Event data recorders in the analysis of frontal impacts

Evaluations of crash protection safety features require measures for quantifying impact severity. Velocity change (delta-V) is the major descriptor of collision severity used in most real-world crash databases. One of the limitations of delta-V is that it does not account for the time over which the crash pulse occurs (delta-t). Late model GM vehicles equipped with event data recorders capture the cumulative delta-V in 10 ms intervals over the crash pulse. Deceleration can be readily calculated from these data and provides a complementary measure of severity that has not previously been available for real world crashes. The relationship between maximum delta-V and deceleration was examined for different vehicle platforms involved in real world frontal impacts and frontal crash tests. Maximum deceleration was observed to be closely correlated to the maximum delta-V.