Abstract
An automotive accident reconstruction treatment is presented which includes momentum and energy changes over the estimated duration of the impact, due to the forces generated by unsteered and undamaged tyres. These tyre forces are computed from the stipulated average braking and from the variable slip angles found by interpolation between the iteratively determined initial and final states of motion. The precision of the resulting momentum solution justifies also finding magnitudes and ratios of shear-plane speed and force at the impact centroids, to guide the correction of errors of observation and allow the imposition of known shear and rebound constraints. (A)