Event Data Recorder (EDR or Black Box)

The event data recorder (EDR), or “black box” is a piece of hardware found in vehicles that collects numerical data regarding the activity of the vehicle and the driver. This device can be found in 40 million cars in the United States alone, though many people do not even know the machine is there. EDRs have been installed in cars since the early 1990s, and it is estimated that 85 percent of the new cars released this year will contain a black box. EDRs have been used in planes for as long as they have been in commercial use, and have only recently been applied to cars. Although the EDR helps trigger the airbag, it is not a necessary component. It is often used in safety investigations, but only as a means to reinforce previous findings and calculations. International standard regulations regarding EDRs were established in 2004.

At any given time, the EDR is monitoring a vehicle’s speed, braking, and seat belt use, but only retains the last five seconds before the airbag is deployed. Depending on the model of the car, this data may only be available to the car manufacturer, who will often refuse to release the data without a police warrant. However, because the data stored in an EDR is accessible through crash data retrieval (CDR) software, it can be easily downloaded by a mechanic. It is best though, to hire a forensic engineer whose expertise would be more readily accepted in court. As CDR software has evolved, EDRs have been used more frequently in lawsuits, and are often the deciding factor in a case.

The EDR, however, is not a completely infallible device. It can easily experience malfunctions due to software failure, faulty automobile electrical systems, or ineptly extracted data. The information is often accidentally deleted, either by overriding the evidence with more recent data or when a mechanic performs a software cleanup without following forensic protocols. When the National Highway Traffic Safety Administration performed a study on 700 vehicles using the black box, approximately 40 percent of the cases experienced difficulty in retrieving the data. This statistic prevents the EDR from becoming a forensic staple and it, as of yet, cannot replace the vehicular accident reconstruction of a forensic engineer.

Another complaint against the EDR is the issue of privacy. Some do not wish to own a car that implicates them when they are at fault in an accident. Others believe that they are being subjected to involuntary surveillance. Typically, law enforcement officers are required to produce a warrant in order to view the data in a black box, while the NHTSA is drafting an amendment to protect drivers against data tampering and odometer fraud.

The EDRs used in heavy vehicles, such as trucks and buses, are somewhat more reliable than those used in smaller vehicles. They have a larger capacity for storage so they record data up to thirty seconds before an accident and fifteen seconds after a crash. They also record the data more often so that more precise measurements can be used to determine position, speed, and acceleration. Depending on the manufacturer, the EDR may record the use of brakes, clutch, throttle, and cruise control, as well as determine the engine load. Though this data can also be accidentally erased, the data itself is typically more accurate and precise than EDRs in smaller vehicles.

Heavy Truck EDR. 2010. http://heavytruckedr.org/index.html

Hobson, M. “Is That a 'Black Box' in Your Car? A Useful Tool for Law Enforcement but Some Worry Their Cars Might Rat on Them”. ABC News. http://abcnews.go.com/Technology/MellodyHobson/car-black-box-records-key-data/story?id=9814181&page=2.

Jones, A. 2010. “Will Toyota’s ‘Black Boxes’ Prove Fruitful for Plaintiffs’ Lawyers?” The Wall Street Journal. http://blogs.wsj.com/law/2010/02/16/will-toyotas-black-boxes-prove-fruitful-for-plaintiffs-lawyers/tab/article/.

Maynard, M. 2010. “Agency Weighs the Need for a ‘Black Box’ in Cars”. The New York Times. http://www.nytimes.com/2010/03/12/business/12toyota.html.

Sharp, D. 2003. “Autos' black-box data turning up in courtrooms”. USA Today. http://www.usatoday.com/news/nation/2003-05-15-boxes-usat_x.htm.