EU car black box: what the data recording system logs and how it works

The European Union is continuing its drive to improve road safety. As part of that effort, it made a number of systems mandatory for cars launched from July 2022. One of the most debated additions is the data recording system - the “car black box”.

Modelled on a technology that has long existed in aircraft, it has also attracted criticism from those who argue it could amount to a potential breach of data protection law.

Even so, from next year this system will be compulsory. To clear up the remaining uncertainty around the “black box” that will be fitted to cars, this article sets out what it is and how it operates.

Why the EU is mandating a car “black box”

Although the feature is often compared with an aircraft black box, its purpose in road vehicles is different. Its role is to capture technical information around a collision so that accidents can be analysed more clearly afterwards.

The data recorded

First, it is worth putting to rest the misconception that this system will be able to record conversations inside the car. While that may be true in aviation, the “black box” used in cars will, in some respects, be closer to the tachograph used in heavy goods vehicles (effectively a 21st-century tachograph).

The data recording system will primarily log what we generally refer to as telemetry.

• Accelerator pedal pressure or engine revolutions;
• Steering angle and angular speed in degrees;
• Speed over the last 5 seconds;
• Brake use;
• Delta V duration (positive or negative acceleration);
• Airbag activation and seatbelt pretensioners;
• Seatbelt use and the occupants’ dimensions;
• The change in speed the vehicle experienced after the impact;
• Longitudinal acceleration in metres per second squared (m/s²).

The main purpose of this system is to enable accidents to be “reconstructed”, with the aim of making it easier to determine responsibility.

Ending impunity

At present, working out whether a driver was speeding before a crash requires various measurements and expert assessments. In future, it should be enough to access the “black box”, with the car itself providing that information.

Even more valuable will be the ability to confirm whether passengers were wearing seatbelts - something that is not straightforward to establish today. On top of that, some argue these data could also help car manufacturers improve their safety systems.

Volvo and accident research

The Volvo Car Accident Research Team reviews data from certain accidents involving the Scandinavian brand’s models in order to improve the safety of future vehicles. With this system, the work of the Swedish technicians will be far simpler than it is today, as you may remember from that article.

Privacy and access to the event data recorder

As for privacy concerns, the European Union’s intention is that these data are only consulted in the event of an accident. Moreover, there is nothing to suggest these devices will be able to transmit the recorded data; instead, they are designed to store it until it needs to be accessed.

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