In recent decades, the manufacturers of motor vehicles have installed Event Data Recorders (EDRs) in most new vehicles. Under present federal regulations, all new vehicles sold in the United States must include an EDR.
These devices have come to be known as automobile black boxes. However, unlike their informal namesake, the black box used in aircraft and analyzed after aviation accidents, automobile black box data is much less reliable for purposes of determining accident causation.
Data from vehicle EDRs has been used in traffic court cases, to establish whether or not a traffic violation occurred. Due to the cost and complexity of recovering the data, the data from a vehicle's EDR is rarely used in traffic court unless the case involves an accident.
Even in the event of an accident, most tickets are issued and decided based upon evidence from the accident scene, without any attempt to recover or use information from the EDR. For example, when using data from a black box that complies with current regulations:
Where drivers accuse each other of speeding, or where there is a traffic accident fatality, EDR data may establish whether a driver is being honest about his own speed or that of the other driver;
If a person claims that he was in the passenger seat of a vehicle that was involved in a crash, and that the actual driver ran off after the accident, the EDR will reflect whether or not the front passenger seat was occupied;
If a person claims that he was operating a vehicle within the speed limit, the EDR may contain data showing that the driver was significantly exceeding the speed limit during the seconds prior to an accident;
In one well-known incident, the lieutenant governor of Massachusetts was involved in a single car accident in which he claimed to have been observing the speed limit before losing control on ice. EDR data established that the vehicle had been traveling at 108 MPH at the time of the accident.
Data has also been used in civil cases, both to try to establish liability on the part of a person alleged to have caused a traffic accident, and to defend against claims of liability both by drivers accused of negligence, and by manufacturers accused of producing defective vehicles or vehicle parts.
In a case involving a defective vehicle claim, a driver who claimed that his vehicle was spontaneously accelerating and could not be stopped was shown to have been depressing the accelerator pedal and only lightly pressing on the brake pedal;
Where a driver alleged that her accident was caused by the spontaneous deployment of the driver-side airbag while she was driving, EDR data established that the airbag did not deploy until after the collision occurred;
In a case that alleged defective airbags, although the occupants of the vehicle asserted that the collision occurred at a high rate of speed, the EDR recorded a speed below that which would have been necessary to trigger airbag deployment;
In some cases it might even be possible to use black box data to help prove or disprove that certain injuries, alleged to be caused by a motor vehicle accident, could have been caused by the accident.
As the motor vehicle EDR was designed to improve vehicle and driver safety, and not to establish the causation of accidents or responsibility for traffic tickets, issues may arise with the use of the data in court:
Accuracy: As there are no quality standards beyond those voluntarily adopted by the manufacturer, questions may be raised as to the quality or integrity of the data contained on an EDR;
Preservation of Evidence: If a car is totaled, the EDR may be destroyed before the parties to a lawsuit or their lawyers realize that it may contain valuable information about the accident;
Problems with Data Recovery: Particularly for vehicles that predate the federal regulations, data recovery may be complicated by the proprietary nature of the recorders and data.
Due to inconsistency and lack of quality standards, care must be taken when using vehicle EDR data to try to establish causation for an accident.
Data from the recorder may be misleading if taken at face value. The vehicle's recorded speed, for example, will reflect the rate at which the wheels are spinning and not the actual velocity of the vehicle.
All evidence from an accident should be considered, with the EDR data being used to supplement the accident investigation, not as a substitute for traditional accident investigation and reconstruction.