Citation

Andreatta D, Guenther DA. Accid. Reconstr. J. 2007; 17(5): 19-22.

Copyright

(Copyright © 2007, Accident Reconstruction Journal)

DOI

unavailable

PMID

unavailable

Abstract

This article reports on research conducted following an accident involving a coal truck running with possibly overinflated tires. The truck was traveling eastbound on a 2-lane, asphalt road when traffic ahead slowed down. The driver of the coal truck applied his brakes leaving a number of skid marks, and the truck jackknifed to the left, crossing the centerline. A westbound passenger car struck the front of the tractor, killing the driver of the car. Claims were made that the coal truck was running on overinflated tires, that evidence of the overinflation was the width of the skid marks, that overinflated tires caused the trailer tires to bounce when the brakes were applied, that this bouncing reduced the trailer's braking efficiency, and that, in turn, this caused the jackknifing. It should be noted that the inflation pressures of the tires were not measured at the time of the accident; one of the key claims was that the pressure could be inferred from the appearance of the skid marks and the wear pattern of the tires, which was generally uniform across the tire. These claims were investigated in 2 ways, by comparing the claims to what is currently known about jackknifing, truck braking, and wheel hop, and by direct testing of an exemplar vehicle. In addition, some tire patch shape and size testing was performed. Conclusions are presented.