Standards For Motor Vehicle Black Boxes

Starting in the 1970's, General Motors introduced a rudimentary event data recorder (EDR) in its airbag-equipped vehicles, to record basic data about airbag deployment. Over the subsequent decades, more automobile manufacturers introduced EDRs into their vehicles, and the devices became more sophisticated.

Most cars now on the road contain an EDR, commonly known as an automobile black box.

Federal Regulations

Every new car sold in the United States is now required to include an EDR, with federal regulations dictating the minimum information that must be recorded.1 Federal regulations also require that the presence of an EDR be disclosed in a vehicle's owner's manual.2

In simplified terms, under federal regulations an automobile black box must record and preserve the following information in the event of a vehicle crash:

  • The duration of the crash event;
  • The number of crashes, if there was more than one impact during the crash event;
  • The vehicle speed as indicated on the speedometer;
  • The position of the accelerator pedal;
  • Engine RPM;
  • The angle of the steering wheel;
  • Whether the brakes were applied, and if antilock brakes were activated;
  • The forward and lateral crash force during the crash event;
  • Whether stability control was engaged;
  • If the crash event involved a rollover, the rollover angle;
  • Whether the Driver and front seat passenger safety belts were engaged;
  • Whether front seat belt pretensioners or force limiters were engaged;
  • The positions of the front seats;
  • Occupant size of the driver and front seat passenger;
  • The number of times the vehicle has been started; and
  • Air bag deployment and time to deploy.

The data is to be preserved for the period of time preceding the accident, the duration of the crash event, and for a period of time following the accident. The total period of time recorded is usually thirty seconds or less.

The Problem With the Federal Regulations

Although federal regulations allow for the recording of a considerable amount of information that may be useful to determine how an accident occurred, and thus to improve road and vehicle safety, the regulations do not address some important issues:

  • Privacy: Although federal regulations now require that vehicle manuals disclose the presence of black box devices, they do not provide any privacy rules or standards for the data recorded on the EDR.

  • Quality: The federal regulations describe information that must be recorded, but do not set any standards that will ensure the accuracy or quality of the information;

Some states have passed laws that create privacy rights in EDR data, or restrict the use of the data in court.

Older Vehicles

The problems of EDR data are compounded in older vehicles, those manufactured before the 2015 model year, as the types of data recorded, the duration of the recording, and the format of the data were left up to the vehicle manufacturer. Thus, even as EDRs became common, the completeness, accuracy and usefulness of the information contained on any given EDR from any given vehicle could be radically different.

Although federal regulations have introduced greater consistency, there remains plenty of room for improvement.


  1. 49 CFR 563.7

  2. 49 CFR 563.11.

Copyright © 2016 Aaron Larson, All rights reserved. No portion of this article may be reproduced without the express written permission of the copyright holder. If you use a quotation, excerpt or paraphrase of this article, except as otherwise authorized in writing by the author of the article you must cite this article as a source for your work and include a link back to the original article from any online materials that incorporate or are derived from the content of this article.

This article was last reviewed or amended on Apr 13, 2018.