Event data recorders: an impartial witness

High level data from real-world collisions regarding crash severity, pre-crash speeds, perception and reaction, evasive inputs and seatbelt use are of great importance in the resolution of legal issues and are critical data elements to researchers conducting studies into vehicle collisions. Many late-model General Motors light-duty vehicles are equipped with event data recorders (EDRs) that capture data relating to the crash pulse, the time history of the velocity change, and in some cases the time history of a number of pre-crash data elements including vehicle speed, brake switch status, throttle position and engine speed. The objective of this research is to examine the role of the EDR in the reconstruction and understanding of fatal crashes. Thirteen real world collisions involving a driver fatality in a vehicle equipped with an EDR were studied. In each case a detailed collision investigation and reconstruction was conducted to determine the crash events and validate the recorded data. The EDR data greatly improved the understanding of pre-crash events and often provided critical insight that otherwise would have remained unknown.