A built-in vehicle device that captures a short burst of technical information before, during, and after a crash, such as speed, braking, throttle use, seat belt status, and airbag deployment.

Often called a vehicle "black box," it does not usually record everything that happened over a whole trip. Instead, it preserves seconds of data tied to a triggering event like a sudden impact or near-deployment of safety systems. In a crash investigation, that data can help show whether a driver braked, how fast the vehicle was moving, whether an occupant was belted, and how forceful the collision was. That makes it useful alongside accident reconstruction, skid mark analysis, vehicle damage, and witness statements.

For an injury claim, an event data recorder can support or undermine key arguments about fault, causation, and the seriousness of the impact. In heavy-traffic corridors like Montgomery County's DC commute routes, where chain-reaction collisions are common, recorder data may help sort out timing and driver actions when stories conflict. It can also affect disputes over whether a crash could have caused a claimed injury.

Maryland does not have a single special crash-law deadline aimed only at event data recorders, but the evidence can be lost if a vehicle is repaired, salvaged, or destroyed. Preserving that data early may require a spoliation letter, and access may depend on consent, a court order, or other lawful process.