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A two dimensional dynamic model, which provides a full description of a vehicle motion based on sensory input, is presented. The model has three sensory inputs: the velocity of a fifth wheel; the orientation of the fifth wheel with respect to the vehicle; and the yaw rate of the vehicle. Based on these inputs, the model determines the position, velocity, acceleration and the yaw angle of the vehicle. The results of experiment with an instrumented vehicle, which were designed to verify the validity and accuracy of the model, are reported.

The critical speed model is a tool used by accident reconstructionists to determine vehicle speeds. One assumption implicit in the model is that when in a critical speed yaw, the vehicle's center of mass travels in a circular arc. The validity of this assumption was investigated by comparing the results obtained by manually measuring the tire marks, assuming them parallel to the center of mass path, and fitting a polynomial. The results indicate that the assumption of a circular path is reasonably accurate.

When performing calculations pertaining to the analysis of motor vehicle accidents, investigators must often select appropriate values for a number of parameters. The uncertainty of the final answers is a function of the uncertainty of each parameter involved in the calculation. This paper presents the results of recent tests conducted to obtain sample distributions of some common parameters, including measurements made with tapes, measurements made with roller-wheels, skidmark measurements, yawmark measurements, estimation of crush damage from photographs, and drag factors, that can be used to evaluate the uncertainty in an accident reconstruction analysis. The paper also reviews the distributions of some pertinent data reported by other researchers.

The most frequently cited papers on driver abilities are somewhat dated. This paper reports on the abilities of a large sample of drivers as they negotiated a closed cone-marked course using modern vehicles. The steering wheel position, brake line pressure, and throttle application were monitored, along with vehicle chassis accelerations. The objective of this paper is to report on the physical inputs utilized by operators, and compare gender-specific and vehicle-specific results. Willingness limits and g-g diagram results are presented.

This paper compares the analytical response of a low speed, in-line, vehicle impact with that of a simulated bumper test involving a rigid striker. Results from a previously validated analysis procedure indicate that a rigid pendulum mass impact test on a vehicle bumper, such as the one currently mandated by the federal government, yields significantly different results from that of a typical two-vehicle impact. This paper then proposes methods by which the existing government tests could be extended to yield additional design and analysis data that could be used to help design lower vehicle compartment loadings.