The study of vehicle collisions is important for evaluating the potential hazards of failure events. This study uses a two-dimensional simulation model to investigate collisions in vehicle following operations. The simulations provide a means for evaluating the effects of operating variables on post-impact vehicle motions. It can be concluded from the simulations described in this paper that small spacing and small lateral offset in vehicle following offer potential benefits in minimizing post-impact deviations from the original paths and rotation from the original orientation. The time it takes for a vehicle to depart from its original lane is shorter for those cases with greater lateral deviations. Besides the effects of lateral offset, greater delta-V also contributes to greater post-impact motions and shorter lane departure time. The effect of greater delta-V is exemplified in a comparison of cases with different operating speeds. This study evaluates the consequences of collisions beyond the one-dimensional analysis suggested in previous studies. It provides additional information to help understand post-impact vehicle dynamics. With inputs from studies of this type, the evaluation of safety issues in AHS may be pursued by using a simpler one-dimensional model for macroscopic assessment and more complex simulations for detailed representation of specific conditions. (A)
Abstract