Keith Vodden Dr. Douglas Smith - Transports Canada

Ontario Model
5. Tow trucks
Tow truck services are required when either or both the vehicle cannot be driven
safely or no licensed individual is able to drive the vehicle from the collision scene. Data
from Transport Canada’s former Passenger Car Survey (PCS, data used by the study are
from 1984 to 1989) indicate that 89% of the vehicles involved in fatal collisions were
towed and 57% of those involved in injury collisions required the services of a tow truck.
We assume that 40% of vehicles involved in PDO collisions (not included in the survey
coverage) were towed. Thus, the number of vehicles in each type of collision that were
towed is derived by applying these proportions to the total number of vehicles involved in
collisions including those that were not damaged (in keeping with the survey coverage).
As a check on the correct proportion to use, the per cent of vehicles that are demolished
or have severe or moderate damage is 86%, 63% and 46% for fatal, injury and PDO
collisions respectively. The percentages identified from the PCS and by extrapolation
approximate these percentages based on vehicle damage with slightly higher percentages
for fatal collisions and lower percentages as collision severity declines. This is in keeping
with our expectations that more vehicles will be towed for reasons other than vehicle
damage as collision severity increases. Our costing methodology deducts estimated costs
for tow truck services from insurance payments calculated elsewhere. As a result any
error in our estimate of tow truck costs will be countered by an off-setting error in the
value of remaining items paid for through insurance claims.
E. VALUATION OF HUMAN CONSEQUENCES
1. Willingness to Pay (WTP) Estimates
The willingness to pay approach to estimating the value of human consequences is
rooted in the observation that individuals make choices each day that balance risks of
injury and death against monetary considerations. Whether they decide among vehicles
with different safety and price characteristics or among jobs with different work-place
accident and pay characteristics they explicitly or implicitly make trade-offs that must
balance these factors. By extension, society balances the benefits of risk reduction against
the costs to achieve the lower risk when it decides to invest in passing lanes, road divider
barriers, and better curve banking that offer the potential to reduce collisions and
fatalities.
A number of Canadian studies have been able to use rich labour market data
(remuneration and risk variables) to estimate the value of human consequences. The most
recent research results on risks and the value of measures to reduce these risks indicates
that the benefits of reducing these risks are much higher than had previously been
estimated. Most of these earlier studies were unable to correct for known biases in these
data, producing as a result, artificially low values of a life saved and injury avoided.
The most recent Canadian estimates of the value of statistical life (Dr. Morley
Gunderson and Douglas Hyatt in the Canadian Journal of Economics, Volume 34. No. 2,
TNS Canadian Facts, Social and Policy Research 29