Frequently Asked Questions

Is the Event Data Recorder (EDR) the same thing as the Black Box?

EDR is a term coined by the National Highway Traffic Administration (NHTSA) to refer to a device installed on motor vehicles which records technical information regarding an impact.  The EDR records information shortly before, during and after an impact.  The EDR is commonly referred to as the Black Box.  There are other types of vehicles, such as airplanes and trains which have recorders which are referred to as Black Boxes, but these devices continuously record and may also have other functions, such as recording sound.

Do all vehicles have EDRs?

It is estimated that 64% of 2005 model year vehicles have EDRs.  For model year 2013 vehicles, it is estimated that 96% of vehicles have EDRs.  If the vehicle in question is from this century, it is likely that vehicle has an EDR.

What does the Black Box record?

EDRs typically record 5 seconds of pre-crash data, which includes vehicle speed, throttle percentage, engine speed, brake usage, ABS activation, steering wheel angle, traction control activation and much more.  EDRs also record seat belt usage, ignition cycles at the event and download, seat position and other time independent data.  EDRs also record crash pulse data, which is a time history of the accelerations and speed changes experienced during the crash.

Manufacturers have the freedom to record almost whatever technical data they wish, but the following data elements are required to be recorded:

• The forward and lateral crash force.
• The crash event duration.
• Indicated vehicle speed.
• Accelerator position.
• Engine rpm.
• Brake application and antilock brake activation.
• Steering wheel angle.
• Stability control engagement.
• Vehicle roll angle, in case of a rollover.
• Number of times the vehicle has been started.
• Driver and front-passenger safety belt engagement, and pretensioner or force limiter engagement.
• Air bag deployment, speed, and faults for all air bags.
• Front seat positions.
• Occupant size.
• Number of crashes (one or more impacts during the final crash event).

What types of crashes are recorded by the Black Box?

Prior to 2014, EDRs primarily recorded frontal impact data.  Since then, all vehicles in which EDRs are installed, are required to record frontal, side and rear impact data for all events in which the vehicle experiences a speed change of at least 5 mph occurring over 150 ms or less.  Some EDRs record events with even smaller speed changes.  EDRs also record data during rollover events.

How long the Black Box store data?

It is a common misconception that EDR data will disappear after a short period of time.  Events which trigger the Airbag Control Module (ACM) are written to memory indefinitely.  In the event of an airbag deployment, this data is permanently written to memory and cannot be overwritten.  Events which do not cause an airbag deployment are also written to memory indefinitely, but these events (non-deployment events) can be overwritten by subsequent non-deployment events.  It is common for an EDR to have enough memory to keep three events in memory before a fourth event overwrites the least recent event.

What is the Black Box data used for?

EDR data can be used to determine many things.  One such usage of EDR data is to determine aspects surrounding a crash, such as driver inattention.  The lack of pre-impact braking and steering may be indicative of this.  EDR data can also be used to determine the severity of the crash.  The recorded crash pulse data can be used by a biomechanical engineer to evaluate the injuries produced or claimed in a crash.

Who owns the Black Box data?

The Driver Privacy Act of 2015 declares that any data in an event data recorder required to be installed in a passenger motor vehicle is the property of the owner or lessee of the vehicle in which the recorder is installed, regardless of when the vehicle was manufactured.

Who may access the Black Box data?

The Driver Privacy Act of 2015 prohibits a person, other than the owner or lessee of the motor vehicle, from accessing data recorded or transmitted by such a recorder unless:

• a court or other judicial or administrative authority authorizes the retrieval of such data subject to admissibility of evidence standards;
• an owner or lessee consents to such retrieval for any purpose, including vehicle diagnosis, service, or repair; the data is retrieved pursuant to certain authorized investigations or inspections of the National Transportation Safety Board or DOT;
• the data is retrieved to determine the appropriate emergency medical response to a motor vehicle crash;
• or the data is retrieved for traffic safety research, and the owner’s or lessee’s personally identifiable information and the vehicle identification number are not disclosed.
• Directs the National Highway Traffic Safety Administration, after completing a study and submitting a report to Congress, to promulgate regulations concerning the amount of time event data recorders installed in passenger motor vehicles may capture and record vehicle-related data to provide accident investigators with pertinent crash-related information.