Accident Reconstruction

Depending on the vehicle, model year, and recorder system, event data may include information such as indicated vehicle speed, accelerator or throttle input, brake status, change in velocity, vehicle dynamics, airbag deployment, and restraint-system status. In a reconstruction, those data can be compared with physical evidence, video, measurements, and other records while accounting for the recorder's recording interval, resolution, accuracy, timing, and vehicle-specific limitations. Retrieving crash data may also require vehicle-specific Crash Data Retrieval tools and procedures.

Speed analysis can draw from several sources, including tire marks, travel distances, video timing, vehicle damage, event data, and pre- or post-impact vehicle movement. Where supported by the evidence, reconstruction methods may apply braking, time-distance, momentum, energy, or other kinematic calculations to estimate speed or evaluate whether a proposed speed or range of speeds is physically consistent with the accident evidence.

Computer simulations can be useful when sufficient physical evidence and reliable input data are available to model vehicle movement or evaluate a reconstruction hypothesis. The inputs, assumptions, and model selected should be appropriate for the accident being analyzed, and simulation results should be compared with documented physical evidence. A simulation is an analytical tool and should not be treated as a substitute for reliable measurements, calculations, or scene documentation.