Steven M. Schorr, P.E.
Collision Reconstruction Engineering Consultant ::::
A single vehicle collision occurred when a sport utility vehicle [SUV] rolled over, severely injuring the plaintiff, a restrained, right-front seat occupant. The plaintiff’s theory, a crashworthiness argument against the manufacturer, claimed that improper design of the roof resulted in the roof crush that led to the injuries. As a foundation of the crashworthiness analysis, the automotive design engineer required information as to the dynamics of the rollover.
The collision reconstruction engineer’s role in this analysis was to define, if possible, based on the available physical evidence, the speed at which the vehicle rolled, the number of times the vehicle rolled, and the roll rate. The physical evidence utilized in the analysis included the point of rest of the SUV, wheel rim gouges on the roadway, and the damage to the SUV. The wheel rim gouges were utilized to define the contact points between the rolling SUV and the roadway and, in conjunction with the damage to the vehicle, to help define the overall dynamics of the vehicle.
Utilizing the point of rest of the vehicle, the location of the gouge marks, and the pattern of the scratch marks on the SUV, the number of times the vehicle rolled was defined. The average roll rate was quantified based on the distance between the rolls and the speed analysis.
As a side note: when the vehicle was inspected, the dimensions of the vehicle including the roof crush were documented utilizing a high-definition survey [HDS] laser scan. The HDS laser scan provided the engineers with an accurate [to within 3mm] three-dimensional model of the crushed vehicle. These measurements [compared to an undamaged vehicle] were utilized by the crashworthiness engineers in their analysis. The scale models were then utilized for demonstrative evidence.