A black box, also known as an Electronic Control Module (ECM) or Event Data Recorder (EDR), is a computer device installed in most modern vehicles that automatically records important information about how a car was being operated in the seconds before, during, and after a crash. This device captures data such as the vehicle's speed, whether the brakes were applied, if seat belts were fastened, the angle of steering wheel turns, and whether airbags deployed, essentially providing an objective record of what happened during an accident. Unlike airplane black boxes, car black boxes typically only store data for a few seconds around the time of impact, but this brief window can provide crucial evidence about how an accident occurred.
In personal injury cases, black box data can be extremely valuable evidence for determining fault and understanding the severity of a crash, especially when the people involved have different stories about what happened. This electronic evidence is considered highly reliable because it's generated automatically by the car's computer systems and cannot be altered after the fact, making it much more trustworthy than human memory or eyewitness accounts. However, this data can be lost or overwritten if not retrieved quickly after an accident, so personal injury lawyers often move fast to preserve black box evidence, and both sides may need to hire technical experts to download, analyze, and explain what the data means to judges and juries.
