wcre required for this<br />
calculation.<br />
Figure 2. Deformatlon at 50 msec After Frontal lmpect
h $<br />
x<br />
";^ 4<br />
d<br />
S g<br />
g<br />
c 2<br />
.9<br />
i : l<br />
o<br />
E ()<br />
€ o<br />
810<br />
U'<br />
.E<br />
5<br />
F ()<br />
e<br />
0 2 0 4 0 6 0<br />
Time (msec.)<br />
Flgwe 3. Acfflerstlon Ghange During Frontal lmpact<br />
t5<br />
-5<br />
100<br />
0 20 40 60 80 100<br />
Time (msec.)<br />
Figure 4. Vsbcity Change During Fronlal lmpect<br />
An article by Nilsson discuss in detail the deformation<br />
of the steering column system under the frontal<br />
impact.(r')<br />
Another advent of the recent frontal barrier crash<br />
calculation is a capability to simulate the kinematics of<br />
an occupant (dummy) kinematics with an airbrg. This<br />
calculation was studied by Schelkle et al.(r2) using the<br />
existing FEM code with a newly developed airbag<br />
model. The authors feel that the calculation techniques<br />
presented there is one approach for extending<br />
crashworthiness calculational applications.<br />
Angular Impact<br />
Figures 5 and 6 show the undeformed mesh and<br />
deformation at 60 msec, re$pectively, for the case of a<br />
30 degrees angular impact at an initial velocity of 50<br />
km/h. The FEM car body model used for this calculation<br />
was basically the some model as that used for the frontal<br />
impact calculation. As a result that there was essentially<br />
no difference in CPU time bctween the frontal impact<br />
and angular impact calculations.<br />
Figures 7 and 8 show comparison of acceleration and<br />
velocity between calculation and experiment for this<br />
case. Although there is no exact peak to peak agreement<br />
in acceleration, once it is integrated, reasonable concla-<br />
<strong>Section</strong> 3: Technical $essions<br />
tions were obtained. As far as car body deformations are<br />
concerned, a calculation accuracy of 80-907o has reccntly<br />
been achieved in both frontal and angular impacts.<br />
However, more extensive studY is needed to accurately<br />
predict occupant dynamics.<br />
Flgure 5. Undeformed Mesh:30 deg. Angular Barrlsr<br />
lmpect<br />
Figure 6. Deformstion at 60 msec After 30 deg. Angular<br />
lmpact<br />
H<br />
o<br />
x<br />
N<br />
d<br />
oU'<br />
E<br />
E<br />
't<br />
(d<br />
o<br />
o<br />
{<br />
3.0<br />
e.5<br />
2.0<br />
1.5<br />
1.0<br />
0.5<br />
0.0<br />
ExD6rlment<br />
- Celculatlon<br />
r,{\ (i" i<br />
I<br />
l1<br />
l<br />
,<br />
I<br />
,i\<br />
I<br />
I<br />
l ,<br />
0 10 20 go 40 50 60<br />
Tlme (msec.)<br />
Figure 7. Acceleration Change During Angular lmpact<br />
Car to Pole Impact<br />
A car to pole impact is another crash configuration<br />
that is commonly seen in rcal world irccidents. Therefore,<br />
,<br />
I<br />
I<br />
183
1ath lntematlonal Technlcal Conterence on Expeilmental Safety Vehlcles<br />
15<br />
()<br />
(l)<br />
g 10<br />
E<br />
'5<br />
o 9<br />
o,<br />
Experlment<br />
Calculatlon<br />
0 10 20 30 40 50 60<br />
Tlme (msec.)<br />
Figure 8. Velocity Change During Angular lmpact<br />
a car body structural investigation of crashworthiness<br />
performance for a car to pole impact is important. In<br />
particular, the acceleration pulse of the car body under<br />
a car to pole impact will influence the airbag sensoring<br />
system since this type of impact is relatively soft. There<br />
could therefore, be a delay in the acceleration pulse to<br />
the sensors if the front end car body structure is not<br />
designed so as to effectivcly transmit the pulse to the<br />
specific location whcrc the sensor is attached.<br />
Figure 9 shows the undeformed mesh, and Figure l0<br />
shows the body deformation at 50 mscc with an impact<br />
velocity of 50 km/h for this case. Figure I I shows a<br />
comparison between calculation and experiment for the<br />
acceleration at one point in the side-sill member. Then<br />
comparing the dcformed body shown in Figure l0 with<br />
the one shown in Figure 2, there is quite a large<br />
difference between the respective body deformation<br />
modes. For the case of frontal barrier impact,<br />
deformation is relatively simple. The impact (kinetic)<br />
cnergy is mainly absorbed through (l) buckling (2)<br />
plastic deformation (compression) and (3) friction of<br />
each member and component over the entire width of thc<br />
car. On the other hand, for car to pole impact, the impact<br />
energy is not only absorbed by the mechanisms<br />
mentioned above but also by tension and bending<br />
phenomena. Figure l2 shows the comparison of the ratio<br />
of the impact energy absorbcd by main structural<br />
components between in a car to pole impact and in a<br />
frontal barrier impact. The same FEM model and the<br />
same crash speed were used for both calculations.<br />
As shown in Figure 11, there is little difference<br />
between results from calculations and cxperiments in<br />
terms of the time at which the maximum acceleration<br />
occurred and its peak valuc. The cxact cause for this is<br />
still under study. The authors presently feel that based on<br />
the current FEM modeling technique, the limited time<br />
(man power) spcnt in modcling, and available CPU time<br />
(as modeling bccomes finer and more precious, CPU<br />
time increases drastically to as much as 30-50 hours.<br />
This would not be realistic), it could be difficult to<br />
184<br />
Figure 9. Undeformed Mesh; Cer to Pole lmpect<br />
Figure 10. Deformation at 50 msec After Fole lmpecl<br />
= 8<br />
x<br />
6<br />
c i 4<br />
(I'<br />
g z<br />
E<br />
0<br />
tr<br />
€ -z<br />
Eq) -4<br />
(IJ<br />
()<br />
f; -6<br />
0 20 40 60 80<br />
Time (msec.)<br />
Figure 11. Acceleretion Change During Pole lmpact<br />
obtain a better correlation than that shown in Figure ll.<br />
At the same time, the experimental data may not<br />
accurately represent what actually happens during<br />
impact. The sitmpling frequency and filtering frequency<br />
adopted by the experimental measurement system may<br />
result in uncertainty. Nevertheless, the authors are<br />
continuing efforts to further refine the method to bring<br />
about better correlation between calculation and<br />
experiment.
Frontal lrnpscl<br />
Pole lmpacl<br />
IlBumperEFront<br />
E ? Front ond stdo<br />
E3Flrewall & Cowl<br />
E 4 Front lloor<br />
E S Slde doors & Floof<br />
Q 6 Powar lraln<br />
I 7 Tlrss<br />
E I Suspenslon<br />
Figur 12. Comperison of Crarh Energy Abrorbed by<br />
llaln Components Between Frontal lmpact and Pole<br />
lmpact<br />
Frontal Impact with Partial Overlap: Offset Crash<br />
Another frontal impact configuration is a frontal<br />
impact with only partial overlap. The importance of a<br />
considcration for this type of offset crash is well<br />
discussed by Grosch et al.(r3) When real-world frontal<br />
crashes are considered a frontal impact with only partial<br />
overlap is often seen. The reason for this is that most<br />
drivers try to steer away from a collision at the last<br />
moment of crash, resulting in striking the opposing<br />
vehicle or barrier with less than half the front end alea<br />
of the striking vehicles. This is also true for vehiclcs<br />
impacting obstacles such as poles and trees. When<br />
comparing paflial overlap impact with full frontal<br />
impact, it is noted that although the same impact energy<br />
should be absorbed in both cases, there is a large<br />
difference in the energy absorbing mechanisms for these<br />
two impact configurations. For the case of the partial<br />
overlap impact, in the beginning the impact energy is<br />
absorbed by a small part of the front end structure. This<br />
may result in larger deformation than that observed at<br />
the full frontal impact. There seems to as yet be no<br />
concrete structural guideline established, but the continuous<br />
accumulation of this kind of simulation study will<br />
obviously play an important role in establishing the<br />
structural guidelines for better performance in partial<br />
overlap impact.<br />
Figure 13 shows the undeformed mesh of a frontal<br />
impact with partial barrier overlap, and Figure 14 shows<br />
the deformed shape at 50 msec after offset impact. Whcn<br />
compared with the deformed shape under full frontal<br />
impact shown in Figure 2, there are apparently large<br />
Sectlon 3: Txhnlcal $esslons<br />
Figure 13. Undeformed Mesh: Offset lmpect<br />
Flgure 14. Delormation at 50 msec After Ollset lmpact<br />
differences in the deformed shape of the front end body<br />
structure.<br />
Rear Impact<br />
For the case of rear impact, the experiment quite often<br />
uses rear moving barrier impact. Figure l5 represents a<br />
FEM model fbr this particular impact. In this calculation<br />
and associaled experinrent, one must not only be<br />
concerned with minimizing the deformation of the rear<br />
compartment, but it is also important to protect the fuel<br />
tank from lea-kage resulting from the exccssive<br />
deformation of the rear portion of a car body.<br />
Figure l6 shows the deformed shape at 50 msec after<br />
impact. In this calculation, the kinctic energy of the<br />
r85
lSth lnternetlonal Technlcal Contarence on Experlmental Satety vehlcles<br />
Flgurc 15. Undelormed lfeshr Rear iiovlng Barrier lmpact<br />
Figure 16. Deformation 8t 50 msec Afler Rear iloving<br />
Barrier lmpact<br />
moving barrier having a mass of 1,800 kg is absorbed<br />
relatively well through the deformation of the rear car<br />
body. The initial velocity of the rear moving barrier was<br />
taken as 50 km/tr. In order to have better correlation<br />
between rear moving barrier impact calculation and the<br />
experiment, it was found that proper modeling of the rear<br />
suspension and the rear axle is a key element.<br />
Side Impact<br />
Very recently, computer simulation of side impact has<br />
been studied by several researchers and structural<br />
analysts.(laxlt) This movement is motivated by the fact<br />
that milny efforts have, over the years, been undertaken<br />
in Europe and the United States to define safety<br />
standards for side impacts. Under the proposed side<br />
impact testing procedures-depending upon the organization<br />
involved-a deformable barrier made from<br />
aluminum honeycomb or polyurethane foam is required.<br />
186<br />
This means that in the experiment, the deformable<br />
barrier must be replaced each time. This results in<br />
additional work for the testing engineers. Thereforc, the<br />
benefit of the type of simulation described in this paper<br />
is obvious. Once a model of the deformablc moving<br />
barrier is completed, it can be repeated used.<br />
The authors started side impact calculations in 1988.<br />
Unfortunately, computer capacity was not enough to<br />
execute the full-scale side impact calculation at that<br />
time. Since then, due to improvements in both computer<br />
performance and the FEM code (DYNA3D), side impact<br />
calculation are now realistic. Figure l7 shows a typical<br />
FEM model of side impact calculations that has been<br />
evaluated by the authors for several months. As the<br />
reader may see, in Figure 17 a finer mesh is used, and<br />
the front and rear seats are also modeled. This is in an<br />
effort to get a better correlation between the calculations<br />
and experiments in terms of car body deformation.<br />
Figure l8 shows the deformed shape at 50 msec after<br />
impact. These calculations took about 8 hours of CPU on<br />
a HITAC 820/60.<br />
Flgure 17. Undeformed Mesh: Side lmpact<br />
Figure 18. Deformation at 50 msec After Side lmpact<br />
The authors feel that further study of side impact<br />
calculations is needed to get a better corrclation between<br />
calculations and experiments. One of the areas in which<br />
an improvemcnt is required is a means of modeling and<br />
calculating the friction forces exerted between the<br />
ground and the tires. Another area for improvement is<br />
the modeling of the front and rear seats. These components<br />
are structurally complicated. If a faithful model<br />
of the seats is used. the increase in the number of the<br />
FEM element$ increases results in a very large CPU<br />
time. On the other hand, if a coarse simple model is<br />
used, accuracy is sacrificed to a certain extent. In this
egard, additional studies should be conducted on side<br />
impact simulation.<br />
There is another recent research area of sidc impact<br />
simulation. H. Lupker et al.(r6) studied occupant kinematics<br />
simulation of side impact using MADYMO. There<br />
was no detailed discussion on how to model an occupant<br />
and a car body using this code, but the combination of<br />
DYNA3D with codes such as MADYMO. CAL3D or<br />
MVMAZD may be a promising of approach to evaluate<br />
integrated side impact performance of a vehicle.<br />
Bumper Impact<br />
As a final example of crashworthiness calculation,<br />
consider Figure l9 which simulates a bumper attached to<br />
the front (rear) of the automobile body subjected to<br />
impact by a pendulum having the same weight as the<br />
vehicle. Figure 20 shows the deformed configuration of<br />
the bumper at 30 msec after the pendulum touches the<br />
vertical fascia of the bumper. Not onty can onc calculate<br />
the configuration of the bumper deformation as a<br />
function of time, but also the history of the force exerted<br />
on the structural body frame and the kinetic energy<br />
absorbed by the bumper as shown in Figure 21.<br />
Information obtained through such calculations as the<br />
force transmitted to the bumper attachment and the<br />
energy absorbcd by dcformation of the bumper could be<br />
very useful in the early stage$ of the car body structurll<br />
dcsign proce$s.<br />
Figure 19. Undeformed Mesh: Bumper tmpact<br />
Conclusion<br />
Several examples of automobile crashworthiness<br />
calculations have been introduced and discussed. Thcse<br />
calculations were performed for the purposc of investi-<br />
Sating not only the possibility of simulating the<br />
dcformation o[ car body though various impact configurations<br />
in dctail with thc aid of the FEM code<br />
DYNA3D and a supercomputer, but also thc cffcctiveness<br />
of the computer simulation technique for designing<br />
an integrated car body structure for crashworthiness.<br />
This study demonstratcs that, information cfln be<br />
obtained from the calculations, which agreed both qualitatively<br />
and quantitatively with experiments, and that the<br />
$ectlon 3: Technlcal $esstons<br />
Flgure ?0. Deformatlon at 30 msec Aft6r Bumper lmpact<br />
10<br />
GI<br />
P B<br />
x<br />
E e<br />
z- 4<br />
g o<br />
fi2<br />
0 2 0 4 0 6 0 8 0<br />
Tlme (msec.)<br />
FlEure 21. lmpact Energy Absorbed by Bumper as a<br />
Function of Time<br />
100<br />
results obtained can be used to support the design of an<br />
integrated car body structure in terms of crashworthiness.<br />
The application of crashworthiness computer simulation<br />
is best used in the early stages of body structural<br />
design where there is a relatively large degrec of<br />
freedom to modify the dcsign. In other words, the<br />
effectiveness of colnputer simulation technique likely<br />
will bc best rcalized when it is used as a tool to<br />
exteriorize design concepts and idcas at an early stage of<br />
the body structural design on the assumptions thflr; (l) it<br />
will be effective in reducing the time and the procedures<br />
for development and design work through the application<br />
of this simulation technique, (2) ir has been established<br />
that there is a rcasonable level of accuracy in this<br />
simulation technique, and (3) a lot of time preparing<br />
calculation model is not required.<br />
Unfortunately, these three prerequisites are not always<br />
satisfied with thc present sirnulation tcchnique. Particularly,<br />
there should he considcrable improvement in<br />
preparing a calculatiolr model. Sinrply stated, there is a<br />
qurlitative gap between CAD data and FEW mesh data.<br />
At present, the hridge to cross this gap is mainly duc to<br />
man-power (analysts and/or modelers). This is the area<br />
that needs to be improved. Nevertheless currently the<br />
simulation technique actually has the advantage of<br />
187<br />
t,i<br />
ii
13ffi lnternatlonal Technlcal Conterence on Experimental Safety Vehlcles<br />
reducing the cycling process of crashworthiness experiments<br />
on actual vehicles.<br />
The authors feel that work should be continued to<br />
improve (1) calculation model preparation, (2) calculation<br />
accuracy associated with modeling tcchniqucs, and<br />
(3) the softwarc code and computer perfbrmance. Such<br />
efforts are still cssential in order to extend the simulation<br />
technique to car body structural design and integrated<br />
crashworthiness performance in final pact of the second<br />
stage of crashworthiness simulations. The third stagc of<br />
this study, will involve coupling of the technique<br />
presentcd here with occupant kinematics simulation,<br />
which will be an important major accomplishment.<br />
References<br />
(1) 1989 Traffic Accident Report, All Japan Traffic<br />
Safety Association.<br />
(2) J. O. Hallquist,<br />
"Theoretical<br />
Manual of DYNAJD,*<br />
LLNL, Rept. UCID-19401, 1982.<br />
(3) J. O. Hallquist and R. G. Whirley, *DYNAiD<br />
User's Manual," LLNL, Rept. UCIDI9592, Rev.<br />
5.<br />
(4) J. O. Hallquist and D. W. Stillman, "L.S-DYNAJD<br />
Course Note.," LSTC. 1990.<br />
(5) M. Igarashi, et aI., "Application of DYNA3D to<br />
Large-Scale Crashworthiness Calculations," L of<br />
the Society of Auto. Engineers of Japan, Vol. 40,<br />
No. 11, 1986.<br />
(6) K. Shimomaki and M. Igarashi, "Large Stale<br />
Crashworthiness Calculations in Autontohile and<br />
Its Future Trend," lEth <strong>Int</strong>ernational Symltosium<br />
on Automobile Technology & Automation,<br />
Florence, Italy, May-June, 1998.<br />
(7) D. Vander Lugt, ct al., "Passenger<br />
Car Frontal<br />
Barrier Simulalion Using Nonlinear Finite Element<br />
Methods," SAE paper 871958.<br />
(8) T. Sakurai, et al., "Crash Anulysis on Passenger<br />
Cars," J. of the Society of Automotive Enginccrs<br />
of Japan, Vol. 4?, NO. I0, 1988.<br />
(9) T. Scharnhorct,<br />
"FFM Crash-A Supertomputer<br />
Application," SAE papcr 880897.<br />
(10) B. Shkolnikov, et al., "On Analytical Approaches<br />
in Crash Simulation," SAE papcr 891975.<br />
(11) L. Nilsson,<br />
"Computational<br />
Crash Analysis at the<br />
Saab Car Division," l2th <strong>Int</strong>ernational Tcchnical<br />
<strong>Conf</strong>ercnce, <strong>ESV</strong> Goteborg 1989.<br />
(l?) E. Schelkle and R. Remensperger,<br />
"lntegrated<br />
Occupant-Car Crash Simulation with the FEM:<br />
The Porsche Hybr:d III-Dummy and Airbag<br />
Model," SAE paper 910654.<br />
(13) L. Grosch, et al., " Safety Performance of<br />
Passenger Cars Designed trt Ar:commodate Frontal<br />
Impacts with Purtial Barrier Overlap," SAE paper<br />
890748.<br />
(14) K. Gruber, eI al., "Computer Simulation of Side<br />
Impact Using Different Mohil Barriers," SAE<br />
paper 910323.<br />
(15) K. Taga, ct al., "I'he Application of Super<br />
Cttmputer Ftttused on Safety Developme.nt,"<br />
Superconrputing Japan 9I <strong>Conf</strong>erence, Feb. 1991.<br />
(16) H. A. Lupker, et al., "Arlvrz<br />
nt:es in MAL)YMO trash<br />
simulatittns," SAE papcr 910879.<br />
st.w.26<br />
Crash Pulse Recorder (CPR)-Development and Evaluation<br />
of a Low Cost Device for Measuring Crash Pulse and Delta-V<br />
in Real Life Accidents<br />
B. Aldman, A. Kullgren,<br />
A. Lie, C. Tingvall<br />
Folksam Research and<br />
Chalmers University of Technology<br />
Abstract<br />
The importance of accident reconstruction and analysis<br />
is fundamental. Accidcnt scvcrity can be measured in a<br />
variety of ways, but in fronl.al collision lhc change of<br />
velocity (aV), mean acceleration and crash time duration<br />
arc most often used. aV and mean acceleration are<br />
estimatcd from vchiclc damages. It is however known,<br />
that these estimates are poor if comparcd to laboratory<br />
test conditions. In order to incrcasc the possibilities to<br />
evaluate real life accidents in thc futurc, on board<br />
measurements is an effective techniquc. In this presentation,<br />
a new device aimed at mcasuring the crash pulse in<br />
188<br />
real life accidents. is descrihed. The device. callcd Crash<br />
Pulsc Rccordcr (CPR), is a low cost spring mass system<br />
including a photographic tcchniquc. In the presentation,<br />
the constructi()n as well as the output, perforrnancc and<br />
reliability are given.<br />
Background<br />
Accident data collection concerns several important<br />
parametcrs. Most of thc material today is collected by<br />
untrained peoplc as a secondary task and will theretbre<br />
be poor with low precision. One paramctcr of ccrtain<br />
intcrcst is the severity of an accident. Often is the<br />
accidcnt severity calculated by accident reconstructions<br />
where aV, changc ol' velocity, is the most often used<br />
paramctcr. Such calculations gives a random error of<br />
around lsEo (l). Another way to take carc of the<br />
accidcnt severily is by indirect statistical rnethods (paircd<br />
comparisons (3)). The accident severity is cssential for
several reasons. Both concerning accident severity<br />
distribution and also injury risk as a function of accident<br />
severity. The relation between risk of injury and severity<br />
can be seen as a dosc response problcm where the dose<br />
is the severity of the crash and the response is the injury<br />
of the occupant in the accident.<br />
p(i)<br />
1.0<br />
0,0<br />
'<br />
random emr whcn measurc of injury riEk<br />
rundom ercr when ,fl<br />
ttreasure of accidcnt scvcrity<br />
Accideni severity (s)<br />
Figure 1. Schematlc Probability Functions for Inlury Risk<br />
for Different Accident S€verity<br />
q(s) rcfcru to construction (1) and t (s) to<br />
construction (2).<br />
At low severities no injuries cccur and at a certain<br />
level thc risk is l00%o, The figure also shows error<br />
estinrates both concerning biological variation and<br />
variation concerning the severity mcasurements. For<br />
mcasurements of the severity of injurics many $ystems<br />
are existing (AIS etc).<br />
In most cases the accuracy of accident severity is to<br />
low to be able to detect changes in safety levels. The<br />
error intervals is greater than the changes in safety<br />
levels.<br />
The ultimate data available would of course be<br />
idcntical measurement precision of the dose as in<br />
laboratories, i.e- the whole acceleration time history for<br />
the crash.<br />
This paper describes fl crash recorder with the main<br />
purpose of producing aV estimations. It is a low cost<br />
one dimensional accelerometer which can register the<br />
acceleration time history, though with a lower precision<br />
and a lower sampling frequency than an accelerometer<br />
for laboratory use. The loss of precision of aV<br />
estimations will be under five percent.<br />
Description and Mathematics<br />
General description<br />
The accelerometer in this case, called Crash Pulse<br />
Recorder (CPR) (see fig 2), is based on a spring mass<br />
system where the movements of the mass in a collision<br />
is measured. It includes mechanical, elcctronic and<br />
optical featurcs. The quote spring coefficient over the<br />
mirss, is chosen in that way so the time for the displacement<br />
of the mas$ takes a littlc bit longer time than a<br />
normal crash takes in time. It means that around 120 ms<br />
will be registered depending of the shape of the crash<br />
pulse.<br />
#,r '.<br />
w r *<br />
ffir'<br />
4.<br />
Ft,'<br />
ffi<br />
k*me<br />
'{xr\{'!<br />
Sectlon 3: Technlcal $essions<br />
1"/<br />
Figure 2. Crash Pulse Recorder (CPR)<br />
\<br />
Ftr '<br />
The displacement of the mass is registcred on a<br />
photographic film (Fig 3), where a light emitting diode<br />
(LED) registers its location. The LED is driven by a<br />
crystal oscillator circuit which gives a modified square<br />
pulse with a frequency of 1000 Hz. The circuit has its<br />
own power cell and docs not need an external power<br />
unit. The power cell is of lithiurn type flnd can be<br />
inactive for several years and then give the accuratc volt<br />
level when the circuit is activated. Thc temperature<br />
stability of the lithium cell is also very good in the<br />
actual temperature range (-30'C to +50oC). The circuit<br />
is activated via a micro switch whcn the mass starts to<br />
move in a crash. The trigger level is chosen to be<br />
approximatcly I g to avoid registration of maneuver<br />
decelcration.<br />
How to lake tare of a registration alter a trash<br />
After an impact the registrations on the photographic<br />
film (Fig 3) is scanned into a computer as a digital<br />
image. A computer program finds the greylevel ccntcr of<br />
gravity for cach mark. From these mcasurements it is<br />
possible to gct the displacement of thc mass as a<br />
function of time. With all characteristic parameters for<br />
the CPR measured and with the displacement time<br />
history the acceleration time history is calculated with<br />
the mathematics presented below. To take care of thc<br />
errors in the measurements of the registrations on the<br />
photographic film the displacement curve is filtered with<br />
a frequency of 50 Hz.<br />
Mathematic.f<br />
x = displacemcnt of the tube relatively a fixed point<br />
s = rclative displacement of the mass<br />
fi = il*" + m,r,,,,,*/Z = Cquivalent maSS fOr the system<br />
c = dampinB coefficient for the system<br />
k = constant for the spring<br />
Fo = prcstress force of the spring<br />
Fu = frictional drag<br />
The coordinate system chosen for the calculations is<br />
described in Fig 4, where x and s are described irbove.<br />
rllir<br />
r89<br />
ir<br />
;i<br />
j<br />
,j<br />
1t<br />
-j<br />
-;<br />
;i<br />
''<br />
i<br />
,i
13th <strong>Int</strong>ernatlonal rechnlcel conference on Expertmentet safety vehtctes<br />
* ****t<br />
Figure 3. Dlsplacement Hegistratlon of the CPR on a Photographic Film<br />
_______<br />
Flgure 4. Schematic Picture of Coordinate System for the<br />
Mathematic ltrbdel of the GPR<br />
The relation between the force of inertia and the<br />
external forces acting on the mass is shown in cquation<br />
1. Included are terms for spring force, viscous damping,<br />
prestress force and frictional drag.<br />
m(s"+x*') = - Cs' - ks - Fo - F,<br />
x" = - s" - c/m s' - k/m s - (Fo - Fr)/m<br />
s' = ds/dt<br />
$'*=ds'/dt=d?s/dtz<br />
*<br />
.*<br />
eql<br />
eq2<br />
eq3<br />
eq4<br />
x'* is the acceleration pulse for the tube and by that the<br />
accelcration pulse for the car if the tube is tixcd to the<br />
car.<br />
The initial conditions in this case are<br />
x(0) = s(0) - 0,x'(0) = s'(0) = aV<br />
Comparison Tests Between Accelerometer<br />
for Laboratory Use and CPR<br />
Several tests was made on a sled crash testing track to<br />
see the accuracy and precision of the CPR both<br />
concerning the shape of the acceleration pulse and also<br />
the change of velocity and mean acccleration. The<br />
displacement curves was meflsured and the acceleration<br />
for the sled was calculatcd. The displacement curve for<br />
the spring mass system in the CPR in test F51 is shown<br />
in Fig 5 and the accelerations pulsc from the CPR and<br />
the accelerometer in the same test is presented in Fig 6.<br />
The acceleration pulses was dividcd in three different<br />
parts and the change of velocity and mean acceleration<br />
for each part was calculated. In Table I the results from<br />
three tests, F49, F50 and F51, are presented. The<br />
accuracy for the total change of velocity in the tcsts were<br />
all under 3 percent.<br />
;<br />
0 20 ,+0 60 80 l(xl 120<br />
Figure 5. Displacement CuruB for the CFR in Test F 5t<br />
g<br />
')()<br />
I tar.<br />
-/<br />
Figure 6. Gomparison Between Acceleration Pulse lor thE<br />
CPR and an Accelerometer in Te$t F 51<br />
r00<br />
Table 1. Results from Te$ts F49, F50, and F51<br />
test F49<br />
tot 47,7<br />
0-30 ms 14,0<br />
30-60 ms 18,3<br />
6()-90 ms 14,1<br />
test F50<br />
tot 48,3<br />
G30 ms 14,6<br />
3G60 ms 18,3<br />
6G90 ms 13,8<br />
test F51<br />
tot 49,0<br />
G30 ms L3,7<br />
3l)-60 ms 16,9<br />
6G90 ms 16,2<br />
t It/ \<br />
Accelerometer values<br />
Av(km/h) acc-mean(g)<br />
13,0<br />
13,?<br />
17,:l<br />
13,3<br />
13,5<br />
13,8<br />
I/,J<br />
13,0<br />
\/ \ I<br />
_\<br />
\<br />
Arn \t<br />
CP<br />
I h I<br />
\I<br />
r<br />
CPR-values<br />
Avftm/h) acc-mean(g)<br />
49,0 12,5<br />
t2,2 11,5<br />
r7,r 16,1<br />
16,2 15,3<br />
48,9<br />
T2,L<br />
L7,9<br />
15,9<br />
49,1 12,4<br />
12,3 11,6<br />
16,6 15,7<br />
16,2 15,3<br />
\
Discussion<br />
Accident severity estimations based on accident<br />
reconstruction have several drawbacks. The reconstruction<br />
is based on deformations of the car, mass, stiffness,<br />
direction of force in the crash etc. Deformation measurements<br />
are often made by hand which gives an accuracy<br />
of 17,5 cm (l). The estimations of the angle of the crash<br />
are done with an accuracy of J20 degrees (l). This leads<br />
to an average accuracy of around tl|Vo of the aV<br />
computation (l) in an idealized case with collisions made<br />
in laboratory. It can be expected that the error in real life<br />
is even larger, up to 20-30%, To detect the change in<br />
safety level of a new safety system or a new car with<br />
that accuracy of accident severity is impossible when the<br />
difference in safety level is moderate but still important.<br />
A problem is that poor accident data will result in an<br />
inaccurate answer even if a large data material is<br />
collected. Measurements with low accuracy can not be<br />
replaced with more data (2). A simple analysis of the<br />
influence of measurement errors and their effect in a<br />
comparison between accident severity and risk of injury<br />
was made in ref (2). Thc model used was a simplc linear<br />
model, y=a+bx, where a was the intercept and b the<br />
slope. In Table 2 it can be seen that the regression<br />
coefficient, where the error is 3OVo,is reduced by more<br />
than 507o. The possibility to draw conclusions from the<br />
data material coltected is by that affected as the relation<br />
between what can be detected and the measurement error<br />
is highly affected.<br />
Table 2. Regrersion Coellicisnts (a tor intercePt and<br />
b for slope) and Amount of Varlance Explained (R') by<br />
e Simple Llnear Model (y = a + bl whsre x is sublect<br />
to meaturement srrors of 0, 10, 20 and 30%.)<br />
pararrreter<br />
0%error l0%error 2fffierror 30%error<br />
a<br />
b<br />
2.23<br />
10.6<br />
26.3<br />
1.93 1.67<br />
0.El<br />
t(b) 65.7 18.5 9.5<br />
p2 o.9B o.Bb 0.6l<br />
38.8<br />
6.4<br />
0.41<br />
It can be discussed what should be measured and what<br />
accuracy is needed. Kurimoto et al. (4) have made<br />
comparisons of occupant response for different shape of<br />
crash pulses. In that study the shape of a crash pulse was<br />
made by approximated trapezoids. The crash pulse was<br />
built by two trapezoids with different acceleration levels.<br />
It can be seen that the difference in occupant displacements<br />
between pulses using approximated trapezoids and<br />
the original pulse was very small. It is also analyzed how<br />
small variations of g level and deformation of each<br />
trapezoid in the approximated pulse results in large<br />
variation to the dummy parameters, HIC and chest g.<br />
The study shows that it is not enough to have thc total<br />
change of velocity to comparc with injuries. It also<br />
Sectlon 3: Technlca, Sessrons<br />
shows that it is enough to $plit the pulse in a few<br />
diffcrent parts and know the change of velocity and the<br />
time duration for each part to be able to discriminate<br />
bctween pulses.<br />
Another study made by Hartemann et al. (5) shows<br />
that intrusion affects the injury and fatality rate very<br />
much. To measure only aV or other parametcrs as mean<br />
acceleration is not enough to relate to injury and fatality<br />
rates. Deformation measurements, especially interior, is<br />
therefor essential.<br />
In order to make large fleet field experience with<br />
crash recorders it is essential that thc cost for each unit<br />
and its installation is low, With the CPR presented in<br />
this paper it is possible to, in retrospect, calibrate it and<br />
measure all the parameters necessary for the analysis.<br />
The production cost can therefore be rcduced<br />
dramatically.<br />
The presented recorder will in relation to other<br />
proposed recorders (8,9), only measure variations, that<br />
are fairly insensitive to thc integrity of the driver. The<br />
change of velocity is only one part of the accident<br />
process. The aim for the CPR described in this paper<br />
was that it should be able to detect the mcan acceleration<br />
levels for at least thrcc different parts in the pulse. The<br />
time duration and aV will also bc included. It is<br />
optimizcd for measuring collisions with a aV of around<br />
50 km/h. The maximum aV possiblc is around 60 km/h.<br />
In a study made by Otte (6) it can be seen that ovet 95Vo<br />
of all collisions occur with aV undcr -50 km/h. At aV of<br />
60 km/h ttver 99Vo of all collisions is covered.<br />
The method used for this purpose is to measure the<br />
displacement of the mass in a spring mass system in an<br />
impact. The acceleration pulse is then calculated in<br />
retrospect with the CPR calibrated and all adcquate<br />
parameters measured.<br />
One drawback witn using photographic film as<br />
registering media is that there is a limit concerning<br />
frcquency of the LEDs to be registered. If using<br />
magnetic tape and tape recordcr head instead it is<br />
possible to havc ntuch higher frequency. The major<br />
reason for choosing the photographic film is low cost' To<br />
be able to detcct all points on the photographic film it is<br />
essential that all points ire very small and sharp. The<br />
Iight in the CPR is thereforc passing small holes in the<br />
mass with a diameter of a l0th o[ a mm.<br />
It is essential that the measuretnents of the registrations<br />
on thc photographic tilm has very high precision'<br />
There will of ct.rursc be errors whcn measuring thc<br />
registrations on the photographic film, even if they are<br />
minimizcd, therefore the displacement curvc is filtered<br />
before making calculations of the acceleration pulse.<br />
For several reasons the mass has a relatively large<br />
lateral space. The major reason is that it otherwise would<br />
be very difficult to measurc all points whcn the points<br />
from the mass on its way back would be on the same<br />
vertical line as the points on its way out. Another reason<br />
is for minimizing thc darnping effects which otherwise<br />
19l<br />
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would be considerable. It is also possible to measure the<br />
main direction of force in the crash in a t5 degrees<br />
range from full frontal impact.<br />
A drawback with the CPR is that it only can measure<br />
the acceleration levels in one direction. Still it is useful<br />
for a large proportion of all collision typos in real life<br />
accidents. A result from the study made by Otte (6) is<br />
that 507a of all impacts are frsntal impacts, and from<br />
these around 65Vo is in the angular range for the CPR.<br />
Also a small part of lateral collisions can be measured<br />
with the CPR. In total at least 407o of all collisions can<br />
be measured with the CPR. The figure 507o frontal<br />
impact is though a little bit lower than results from other<br />
studies in the area.<br />
To be able to also take care of lateral impacts and rear<br />
end collisions it is of coursc possible to let the mass be<br />
held by three springs in a large square box, or to install<br />
CPR in several different directions. For side collisions,<br />
the change of velocity for the struck car is, however, of<br />
interest in assessing the severity of a side impact to the<br />
occupant (7). In this projcct the aim was to analyze<br />
mainly frontal impacts as a first step.<br />
The te$ts madc to verify the accuracy and prccision of<br />
the cPR showed that the flccuracy for the total av of the<br />
crash were under threc percent for all tests. The shapc of<br />
the acceleration pulses in fig 6 is also very similar, the<br />
g-levels is in the same region and also the time duration.<br />
The tests were all trolley or sled tests where the shape of<br />
the acccleration pulse was similar for all tests and the<br />
shape were very rectangular. Full scalc tests will be<br />
made, both barrier tests and car to car tests, to see the<br />
performance of the CPR in other types of acceleration<br />
pulses. A large scale field experience will be pcrformed<br />
during next year with 20.000 units.<br />
Conclusions<br />
. By specifying the necessary precision in accident<br />
severity asses$ment, a low cost crash recorder (CPR)<br />
was developed.<br />
. The output from the CPR can be used to calculate<br />
change of velocity, pulse duration and simplified<br />
pulse shape (as well as mcan deceleration).<br />
References<br />
l. R A Smith, T Noga, Accuracy and sensitivity of<br />
CRASH, In: proceedings of rhe 26th Stapp Car<br />
Crash <strong>Conf</strong>erence 821 169. 1982.<br />
, Kamren B, v Koch M, Kullgren A, Lie A, Nygren A,<br />
Tingvall C, Advanced accident data collectiondescription<br />
and potentials of a comprehensive data<br />
collection system, accepted for publicarion at the<br />
<strong>ESV</strong> confcrcnce 199I.<br />
3. Gustafsson H, Hagg A, Krafft M, Kullgren A,<br />
Malmstedt B, Nygren A, Tingvall C, Folksam Car<br />
Model Safety Rating 1989-90.<br />
4, Koji Kurimoto, Koji Taga, Shigeru Haruna, Hiroyuki<br />
Matsumoto, The evaluation of the-influcnce of<br />
vehicle crashworthiness and interior parts on<br />
occupant injury, In: proceedings of the Stapp Car<br />
Crash <strong>Conf</strong>erence 892009, 1989.<br />
5. F Hartemann, J Y Foret-Bruno, C Henry, G<br />
Faverjon, C Got, A Patol, J C Coltat, The<br />
characteristics of frontal impacts in real world<br />
accidents, In: proceedings of thc <strong>ESV</strong> conference<br />
1987t 424-431.<br />
6. D Otte, Comparison and realism of crash simulation<br />
tests and real accident situations for the<br />
biomechanical movements in car collisions, In:<br />
proceedings of the Stapp Car Crash <strong>Conf</strong>erence<br />
902329,1e90.<br />
7. Kamren B, Kullgren A, Lie A, Tingvall C, Side<br />
protection and child restraints-accident data and<br />
laboratory test including new test methods, Accepted<br />
for publication at the <strong>ESV</strong> conference 1991.<br />
L Wilkie K, Baird B, Millcr C, The inexpensive crash<br />
recorder project, technical rcport from Synergetic<br />
Engineerin g Associates.<br />
9. Kock M, Salomonsson O, Crash recorder for safety<br />
system studies and as a consumers product, In: SAE<br />
SP 852, Frontal crash safe technologies for the 90's,<br />
199 t.<br />
st.w.27<br />
An Overview of the Vehicle Inspectorate'$ Database on Bus, Coach<br />
and Goods Vehicle Examinations Following Major Accidents<br />
Donald Macdonald<br />
Department of Transport Vehicle Inspectorate<br />
Accidents, Defect and Recalls Branch<br />
Abstract<br />
The Department of Transport's Vehicle Inspectorate<br />
examines approximately I,800 accident involved vehicles<br />
L92<br />
each year to establi$h whether vehicle condition contributcd<br />
to the cause of the accident. The majority of<br />
these vehiclcs are heavy goods vehicles (HGVs), buses<br />
and coaches. The information may be used by the<br />
Vehicle Inspectorate to investigate vehicle safety defects<br />
of a design or manufacturing nature. The information<br />
collected from the vehicle examinations is coded and<br />
entered onto a computer databasc.
This paper describes how the information is collected,<br />
coded and subsequently used to identify vehicle safety<br />
concerns or to provide information used in lormulating<br />
government policy, The strengths and limitations of this<br />
method of collecting and analysing this data are<br />
described and examples used to illustrate these.<br />
Lessons learned about data collection, coding, and<br />
accessing of the information are included. Future<br />
development of all these areas is described in the paper<br />
including the move to place greater emphasis on the<br />
secondary safety aspects of vehicle examinations.<br />
fntroduction<br />
Responsibility for the safety of road vehicles is split<br />
within the Department of Transport between the Vehicle<br />
Standards and Engineering Division (VSE), the Vehicle<br />
Certification Agency (VCA) and the Vehicle Inspectorate<br />
(VI). The last two of these have recently been constituted<br />
as Executive Agencies. VSE is responsible for<br />
policy and legislation of vehicle construction standards,<br />
VCA for type approval of vehicle types between national<br />
and EC standards and VI for roadworthiness testing and<br />
enforcement.<br />
The roadworthiness checks include statutory tcsting of<br />
heavy goods vehicles (HGVs) at 93 VI test stations,<br />
initial certification and statutory testing of buses and<br />
coaches, monitoring of the car test scheme at 17,000<br />
independent authorised premises throughout the United<br />
Kingdom (UK), roadside spot checks on vehicles and<br />
detailed vehicle inspection following accidents (l).<br />
During each of the last three years Lhere have been an<br />
average of 1,800 such post accident inspections carried<br />
out by VI staff. Reports on these are checkcd, coded and<br />
entered on to a computer database for future analysis.<br />
Collecting the Data<br />
Thc majority of road accidents are attributable to<br />
human error rather than a vehicle defect although very<br />
often a driver claims that a defect caused the accident<br />
rather than admitting his own enor. It is therefore<br />
important to establish at an early stage if the condition<br />
of the vehicle contributcd to the accident in any way to<br />
enable.appropriate action to be taken either against the<br />
drivcr or the owner of the vehicle.<br />
Although police forces are able to inspect smaller<br />
vehicles involved in accidents they do not always have<br />
the necessary skills and rcsources to examine HGVs,<br />
buses and coaches. In the case of these vehicles, if the<br />
driver alleges a vehicle defect or the police suspect a<br />
defect was contributory to the cause of the accident, thcy<br />
will request that an inspection of the vehicle is carried<br />
out by a VI Vehicle Examiner. In addition VI may<br />
examine vehicles if thc accident has a particular interest<br />
for the Department of Transport.<br />
The inspection covers the primary safety systems on<br />
the vehicle including brakes, steering, tyres, suspension,<br />
lights, transmission and bodywork. The Vehicle<br />
Sectlon 3: Technlcel Sessions<br />
Examiner completes a written report which includes<br />
operator details, accident circums[ances and information<br />
on any defects found during his inspection. It is these<br />
reports which are used to produce the VI computer<br />
database. In addition the police receive a statement on<br />
the condition of the vehicle which may be used to<br />
support prosecution action. If a Vehicle Examiner<br />
considers it necessary a prohibition notice will also be<br />
issued to prevent the vehicle being used until it has been<br />
repaired. Prohibitions are recorded on the operators file<br />
and may influence the granting of an Operators Licence.<br />
Vehicle Examiners are also encouragcd to comment on<br />
the performance of secondary safcty items-seats, seat<br />
mountings, restraint systems, door locks and safety glass.<br />
Any items or systems liable to increasc the risk of injury<br />
to vehicle occupants or other road users involved in the<br />
accident should be included in the Vehiclc Examiners<br />
accident report. Examples of these include hostile<br />
interior fittings, seat belt performance, fircs, crashworthiness<br />
of the vehicle structure and possible evacuation<br />
problems from an accident darnaged vehicle.<br />
Compiling the Database<br />
From 1982 onwards all reports sent to VI headquartcrs<br />
havc been coded and entered on a computer database.<br />
This database now holds in excess of 15,000 records.<br />
The average annual number of reports ovcr the last three<br />
years is 1,800 and the types of vehicle inspected are<br />
shown below (Table l).<br />
Table 1. Vehicle Types Inspected by Vl Vehicle<br />
Examiners<br />
Ysar Gooda v€hicldB Buge6 and Coachss other6 Total<br />
198 I<br />
1949<br />
1990<br />
961<br />
969<br />
1089<br />
634<br />
720<br />
775<br />
95<br />
85<br />
a8<br />
1690<br />
L774<br />
r952<br />
Initial coding of the accident circumstances, casualties<br />
and vehicle identification is an administrative task,<br />
which is followed by technical coding by a VI engineer.<br />
All codes used for this exercise must conform with those<br />
set out in the VI coding manual. Any mechanical<br />
deficiencies found with the vchicle attributablc to<br />
inadequate milintenance ot defects in design and<br />
manufacture are codcd under subject headings, and sub<br />
coded to a further three stages where appropriate. In<br />
gencral accident damage is not coded for primary safety<br />
defects, but is coded for secondary safety defects. For<br />
examplc tyre deflation duc to the impact would not be<br />
codcd, but failure of a seat mounting in an accidcnt<br />
would be coded as body, seat, mounting, fix.<br />
Data Analysis<br />
Any safety defects identified on the vehicle which<br />
may be attributflble to dcsign or manufacturing<br />
deficiencies are investigated with the vehicle manu-<br />
193<br />
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lSth lnternatlanal Technlcal conference on Expertmentel safety vehtctes<br />
facturer. This investigation may result in the issue of<br />
service information, a design change for future vchicle<br />
builds or recall to enable modifications to be made to<br />
vehicles already in service. It is important to search the<br />
datflbase for related cases to determine if an incident is<br />
isolated-perhaps due to the severity and nature of the<br />
accident, or is one of a number of similar occurrence$.<br />
Comparison of the performance of peer group vehicles<br />
can also be used to indicate if one manufacturers vehicle<br />
performs better than another in similar circumst:ances.<br />
The database can also be used to identify particular<br />
groups of vehicles or accident features. Examples of<br />
these include occupant ejection from buses and coaches,<br />
or afiiculated vehicles in jack knife accidcnts. By<br />
looking at the hard copies of the accident reports it is<br />
possible to determine ejection routes, glazing security<br />
failures, door opening mechanisms, or incompatibility of<br />
tractor trailer combinations. The results of such analysis<br />
may be used to support the case for legislative changes,<br />
or may indicate an area of work which requires further<br />
investigation. Typical examples are given below.<br />
On some coaches the roof hatches are also used as<br />
secondary emergency exists in the event of a vehicle<br />
rollover. Incorrect operation of the handles by a<br />
pas$enger on one of these hatches as the coach was<br />
being driven along caused the hatch to detach from the<br />
vehicle. After consultation the manufacturer agreed to<br />
offer a service fix to operators by fitting an extra<br />
securing strap and improving the markings and operating<br />
instructions on the hatch. A sccond hatch detachment<br />
occurred a year later on an unmodified vehicle and in<br />
this case sffuck a following goods vehicle. A second<br />
similar incident with such a small vehicle parc, clearly<br />
indicated the need for further action. The manufacturer<br />
agreed to recall action to ensure that all vehicles were<br />
upgraded to the latest specification.<br />
Examination of incidents of occupant ejection from<br />
buses and coaches via glazed apertures has shown that<br />
these are often associated with people standing in the<br />
vehicle or with horseplay. Poor glazing security, due to<br />
deterioration of gaskets, enlargement of window<br />
apertures or incorrectly sized windows may be<br />
contributory factors. It was therefore viewed as a matter<br />
of concern when it became apparent that a coach<br />
manufacturers bonded windows were becoming insecure<br />
in service. From the manufacturers point of view there<br />
was also a concern about the repair techniques being<br />
used by vehicle operators. The problcm was tackled via<br />
a service action by the manufacturer. A service bulletin<br />
and video were produced with step by step instructions<br />
on how to replace windows and damaged body pancls.<br />
In some accidents it is necessary to make a judgement<br />
on whether a failure is beyond what is considered to be<br />
an acceptable design specification. One such severe<br />
coach accident resulted in virtually all the seats<br />
becoming detached from their mountings, and the seat<br />
frames also breaking allowing the seat backs to come<br />
194<br />
free of the seats. Although there' is currently no<br />
mandatory seat strength requirement for coach seats,<br />
these particular scats were tested to 10g. This is the<br />
proposed European strength requirement for such tcsts.<br />
A search of the VI database showed that such catastrophic<br />
failures are rare, and the manufacmrer confirmed<br />
that this was the most severe accident they had<br />
seen on one of their vehicles. Design improvements were<br />
already in place on current production vehicles and<br />
further improvements are planncd for future builds of the<br />
coach.<br />
Strengths and Limitations of the Database<br />
The Vehicle Inspectorate has trained Vehicle<br />
Examiners at district offices throughout the UK and can<br />
therefore provide complete national coverage. Good<br />
liaison with the police, contacts with all vehicle<br />
manufacturers, and interfacing with other government<br />
departments provides a strong base from which to<br />
invcstigate accidcnts. Where appropriate material<br />
spccialists may be callcd on to determine if a component<br />
failed prior to or as a result of the accident. Since thc<br />
number of occupant casualties in HGVs, buses and<br />
coaches is relatively small, and the Vehicle Inspectorate<br />
specialises in examinations of these vehicle types, the<br />
database contains a significant proportion of all such<br />
accidents in any given year (2) (Table 2).<br />
Tabb 2. Occupants Sufferlng Fatal InJurie3 In HGV$,<br />
Buses and Goaches In Great Britain and Included in<br />
Vl Databass<br />
Ysar HGV<br />
Great<br />
1987<br />
1984<br />
1989<br />
casualties<br />
Britain vr<br />
75 30<br />
73 25<br />
e2 31<br />
Bu6 ahd coach Ca6ualtleg<br />
Great Britain VI Data<br />
1 5 a<br />
L7 tJ.<br />
?0 1A<br />
The accident report form currently used is directed<br />
towards the examination of particular vehicles rather<br />
than the whole accident, and the primary rather than<br />
secondary safety systems on that vehicle. Thc Vehicle<br />
Examiner is asked to provide detailed information on the<br />
operators, driver, accident, circumstances and mechanical<br />
condition of the vehicle. The format of thc form is<br />
biased towards descriptivc text rather than questions<br />
which require an absolute answer. This has the advantage<br />
of encouraging the Vehicle Examiner to provide the level<br />
of detail appropriate to the system being examined, but<br />
can lead to problems of interpretation when the form is<br />
being coded for entry on to the computer database. Care<br />
must be taken when intcrrogating the database to ensure<br />
that all ca$ualties and vehicles in the accident are<br />
identified. As the report form is focused on thc vehicle<br />
itself any information on accident circumstances and<br />
injurics to casualties is of a more limitcd nature. This<br />
information can only be obtained second hand by talking
to the police, vehicle operator or on rare occasions the<br />
driver of the vehicle.<br />
Although a coding manual is used to standardise<br />
makes, models and vehicle deficiencies there are other<br />
coded items which are open to mis-interpretation. It is<br />
sometimes possible to code a vehicle defect in different<br />
ways, so it is imperative that users of the database are<br />
aware of these possibilities. An example is wheel<br />
detachments which may arise from either failure of the<br />
studs and nuts securing the wheel or from bearing failure<br />
where the complete hub becomes detached. lt is therefore<br />
essential to search undcr the subject heading of axles, as<br />
well as wheels, to ensure all detachments are identified.<br />
Not all the information collected on the accident<br />
report form is coded and entered on the database. This is<br />
because the information may only be relevant at a local<br />
level to the Vehicle Examiner-for example in his<br />
dealings with the operator on maintenance issues, or<br />
because it was considercd that analysis on those fields<br />
was unlikely to be necessary. Conversely there is<br />
inlormation coded and entered on the database although<br />
the question is not spccifically asked on the accident<br />
report form. This situation can cause problems for the<br />
engineer coding the information and in doing analysis.<br />
Searches may take more time and need to be much<br />
broader, with reference being made to the hard copy to<br />
establish if the report is relevant or not for the particular<br />
analysis being undertaken. Vehicle weights and seating<br />
capacities are typical cxamples where this may be an<br />
issue.<br />
Although all types of vehicle including bicycles and<br />
caravans are included on the database there are<br />
insutficient numbers of some vehicle categories to do<br />
meaningful analysis. Great care must be taken when<br />
considering the information on cars, caravans, motor-<br />
Sectlon 3: Technlcal Sessions<br />
cycles and other poorly represented vehicle types. Since<br />
therc is also a bias towards vehicles which are alleged or<br />
suspected of being defectivc, it is not possible to draw<br />
conclusions about the state of thc vehicle population as<br />
a whole.<br />
Future Developments<br />
Consideration is currently being given to ways that the<br />
current VI accident investigations and the accident report<br />
form can be improved. One option is to have a tick box<br />
form with multi choice questions which can also be used<br />
as a computer input document. Space would still be<br />
allowed for descriptive text to be added by thc Vehicle<br />
Examiner where appropriate. Another area for consideration<br />
is the amount of secondary vehicle information<br />
collected following different types of accident. ln a<br />
collision with a pedestrian it would be beneficial to have<br />
information on the driver's field of vision, and for HGV<br />
impacts with smaller vchicles the effect or possible<br />
benefit of undcrrun protection would be relevant.<br />
Until such rime as detailed information of this type is<br />
collected it is difficult to quantify the casualty savings<br />
which may ensue from changes to vehicle design<br />
affecting these areas.<br />
In common with many accident databases it is much<br />
easier with hindsight to say what data should have been<br />
collected and what would have been the best way to<br />
arrange the data. It is much more difficult to predict<br />
what will be required in thc future.<br />
References<br />
(l) Vchicle Inspectorate Annual Report.<br />
(2) Road Accidents Great Britain 1989. The Casualty<br />
Report HMSO 1990.<br />
st.w.28<br />
AGeneralApproachtoEstimatingFrontalImpactCo||isionSpeeds<br />
Denis P. Wood<br />
Wood & Associates<br />
Abstract<br />
It is shown that the specific energy absorption<br />
characteristics of the car population in frontal collisions<br />
can be represented by a single equation which has a<br />
coefficient of determination of 0.76. Comparison of<br />
predicted and actual Delta V's when using this relation<br />
shows that the equation yields similar accuracies to<br />
CRASH 3. When the energy absorption characteristics of<br />
individual cars are known the resulting predictions are<br />
superior to both the derived relation and to CRASH 3. A<br />
simple method is derived to estimate the energy<br />
absorption of the missing vehicle when only one of the<br />
collision partners is available for measurement.<br />
<strong>Int</strong>roduction<br />
Various approaches have been developed to estimate<br />
the spceds of vehicles involvcd in collisions from the<br />
permanent crush damage of the vehicles. All centrc on<br />
cstimation of the energy of approach of the vehicles<br />
from the crush damage and the subsequent dctermination<br />
of collision speeds and speed changes from the impactenergy<br />
loss equations.<br />
This approach, originally demonstrated for frontal<br />
collisions in Campbell's classic paper (l), is based on<br />
the assumption of uniform absorption of energy across<br />
the front of each vehicle. McHcnry (2) developed this<br />
approach and classificd the car population into six<br />
Broups by whcclbase size, each group bcing represented<br />
by a singlc set of energy absorption parameters. In<br />
Europe the EES method (3) has been dcvcloped along
lSth lntematlonal Technlcal <strong>Conf</strong>erence on Expertmentat Satety Vehlclee<br />
similar lines. More complex representations, which allow<br />
for the variation in energy absorption across the width of<br />
thc front of the car and between the upper and lower<br />
parts of the front structure have been made for individual<br />
car type$ (4). Prasad (5) has shown, when the energy<br />
absorption characteristics of individual car types derived<br />
from barrier tests are used to estimate collision speeds,<br />
that the accuracy of estimation is improved.<br />
However in many cases the crush characteristics of the<br />
particular cars involved in a collision are not available to<br />
the accident investigator. In this paper it is shown that<br />
the root(2 x Specific Energy Absorption) or Equivalent<br />
Barrier Impact Speed (EBS) characteristics of the car<br />
population in frontal impacts can be described by a<br />
single equation which can be used to estimate collision<br />
speeds.<br />
Frontal Crush Characteristics of Cars<br />
The crushing force-deformation behaviour of cars is<br />
complex. The initial forces are frequently low, a large<br />
force pulse occurs when the deformation reaches the<br />
engine and the engine is decelerated while the general<br />
level of crushing forces incrcasc as intcraction with the<br />
occupant compilrtment takes place. Emori (6) indicated<br />
in 1968 that the deformation of car fronts could be<br />
approximated by a linearly increasing force characteristic.<br />
Lim (7) in 1972 showed that a paflicular car model<br />
could be represented as having a uniform crushing force<br />
independent of deformation. In CRASH (2) and related<br />
procedures (5) the vehicle structure is represented by the<br />
linearly increasing force model. Prasad (8) has shown<br />
that the energy absorption properties of cars can be<br />
equally well represented by constant force and linearly<br />
increasing force models. Strother (9) and Woolley (10)<br />
have shown that the linear force-deformation assumption<br />
used in CRASH is not valid for all car types particularly<br />
at high collision speeds when force saturation can occur.<br />
In detailed parametric studies of vehicle crashworthiness<br />
Sakuri et al (11) showed that the crushing<br />
force-deformation relationship could be represented by<br />
two regions of constant forcc, an initial low force level<br />
and the second high force area which starts when the<br />
crush deformation reaches the engine.<br />
In the context of collision speed estimation the<br />
predominant interest is in a method which can be used to<br />
rcliably estimate thc cncrgy absorbcd by the colliding<br />
vehicles over the full range of possible collision speeds.<br />
Fonda (12) has suggested that nonlinear force<br />
deformation models give an improved match with the<br />
barrier te$t data.<br />
Normalised Ileformation Model of Frontal<br />
Crush<br />
The energy absorbed in crushing an idealised tubular<br />
structure equals crumpling force times cru$h depth. The<br />
crumpling force is stress times area while vehicle mass<br />
is density by arca by length. Manipulation shows that<br />
(EtMk) * V2l2 = (olp).(dlL)<br />
Equation I shows that the energy of approach, E, of a<br />
vehiclc divided by the mass of the vehicle structure, Mk,<br />
referred to fls the Specific Energy Absorption of the<br />
vehicle, is related to the normalised crush depth (d/L)<br />
and the stress/density ratio (o/p). This relation was<br />
originally proposed by Pugsley (13). This relationship<br />
can also be expressed in terms of the root (2 x Specific<br />
Energy Absorption). This is also called the Equivalent<br />
Barrier Impact Speed (EBS). Taking into account the<br />
more complex crushing behaviour of real cars and to<br />
allow for saturation effects at high speed the relation<br />
(L9lMk)'n = 88.$ = Const+f(olil'@lL)^<br />
is used. Wood (14) has shown that such a equation can<br />
bc used to describc the spccific energy absorption<br />
properties of individual car types for barricr impact<br />
speeds up to 66 mph.<br />
Overall Car Population<br />
Schmidt (15) shows that the kerb weight of cars is<br />
proportional to the wheelbase to the third power. This<br />
infers that the average density of unladen cars is<br />
independent of car size. Danckert (16) shows that the<br />
mean crushing force in 30 mph barrier impacts varies in<br />
proportion to the 2/3 power of kerb mass. This indicates<br />
that the mcan crushing stress of the car population is<br />
indcpcndent of car size. These factors suggest that the<br />
Specific Energy Absorption characteristics of the car<br />
population can be represented by a single equation.<br />
Figure I shows root(z x E/Mk) data for 67 car types<br />
and 205 barrier tests (I4) plotted against normalised<br />
crush depth (d/L) for cars produced between the mid<br />
1950's and the mid 1980's. The figure demonstrates the<br />
nonlinear nature of the relationship. Wood (14) has<br />
shown that equation 2 can be used with exponent, n =213<br />
to model the Specific Energy Absorption behaviour of<br />
the car population. Moore (17) has also shown that<br />
o o a . o 4 s s { o l a * *<br />
N. ZoE<br />
HORM^LI6EP<br />
ctutH REq<br />
(d/L)<br />
Figure 1. Root Speclflc Energy Abeorptlon Versus<br />
Normelized Crush Depth (d/L)<br />
(l)<br />
Q)
impact speed is related to permanent crush to the 2R<br />
power. Regression analysis of the data shown in Figure<br />
I yields the following relationships,<br />
1. 122 Barrier Tests of 26 Car Types from 1975 to 19E6.<br />
(?ElMkJtnmplr = 4.60+l lg,l(d/L)?n<br />
(3)<br />
Coef. of Determination = 0.854, Std. Dev. = 3.7lmph.<br />
2. 163 Barrier Tests of 59 Car Types from lg70 to 1986.<br />
(2ElMk\t4npi - 5.16+11 g.z4(d/L)w (4)<br />
Coef. of Determination = 0.756, Std. Dev. = 4.60mph.<br />
3. 183 Barrier Tests of 66 Car Types from Mid 1950's<br />
to 1986.<br />
(2BlMk\tnmpft.5.05 +119.2(dlL)n (5)<br />
Coef. of Determination = 0.760, Std. Dev. = 4.50mph.<br />
The regression is shown in Figure l.76Vo of the variance<br />
is accounted for by the regression. The remaining<br />
24Vo of the variance not accounted for by the equation is<br />
due to the variation between the characteristics of<br />
individual car types and to the variation in the crush<br />
behaviour of individual cars within any given ciu type.<br />
Application to Frontal Collision Speed<br />
Estimation<br />
Equations 3 to 5 can be used to estimste, from the<br />
permanent crush damage of the cars, the cncrgy of<br />
approach of the vehicles for collisions where in the<br />
course of the collision relative motion between thc<br />
vehicles ceases in the area of mutual contact. The<br />
equations do not account for restitution effects. The<br />
specific energy absorbed by each vehicle is obtained by<br />
calculating the mean valuc of the normalised crush<br />
depth, (d/L) across the full width of the front of each<br />
vehicle, refer Figure 2, and substituting into equation 3,<br />
4or5.<br />
t_<br />
fti;ll,liI^!<br />
Flgure 2. Typlcal Damage Profile<br />
Staged impact tests by Ueyuma et al (18) have<br />
confirmed that the preimpact orientation and overlap of<br />
the vehicles can be rcconshucted by matching the<br />
detailed damage profiles obtained for the collision<br />
vehicles. When the relative orientation of the vehicles is<br />
, : j Sectlon 3: Technlcal Sessions<br />
known, then, for frontat impacts, it is unnecessary to<br />
estimate the direction of the crushing lorccs applied to<br />
each vehicle as the impact equations can be directly<br />
solved from thc relative orientation information, for<br />
examplc refer to Limpert (19). This allows the Collision<br />
Closing Speed (CCS) of the vehicles towards each other<br />
and the magnitude of Delta V of each vehicle (for e = O)<br />
to be calculated.<br />
Missing Vehicle<br />
Often only one of the two cars involved in a collision<br />
is available for measurement. In the collision both<br />
vehicles would have experienced equal and opposite<br />
momentum impulses from the collision process. As the<br />
estimation for crush energy of each vehicle is 0.5 x Mk<br />
x (EBS)2 the magnitude of the impulse can be estimated<br />
as being Mkl,2 x EBS1,2. This yiclds the total crush<br />
energy equation,<br />
Et = EI'll+MkIlMkZl<br />
(6)<br />
where El is the estimated crush energy of the mea.rured<br />
car and Mk1, MkZ arc the kerb masses of the measured<br />
and missing cars respectively.<br />
Comparison with Staged Frontal Collisions<br />
Prasad (4) used data from nine stagcd frontal collisions,<br />
five full width and four with typically 45To<br />
overlap to evuluate the effectiveness of both CRASH 3<br />
and of his reformulation based on the characterisation of<br />
the energy absorption properties of individual car types.<br />
Five different car types were used in these tcsts. No<br />
barrier test data for these five car types were used in the<br />
derivation of equations 3 to 5.<br />
In three of the staged 45% ovcrlap tests only the crush<br />
measurements in the contact zone between the two<br />
vehicles were rcported. Tumbas and Smith (20) have<br />
shown that it is necessary to include measurement of the<br />
induced damage when calculating the absorbed cnergy.<br />
Examination of real world frontal crashes shows that the<br />
induced deformation o[ thc fronts of cars is generally<br />
triangular in nature and that the non contacted portion of<br />
the front bumper and its associated front wing act in a<br />
manner similar to two pinjointed members. Baumann<br />
(21) and Hight (22) confirm this deformation pattern.<br />
This allows the induced damage for the thrcc staged tesl$<br />
to be estimated, refer Figurc 3.<br />
| '*"*r...on *<br />
I coRHER OF 6WFEI<br />
w'rH ffirq'H{ rHr<br />
I<br />
I ewe'-s1 , ,<br />
121--ri_\ \ /<br />
il:rj|V/>^<br />
'{I{rUl,!b[- | I<br />
/ \ -<br />
qEfr<br />
ffiAgT<br />
IHFUGEE<br />
ilM^Et SffiE<br />
Flgure 3. Induced Damaged Correctlon<br />
/<br />
.q<br />
1
13th lntemetlonel Technlcal Conterence on Experlmantat Safety Vehlcles<br />
Table I details the difference between predicted and<br />
actual Delta Vs as a percentage of the predicted value of<br />
Delta V for each car in the nine staged tests when using<br />
1. Equation 3 of General Model<br />
2. hasad's Algorithm (4)<br />
3. CRASH 3<br />
4. Missing Vehicle Estimator with Equation 3 of<br />
General Model.<br />
Tabh 1. Comparison of Percentags Dilference betw€sn<br />
Prodictsd and Actual Delta V's in Nlne Staged Car to Gar<br />
Frontal lmpects uslng Verious Prediction Algorithms<br />
AlgoriLhn<br />
VehicleB<br />
Hdnda'84 Accord 2.65t 6.33+<br />
Chev'84 Celebrity 3,57t 7,45t<br />
Renault'83 Fuego 2,8{+ 5.65t<br />
Ch€v'83 Celebrity -1.57* 1,24*<br />
Honda'84 Accord -5,69+ -3.33*<br />
AIl{c'82 concord -5.50* -3,61*<br />
Dodge '83 omi<br />
A.l,lc '82 concord<br />
Pra8ad({) cRAsH 3 General },!iEEing Vehicle<br />
Mode I<br />
0,34* -18,33*<br />
-0.58t -2.39t<br />
Dods€'83 Out 3.5?t -3.00t<br />
Dodge'83 Omni 3,4?+ -3,14t<br />
Honda '84 Accord 6.118 -6.55t<br />
Honda'84 Accord 0,00+ -11.58t<br />
Renault'83 Fuego 3.90t -5.24S<br />
Renault'83 Fuego -3.33* -11.85t<br />
Honda'84 Accord 9.73t 5.40t<br />
Renault'83 Fuegs 10.17S 6.13t<br />
Dodqe'83 omi 6.13$ 0.33t<br />
chev'83 celebrity 7,11+ 2,?6+<br />
6.33t .40+ / 13.33+<br />
?,33r 1.33+ / 1{.39r<br />
5.92+ -6. 13* / 17.98t<br />
1.24r -10.20r / 1?.90r<br />
-r,{7t 1.53r / -5.73t<br />
-1.?9 1.73r / -s.s4*<br />
1.40t<br />
0.44t<br />
7.69*,/ -8.?0r<br />
6. 65t / -9.08+<br />
-6.0?$<br />
5.99r<br />
'1<br />
.93+ /<br />
t,I4+ /<br />
4.17t<br />
0.'t't*<br />
-4.25t -4.22* / *4.29+<br />
-9.96r -9.93r /-10.06*<br />
-9.41t -9,17S /-10.28r<br />
-15.76t -15.56+ /-15.96t<br />
15.87t 28.90* /-10.70+<br />
13.59+ 2?,40r /-13.68*<br />
-0.83$ -15.77t / 15.30+<br />
0.6?* -14,{gr / 77.03*<br />
Statistical analyses of the results are shown in Table 2.<br />
Trble 2. $tatlrtlcal $ummrry ol Comparieon bstween<br />
Predicted and Actual Delta V's<br />
Algdrlthfr<br />
Iteh<br />
No of DaEa<br />
Mean Dlfference t<br />
Standard Devlatlon t<br />
Mean AbEolute<br />
Difference t<br />
R.M.S. Dlfference t<br />
Prasad's<br />
Algoritttr<br />
ls<br />
2.39<br />
4.63<br />
4.24<br />
5.10<br />
CRASH 3 General<br />
Mod€l<br />
-1<br />
18<br />
ql<br />
5 .78<br />
? .95<br />
5 .99<br />
7 .42<br />
Mlssing<br />
V€hicle<br />
11 .91<br />
9.85<br />
Comparison shows that the standard deviation obtained<br />
when using Prasad's algorithm is 4.63Vo while it is<br />
7.95% when using the general model, 7.l4Vo using<br />
CRASH 3 and ll.9lVo when using the Missing Vehicle<br />
estimator with the General Model- Variance Ratio tests<br />
show no significant difference between the General<br />
Model outlined in this paper and CRASH 3. Prasad's<br />
algorithm (4) is significantly better than both at the 5<br />
level but not at the l% level. The Missing Vehicle<br />
estimator is significantly worse than the General Model<br />
and CRASH 3 at the STolevel but not at the l7o level.<br />
198<br />
The data $hows that the<br />
prediction of Delta V are,<br />
Prasad's Algorithm<br />
CRASH 3<br />
General Model<br />
Missing Vehicle + General Model<br />
95Vo confidence limits for<br />
tl09o<br />
tlSVo<br />
tlTVo<br />
l74Vo<br />
This analysis shows that the Specific Energy<br />
Absorption properties of the car population in frontal<br />
collisions can be represented by a single equation and<br />
that when applied to prcdict the Dclta V's in nine staged<br />
collisions accuracies similar to CRASH 3 are obtaincd.<br />
When the energy absorption properties of the individual<br />
car types are known a significant improvement in Delta<br />
V prediction is obtained. However this data is not<br />
available for many, particularly European, car modcls.<br />
When only one vehicle is available for pcrmanent crush<br />
measurement the Missin Vehicle estimator tlerived here<br />
can be used to calculate the total crush energy but gives<br />
a coarser prediction of Delta V than when both $ets of<br />
crush measurements are available.<br />
References<br />
1. Campbell, K L "Energy basis for collision severity"<br />
SAE Paper 740565,1974.<br />
McHenry, R R "A comparison of results obtained<br />
with different analytical techniques for<br />
reconstruction of highway accidents" SAE Paper<br />
750893, 1975.<br />
Zeidler, F et al "Accident research and accident<br />
reconstruction by the EES accident reconstruction<br />
method" SAE Paper 850256, 1985.<br />
Nilsson-Ehle, A et al "Evaluation of a method for<br />
determining the velocity change in traffic accidents"<br />
SAE Paper 826081, 1982.<br />
Prasad, A K<br />
"CRASH<br />
3 damage algorithm<br />
reformulation for front and rear collisions" SAE<br />
Papcr 900098, 1990.<br />
Emori, R I "Analytical approach to automohile<br />
collisions" SAE Paper 680016, 1968.<br />
Lim, G G "Crash data analysis" SAE Paper 720496,<br />
t972.<br />
8. Prasad, A K "Energy dissipated in vehicle crush-a<br />
study using the repeated test technique" SAE Paper<br />
900412<br />
9. Strother, C E et al '*Crash Energy in accident<br />
reconstruction" SAE Paper 860371, 1986.<br />
10. Woolley, R L et al "Inaccuracies<br />
in the CRASH 3<br />
program" SAE Paper 850255, 1985.<br />
ll. Sakuri, T et al "On the safety body structure of<br />
finite element method analysis" Proc. 12th. E.S.V.<br />
<strong>Conf</strong>erence, 1989, p. 327- 333.<br />
12. Fonda, A G '*Crush n<br />
3.<br />
4.<br />
f.<br />
6.<br />
7.<br />
energy formulations and<br />
single-event reconstruction" SAE Paper 900099,<br />
1990.
13. Pugsley, A 'Tte crumpling of tubular structures<br />
under impact conditions" Proc. of Symposium on the<br />
use of aluminium in railway rolling stock, Instn. of<br />
Locomotive Engrs., London 1960, p. 33-41.<br />
14. Wood, D P et al "Frontal collision speeds from<br />
damage-an empirical approach" Proc. of the<br />
Canadian M.R.S.<strong>Conf</strong> .7, p. 264-274.<br />
15. Schmidt, R "Realistic compatibility concepts and<br />
associated testing" 6th. E.S.V. 1976, p. 234 -247.<br />
16. Danckert, H<br />
"Development<br />
of crash energy<br />
management solutions" SAE Paper 760793, 1976.<br />
17. Moore, D F "Minimization of occupant injury by<br />
optimum front end design" SAE Paper 700416,<br />
1970.<br />
st-w.2g<br />
Special Product/Person CVS-ATB 3-D Simulations<br />
Donald Friedman<br />
Donald Friedman Liability Research Group<br />
<strong>Int</strong>roduction<br />
The versatility of the CVS-ATB 3-D simulation<br />
program is demonstrated by its use in varied product<br />
liability research. The power of this protocol is the<br />
scientific interpolation of the facts or witness marks and<br />
the time history of dctailcd accident events which make<br />
it far more accurate and reliable than popular illustrative<br />
animations. This paper describes the validation and<br />
qualification of hypotheses on injury accidents involvin g:<br />
I. boat propeller/swimmcrs;<br />
2. vision scnsitivity;<br />
3. football helmets;<br />
4. rollovers;<br />
5. ejection;<br />
6. pedestrian impact trajectory; and,<br />
7. asymmetrical seat back failure.<br />
A brief description of a sample case history of each<br />
accident type is given, followed by thu procedure used to<br />
reconstruct the accident/inj ury.<br />
Case History Analyses<br />
B o at P rop e Il e r I Swi mme r s<br />
In the U.S., outboard motor propellers frequently<br />
injure thousands of swimmers at very low boat speeds.<br />
A long standing invention is the caged propeller whose<br />
edges are precluded from contacting swimmers. A recent<br />
case involved a young man whose leg was sliced to the<br />
bone from hip to ankle. To reconstruct the accident, a<br />
stuntman was overrun with a caged propeller without<br />
injury. Understandably, there were no volunteers for the<br />
open propeller, although thc regularity of the victim's<br />
cuts needed no physical dcmonstration as to what<br />
happened.<br />
. Sectlon 3: TechnlcalSesslons<br />
18. Ueyuma, M et ut "Drrrrtination of collision<br />
configurations from vehicle deformation patterns"<br />
SAE Paper 910127, 1991.<br />
19. Limpert, R "Motor vehicle accident reconstruction<br />
and cause analysis" Publ. Michie 1989.<br />
20. Tumbas, N S et al "Mcasuremcnt protocol for<br />
quantifying vehicle damage from an energy basis<br />
point of view" SAE Paper 880072, 1988.<br />
21. Baumann, K H et al "Frontal offset crash testing for<br />
approximately 15 years: results, experiences and<br />
consequences" SAE Paper 900413, 1990.<br />
22. Hight P V et al "Barrier equivalent velocity, delta V<br />
and CRASH 3 stiffness in automobile collisions"<br />
SAE Paper 850437, 1985.<br />
We created a rotating propeller whose size and speed<br />
could be set on a shaft, attached to a boat, and we then<br />
floated a Hybrid III dummy under the boat so that it<br />
interacted with thc bladcs of the propeller producing the<br />
injury as shown in Figure I at 0, 150 and 300<br />
milliseconds.<br />
Figure 1. Rotatlng Englne Propeller on Pontoon Boat<br />
Contrecting Hybrid lll Swimmer at I mph, Viewed from<br />
the Hear<br />
Thcn we caged the propcller and repeated the event.<br />
The differences in the kind and levcl of injury wcre<br />
obvious and identified by using GM HYBRID III Injury<br />
Measure Criteria. The following figure 2 illustrates the<br />
same scene intervals with a caged propeller from a<br />
camera position below the swimmer.
13th lnternatlonal Technlcal <strong>Conf</strong>erence on Experlmental Safety Vehlcles<br />
mffim<br />
ffi<br />
ffi<br />
m<br />
Figure 2. Caged Rotating Engine Propeller on Pontoon<br />
Boat Contrecting Hybrid lll Swimmer at I mph, Viewed<br />
lrom Below<br />
Vision Sensitivity<br />
A small child on a plastic "Big Wheel" tricycle rode<br />
a long driveway and into the road immediately behind a<br />
parked car. Low hedges, a tree and the parked car<br />
obscured the child from the driver of a Cadillac procccding<br />
down the residcntial street at a moderate rate of<br />
speed. The driver claimed he couldn't see thc child until<br />
it was too late to stop. The child was brain damaged by<br />
a strike from the right front bumper.<br />
Thc manufacturer of the tricycle offered a visibility<br />
pennant on a 60" wand as an option. If attached, it would<br />
have substantifllly altered the conspicuity of the moving<br />
tricycle and child to the driver.<br />
The scene was recreated with the parked car, hedges<br />
and driveway. A parametric study was donc, based on<br />
the uncertainty of the speed of the car and the tricyclc.<br />
Cameras observing the scene were located at the site of<br />
the stationary witness and the moving drivcr who were<br />
asked to judge which speeds best suited their recollection.<br />
Then, thc tricycle was fitted with a fluttering<br />
pennant which made the tricycle motion clearly visible<br />
to the driver several seconds earlier than in the accident.<br />
Figure 3 and 4 show the scene in time sequence from the<br />
viewpoint of the driver.<br />
Football Helmets<br />
Several cases involving football player interaction<br />
during a game have resulted in quadriplegic neck injuries<br />
and have been modeled. The actual play scenes have<br />
always been documcnted in real time with game film<br />
cameras. In conjunction with player and witness<br />
testimony and the $pecific characteristics of the injury,<br />
200<br />
Flgure 3. Child on Tricycle from Gamera et Driver's Eye<br />
Point Emerged from Hedges but Stlll Behind Tree and<br />
Parked Cer to lmpact<br />
"o;-:o.<br />
E<br />
,{l-;.}<br />
\cl;_b.f<br />
E-- L+<br />
{{( i. i')<br />
1\.-\--1---r./<br />
q+;:=;:<br />
Lb,<br />
_r;+:*<br />
4 00 ons<br />
|<br />
t t l<br />
ll I runrF<br />
- l l l ' - -<br />
F-r--r- I I I<br />
L.t_J<br />
Figure 4. Child on Tricycle with Flutterlng Pennant, from<br />
Camera at Driver'e Eye Point Emerged from Hedges but<br />
Still Behlnd Tree and Parked Car on lmpacl<br />
\;<br />
\*<br />
\<br />
\<br />
\*<br />
\<br />
.",;++<br />
I<br />
.r-- l1<br />
ll -<br />
L-_t<br />
Figure 5. Motion end <strong>Int</strong>erection of Opposing Football<br />
Players from Game Camera Position Duplicating Injury<br />
Action<br />
this has been sufficient to recreate the kinematic<br />
interaction in detail as shown in figure 5.<br />
By placing computer $cene cameras at the sites of the<br />
actual gamc camcra as well as at the location of<br />
witnesses, discrepancies with details could bc rcsolved<br />
in individual recollections relating to the orientation of<br />
the players relative to the field markings and each other,<br />
which assisted in quantifying the contact impact<br />
orientation and velocity.<br />
|<br />
-<br />
|
80 Er<br />
Flgurc 6. llbtbn and <strong>Int</strong>ersction ol Opposlng Football<br />
Flayers from Far $lde Witness Camera Poshlon<br />
Duplicating Inlury Action<br />
In particular, this protocol moved the demonstration<br />
and performance of helmets from considering the<br />
effectiveness of a head/lrelmet into wall impact, to<br />
consideration of the mass effects (such as head to thigh)<br />
and to inertial and compliance effects (such as head to<br />
edge of abdominal torso).<br />
Flgure 7. ltlotlon and <strong>Int</strong>ersction of Opposlng Football<br />
Players from a Clos+Up Camera<br />
These considerations led to a more refined understanding<br />
of the effectiveness of the top of the hcad/<br />
Sectlon 3: Technlcal Sessions<br />
helmet force/deflection characteristics. That in turn led<br />
to suggestcd modifications and improvements limiting<br />
the risk of quadriplegia.<br />
Rollovers Involving Roof Crush Injuries<br />
A variety of rollover accidents have been simulated<br />
from the initiation of yaw rotation to the lateral trip<br />
point and with the help of surface witness marks the<br />
touchdown points, orientations and time history of<br />
occupant events.<br />
From the technical perspeclive, the SMAC program is<br />
generally used to relate vehicle planar motion and to<br />
establish the take off conditions at roll initiation and<br />
CVS simulation. The orientation of the vehicle in six<br />
displacement coordinates at several witness mark locations<br />
are estimated, and a spline fit is developed to<br />
connect the points; thc spline fit is calcultted not only in<br />
displacement, but velocity and acceleration as wcll.<br />
Graphical plots of the motions arc rcviewed for<br />
reasonableness, comparison to test data, and empirical<br />
rules. The curves are reshaped and regencrated (iterated)<br />
to remove obviously impractical inflection points and<br />
excessive rates. as well as lo enhance short term contact<br />
accelerations and/or delbrmations.<br />
The process is not precise, but far morc accurate and<br />
explicit than a verbal description and playing with model<br />
cars. And it is subject to validation by the occupant<br />
kinematics in rclation to interior witness marks. Because<br />
having established thc Fajectory, we place the occupants<br />
in the compartment and observe their motion, interior<br />
contacts and the resulting forces on various body parts.<br />
Usually the major injuries are immediately evident or the<br />
adjustments are obvious.<br />
Two technical observations are important.<br />
l. The circumstances of an accidcnt are so complicated,<br />
the number of variables so large, and the<br />
ability to know the unknowable so limited, that a<br />
adversary litigant almost always attempts to discrcdit<br />
the validity of the cffort. One must agrcc<br />
with the limitations of precision, but therc is only<br />
one recognized limitation to the claim of accuracy<br />
and that is the demonstration of an alternate<br />
reasonable interpolation of thc factual evidence.<br />
Each time such an alternate sccnario has been<br />
demonstrated (with accompanying photographic or<br />
instrumcntation output), the ability to cornpare<br />
results makes thc truth clear even to the lawyers,<br />
and the case settles (so far, always in favor of the<br />
victim). What this means is that the circumstances<br />
are so complicated and the number of pieccs of<br />
factual (physical) evidencc so great that there are<br />
- no two ways to quantitatively describc it without<br />
making judgmental errors obvious.<br />
2. There are times when the limitations of the model<br />
can cloud the issucs. This is usually the case when<br />
vehicle component intrusion occurs during an<br />
occupant contact. Because CVS cannot normally<br />
201
13th lnternatlonel Technlcal <strong>Conf</strong>erence on Experlmentel Salety Vehlcles<br />
o sEc 5 scc<br />
4##<br />
3.0 sec 3 .5 ssc<br />
: -++<br />
?.5 sec<br />
Flgure 8. Vehlcle Trafec,tory ilotlon from Loaving the<br />
Road and Durlng Rollover from Stationary Camera in<br />
Front of Rest Pocltlon<br />
move surfaces as a function of time during an<br />
event, we usually determine (and initially set) the<br />
positions of those surfaces relative to the point in<br />
time at which the occupant gets there.<br />
However, if the impact is strongly dependent on<br />
the surface motion, we have developed a way to<br />
give that surface its own displacement pulse which<br />
parallels the vehicle until dcformation takes place.<br />
This is usually important and therefore used in roof<br />
crush cases.<br />
The illustration of Figure 9 is a vehicle with<br />
ample head room which has gone out of control,<br />
rolled one and a half times, ending up side down<br />
on the roof with the belted 50th percentile male a<br />
quadriplegic from roof collapse to the window sill<br />
during the 200 ms at final touchdown.<br />
Rollover with Ejection<br />
The rollover procedure previously described, and<br />
providing ejection portals, usually provides the answers<br />
directly. I am reminded of a case described in SAE<br />
890382 ("Live Subject Safety Research") in which the<br />
time of ejection determined the time of belt release, and<br />
another case in which a small four year old unrestrained<br />
boy came out a rear side window after a left frontal<br />
offset impact induced a violent counterclockwise yaw<br />
prior to the initiation of roll.<br />
But the case study here is an ejection during a roll. A<br />
young unrestrained woman driving friends on a dirt and<br />
gravel mountain road loses control and goes off the road.<br />
She goes out the open window as the roll is in process.<br />
202<br />
L50 ns<br />
Figure 0. Holloyer Hool Collapse on a Belted Occupant<br />
wlth Extensive Headroom from an Onboard Rear View<br />
Camera<br />
In considering countermeasures, the pos$ibility of<br />
reducirtg the size of the side window by upper fixed<br />
laminatcd glazing would have significantly strcngthened<br />
the roof and prevented the ejection. This was demonstrated<br />
with a window (outlook) input modification and<br />
rerun.<br />
..!'-,<br />
Flgure 10. Rollover EJection ol an Unbelted Occupant<br />
from an Onboard Side View Camera<br />
N i ghttime Tr uc kl P edes trian I mpac t<br />
An intcresting analysis was required in the case of a<br />
pedestrian struck by a large semi-tractor truck at night<br />
on a rural road. The questions to be resolved were
concerned with where the pedesfian was when he was<br />
struck, where on the vehicle was he struck. what was his<br />
trajectory to his place of rest on the shoulder, and could<br />
the driver have been taking evasive action at the time of<br />
contact.<br />
The truck's right-front corner wfls particularly uniform<br />
in its radius of curvature, and its deformation, as a result<br />
of the impact, war clearly indicated, The driver's<br />
account establi$hed the impact point to be less than 100<br />
feet from the pedestrian's point of rest due to his recognition<br />
of landmarks. This established the truck's velocity<br />
as more like 40 mph, as he claimed, than 50 claimed by<br />
the plaintiff witnesses.<br />
A hybrid three dummy was placed standing erect at<br />
the right front corner of the truck moving at 40 mph, and<br />
the series of 50 millisecond impacts were devetoped to<br />
determine the effective body part injuries. The pedestrian<br />
had received severe brain damaging head impact, several<br />
fractured ribs on the left side, bruised left hip and thigh<br />
tissue with no other significant injuries. The injury<br />
measure$ identified for the Hybrid III dummy allowed us<br />
to move the dummy in one inch increments relative to<br />
the truck edge, right and left of the body centerline.<br />
Using this technique, we were ablc to identify the<br />
probable strike position within one inch and about 20<br />
degrees of mid-sagittal plane rotation.<br />
0mg<br />
t - X t t - l t r -<br />
I lhlt__Al [_r<br />
HIHIH<br />
Flgure 11. Frdestrian lmpact on the Right Front Corner<br />
of s Tractor/Traller to Locate lmpact Po$itlon lrom<br />
Delormstlon rnd Inlury<br />
Having selected the strike position, we allowed the run<br />
to develop for three seconds during which time the<br />
pedestrian came to rest on the surface about eight feet to<br />
the right of the truck, about 70 feet from the strike<br />
position and oriented as the witnesses had found him.<br />
Once having created the scene, it was possible to view<br />
it from cameras located on the truck, on the ground,<br />
overhead, etc. The tabular positions of each of the body<br />
parts also allowed the motion of thc pcdestrian after<br />
impact to be color-coded and overlaid wirh clothing and<br />
more realistic and recognizable features than the wire<br />
frame output, the technical mode of analysis, without<br />
losing science in favor of illustration.<br />
Other features consisted of locating the camera at the<br />
dfiver's viewpoint prior to impact, and estimating, on the<br />
basis of conspicuity, the driver's reaction time and<br />
vehicle response characteristics.<br />
t '"" r'l<br />
LtlLl<br />
Sectlon 3: Technlcal $esslons<br />
1,5 B6C 2.0 Bec 2,5 rec<br />
Flgure 12. Pedestrlan lmpact on the Right Front Corner<br />
of e Tractor/Traller and Propelled Forward and to the<br />
Shoulder ol the Rosd from a Rear blounted Vehicle<br />
Gamera<br />
Asymme tri c al S e at-B ack F ai I ure<br />
This case is a relatively low speed rear impact in<br />
which the seat back failed af the hinge point on the left,<br />
but not on the right. The consequence was to cause the<br />
driver to displacc aft with a high angular rotalion rate<br />
around his spine producing a torsional failure in his<br />
lumbar spine. This was contpared with the lack of injury<br />
which would have resultcd from the same circumstances<br />
had the left hinge not failed.<br />
Figure 13. Asymmetrlcal S€at Back Failure Resulting in<br />
Lumbar Spine Torsional Inlury from Left Hear Package<br />
Shelf Camera<br />
Conclusions<br />
The facility with which accident injury simulations<br />
can be conducted and itcrated using the Hybrid III<br />
J<br />
203
13th tntemettonel Techntcal <strong>Conf</strong>erence on Experlmental Satety Vehlcles<br />
dummy (or a re-sized Hybrid III based on victim characteristics)<br />
is a powerful tool in relative terms and more<br />
effective than physical testing.<br />
Establishing the interactive force/defl ection properties<br />
presents a problem in absolute terms which can be<br />
resolved by duplicating a physical tesq but the reality of<br />
litigation is associatcd with the correction of defects, a<br />
relative parameter. As such, the CVS model can be considered<br />
an ideal diagnostic tool for low cost analysis,<br />
validation and qualification of expert opinions in much<br />
the same way that it is used in adjusting designs to<br />
optimize performance in the original design process'<br />
The CVS model forms the basis for a tcchnical<br />
presentation of data based on the laws of physics' It is<br />
not only illustrative, but it has a potential graphical<br />
impact on the lay public.<br />
References<br />
l. "tive Subject Safety Research;" D. Friedman, S.<br />
Forrest, F. Gott, G. D. Dyne, SAE 890382. SAE<br />
32nd STAPP Car Crash <strong>Conf</strong>erence in Atlanta GA,<br />
1989.<br />
"Rcconstruction<br />
2.<br />
of Frontal Accidents Using the CVS<br />
3-D Model," K. Diggs, SAE 840869.<br />
*'Prediction<br />
3.<br />
of an Occupilnt's Motion During<br />
Rollover Crashes," SAE 861876, L. Obergefell' I.<br />
Kaleps, A. Johnson.<br />
4.<br />
"An<br />
Improved Three Dimensional Computer<br />
Simulation of Vehicle Crash Victims," Vols. I-IV. J.<br />
T. Fleck, Calspan Corp., April 1975; PB-241-692,<br />
DOT-HS-801-50?.<br />
"Development<br />
5.<br />
of an <strong>Int</strong>eractive Computer Program<br />
to Produce Body Description Dara, GEBOD,* L.<br />
Baughman, Air Force Aerospace Mcdical Rcsearch<br />
Laboratory, July 1983; AFAMRL'TR-83-058'<br />
6.<br />
"Recent Improvements in Occupant Crash<br />
Simulation Capabilities in thc CVS/ATB Model,"<br />
SAE 880655, K. Diggs, NHTSA, March 1988.<br />
"Improvements<br />
7.<br />
in the Simulation of Unrestrained<br />
Passengers in Frontal Crashes Using Vehicle Test<br />
Dara," SAE 860605, K. Diggs, 1986.
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