More and more investigations by the police are including data from the Event Data Recorder. Event Data Recorders are also known as EDRs or little black boxes.
EDRs are installed on most newer cars and record information regarding speed and braking prior to an accident. This data becomes part of the accident investigations.
The National Highway Traffic Safety Administration (NHTSA) wants even more data preserved. This is clearly going to be a big issue in disputed liability cases in the future.