He said, She said: Let the evidence speak for itself.


Case Synopsis: A motorcycle and pickup truck were traveling in the same direction on a four-lane roadway.  As the pickup truck was entering an intersection, another vehicle turned in front of it, forcing the pickup operator to brake and/or steer to avoid it. The motorcyclist stated that he was traveling in the right lane alongside the pickup truck when the pickup truck swerved from the left lane to the right lane and contacted him in the intersection.  Conversely, the pickup truck operator claimed that he was in the left lane at all times, braked aggressively without leaving his lane, and never came into contact with the motorcyclist behind him in the left lane.

An independent witness who was stopped at the other side of the intersection testified that he observed the crash, but could not see if the truck swerved or contacted the motorcycle.  Furthermore, he testified that he could see the front wheel of the motorcycle come to a stop and the rear wheel of the motorcycle lift off the pavement as it crashed. 

Expert Analysis: An expert was retained to evaluate the available data to determine, if possible, which story made more sense.  The intersection and vehicles were plotted to-scale and each scenario was evaluated.  The damage to the motorcycle was consistent with the “over-the-bars” type of crash dynamics that can result from over-application of the front brakes on certain motorcycles.  There was no physical evidence to rule out the pickup truck operator’s story.

On the other hand, the point of rest of the motorcycle near the center of the intersection was not consistent with the motorcyclist’s version of events or the laws of physics.  That is, the motorcycle could not have come to rest in the center of the intersection based upon his testimony.  His recollection regarding how the collision occurred and how he was controlling the motorcycle at the time would not result in the motorcycle collision dynamics observed by the independent witness.  Finally, based upon a three-dimensional analysis of the sight lines, it was demonstrated that the independent witness would not have been able to see the motorcycle’s wheels had it been in a location in the right lane alongside the pickup truck.

Case Result:  The physical evidence and available data were consistent with the motorcyclist being behind the pickup and crashing as a result of over-application of the front brakes.  The jury found in favor of the pickup truck operator.

Curtis M. Beloy, PE is an Accident Reconstruction / Motorcycle Safety Expert with DJS Associates and can be reached via email at experts@forensicDJS.com.

Categories: Case Studies


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