Event Data Recorder: The Black Box for Vehicles

Author: Michael Vogel

Mar 06, 2024

Some 70 years ago, the Flight Data Recorder for airplanes was invented. The Event Data Recorder (EDR), an accident data recording device for vehicles, will be mandatory in the EU by mid-2024. Despite the differences in technologies, both help to improve accident analysis.

Initially, David Warren’s idea was met with little approval from his superiors. Warren, an engineer at an aviation research laboratory of the Australian Department of Defense, was originally developing fuel tanks. However, after being part of a commission investigating two plane crashes, he came up with a solution that would allow the recording of conversations in the cockpit, aiming to reliably determine the causes of crashes. This was in 1954. The engineer’s subsequent boss eventually indulged in Warren’s idea and allowed him to develop a prototype of the Flight Data Recorder, which then caught the attention of the British Civil Aviation Authority.

The Black Box’ Success Story

That marked the breakthrough for the Flight Data Recorder, a.k.a. black box. In 1963, Australia became the first country to introduce mandatory data and voice recorders for all aircrafts. Other countries soon followed suit. Today, the black box, which is actually red or orange, is a standard feature – and has helped get to the bottom of many accidents. Warren is generally considered the inventor of the black box, even though there were similar developments in various countries during and after the Second World War.

Mandatory EDR for new cars from July 2024

The automotive equivalent of the Flight Data Recorder will be mandatory in all new cars registered in the EU by July 2024. Officially, this black box is called the Event Data Recorder (EDR). It does not have to withstand the enormous forces of a plane crash and it does not record conversations, as is the case in the cockpit. An airplane is a means of public transport, which is subject to an entirely different data protection framework than a private vehicle. Still, the two devices are similar in one respect: The recorded data makes it possible to reconstruct accidents more reliably.
The EDR continuously records relevant data, but only permanently stores it when detecting a change in longitudinal or lateral direction of more than eight kilometers per hour within 150 milliseconds. Without this triggering signal, the recorded data will be overwritten repeatedly.
The device saves data on longitudinal and lateral speed progression, accelerator and brake pedal position, engine speed, steering angle, as well as information on the anti-lock braking system, and stability control. It also records whether the passengers are wearing seat belts, as well as the activation of seat belt tensioners and airbags. The EDR is often integrated into the airbag control unit, as this is where much of the required information is collected anyway. The stored data cannot be extracted wirelessly, but only via a physical maintenance interface.

European accident research relies on accident analysis data

Data such as that provided by the EDR is no new territory for accident research in Europe. “It was already being collected in vehicles, but there was no standardized technical and legal framework for storage and evaluation,” says Peter Rücker, Head of Accident Analysis and Accident Research at DEKRA. “However, we have been using such data for several years to analyze complex or controversial accidents – if we have the owner’s consent or a court order.” For data access, Rücker and his team have often had to rely on the cooperation of the manufacturer of the affected vehicle.

“EDR data could turn out to be the missing puzzle piece.”

Peter Rücker, Head of Accident Analysis and Accident Research at DEKRA
“You might think that in future, experts will simply read out the EDR to analyze an accident,” says Rücker. “But that’s a misconception, because of course an EDR only provides data, not assessment and interpretation. It is also important to know where and how the data is measured.” If, for example, the wheel of a vehicle is spinning freely in the air, the speed data taken at the wheel is of little use. EDR data should also be treated with caution if a vehicle is skidding at right angles to the direction of travel. “That’s why we see EDR data as another pillar to support the tried-and-tested analysis methods, nothing more, nothing less,” Rücker states.

Shedding a light on multiple collisions

One scenario in which EDR data is expected to provide more clarity are rear-end collisions involving several vehicles on freeways. “In multiple collisions, the determination of fault always revolves around when and where which vehicles came to a stop,” Rücker explains. “EDR data could turn out to be the missing puzzle piece.”
Incidentally, the EU is not alone in introducing the EDR. Over the past two decades, other countries have introduced similar systems, albeit with varying legal frameworks. These countries include the USA, Japan, and South Korea – and more recently China. There is also a UN guideline aiming for global harmonization of EDRs.
The black box in cars could now spread as quickly as the Flight Data Recorder did back when – despite Europe’s ever prevailing skepticism regarding privacy. Incidentally, people had similar concerns about the Flight Data Recorder. The Australian Federation of Air Pilots, for example, described the prototype presented by Warren as a “spy on board”. No plane will take off in Australia if “Big Brother is listening”.