The Simulation Model of Automobile Collisions (SMAC) computer program has been developed for the purpose of achieving uniformity in the use of analytical techniques for interpretation of physical evidence in investigations of highway accidents. The comprehensive output information of the SMAC program (kinematics, tire tracks, and vehicle damage) permits extensive, detailed comparisons with physical evidence in the iterative runs used to achieve a “best fit,” and the predicted vehicle responses provide a basis for relatively refined categorization of occupant exposures. The generality included in the inputs of the SMAC program permits approximation of the effects of driver control inputs, damage to vehicle running gear, and traversal of terrain zones with different friction properties.

The analytical approach is outlined, and specific assumptions are defined. Comparisons are presented between analytical predictions and results of staged collisions. In one of the presented applications to a staged collision, the initial conditions were kept unknown until completion of the reconstruction process. Results of sample applications to actual highway accidents are included. Computer graphics displays of reconstructed accidents, including rest positions, tracks, and damage, are presented.