A Review of Building Evacuation Models - NIST Virtual Library

evacuation time and the number of occupants trapped are provided in the output. Stair and floor
clearing times are also included.
Use of fire data: Fire data can be imported from CFAST 98 .
Import CAD drawings: No. Building data is specified through the node and arc inputs.
Visualization capabilities: No visualization
Validation studies: Several validation studies are available for EXIT89. One study involves
comparing results from a fire drill involving 100 occupants from a 9-story building. Both the
emergency and normal evacuation speeds were used in two different simulations of the building.
An error of 20 % was noted from the emergency run (5.6 min from EXIT89 and 7 min actual
evacuation time), and the normal run overestimated the evacuation time by 43 %.
The second validation study was performed using a 7-story office building in Newcastle-on-
Tyne in the UK. The fire brigade captured this data, and during the fire drill, challenged the
occupants by blocking access to one of the stairways. The fire brigade captured information
from different exits as well as surveyed occupants on their initial location, exit used, and delay
times before beginning evacuation. During the fire drill, the occupants used the most direct
route possible out of the building, sometimes ignoring closer exits and/or climbing stairs to get
there. Fahy used EXIT89 to first send all occupants to the closest exit, and second to use the
user-defined route option to mimic the occupant paths during the drill. The results are found in
Table A.14 below.
Table A.14: EXIT89 validation study results from the 7-story office building
Observed Predicted – Shortest Route Predicted – User Defined
People Last Exit People Last Exit People Last Exit
Exit 1 2 45.9 s 2 35.0 2 35.0
2 6 48.0 6 26.0 6 26.0
3 6 90.0 107 148.0 6 36.0
4 40 105.0 124 153.0 51 104.0
5 0 - 7 72.0 7 103.0
6 23 115.0 27 109.0 26 95.0
7 0 - 0 - - -
8 48 190.0 6 60.0 30 120.0
9 8 90.0 11 54.0 11 54.0
10 248 220.0 91 107.0 242 162.0
Total Exited 381 286.0 381 153.0 381 162.0
The predicted results from the shortest route simulation provided a shorter evacuation and much
different flow split than the actual/observed data. Fahy states that this is due to the unusual use
of exits and the overwhelming use of Exit 10 by the occupants of the building. After running a
user-defined simulation, the flow distributions seemed more reasonable, but the overall
evacuation time of the prediction still provided results of approximately 2 min under the
observed time. Fahy suggests that the reason for this discrepancy is that EXIT89 was not
equipped with pre-movement or delay time capabilities at the time of this validation work.
A-80