Collision Between a Tractor/Semi-Trailer
and School Bus
May 31, 2001
Highway Accident Report
Videos are available in wmv format and were presented at the Board meeting on September 4, 2002 in Washington, D.C.
Disclaimer: Simulations presented below used scene surveys,
vehicle and scene testing, vehicle operating characteristics, pictures and witness
statements. The depictions do not represent actual lighting and weather conditions
at the time of the accident.
Vehicle Dynamics: Five different views of the vehicle dynamics were rendered to show various perspectives of the crash. Prior to exiting the Interstate onto the exit ramp, a fully loaded tractor semi-trailer, with braking deficiencies, had descended a 12-mile downgrade. In the simulations, the initial speed of the loaded tractor/semi-trailer at the top of the ramp was about 33 mph. The tractor/semi-trailer's speed increased to about 48 mph on the ramp's steep downgrade as the brakes faded prior to impact and the truck ran past a stop sign. The school bus approached the intersection at about 50 mph.
Video = 723K
This is a chase view of the truck on the ramp as it travels toward the intersection and collides with the school bus in real time.
Video = 545K
This is a chase view of the schoolbus as it approaches the intersection.
Video = 163K
This is an oblique intersection view of the collision.
Video = 706K
This is the truck driver's potential front and left views as the vehicle approaches the intersection, displayed in a split screen format.
Bus Split View
Video = 361K
This is the bus driver's potential front and front middle views as the vehicle approaches the intersection, displayed in a split screen format.
The simulations were produced on an HVE system using EDSMAC4 SIMON and EDGEN programs. All of the programs are trademarks of the Engineering Dynamics Corporation. The movies were produced in Adobe Premiere. The program is a trademark of the Adobe Systems Incorporated.