An event data recorder is the device, often called a car’s “black box,” that records information such as speed and braking in the seconds before a crash.
An EDR is usually part of a vehicle’s airbag or restraint-control system rather than a separate dashboard gadget. It can capture items such as vehicle speed, accelerator position, brake application, seat-belt status, airbag deployment and changes in velocity during the collision.
The nickname is borrowed from aircraft flight recorders, but an automotive EDR is not a continuous audio or video recorder. It generally stores a short loop of technical data and preserves the relevant segment when a sufficiently severe crash occurs. The exact data set varies by vehicle and manufacturer.
EDR data can help investigators reconstruct what happened, but it is not the same as information from a GPS tracker, telematics unit or diagnostic scanner. In the United States, federal rules for vehicles equipped with EDRs standardized many data elements and applied to covered vehicles manufactured from September 1, 2012.