Black Boxes in Cars: How do These Devices Work?

In 2022, all new vehicles marketed on European soil will have to compulsorily equip a system that records all the data of our trips so that they can be used in the event of an accident. We are talking about the so-called black boxes for cars, similar to those carried by planes, although without the ability to record images or audio. And although neither are black, the big question is: How do they work?

If there is an accident, this device will record all the data during the 30 seconds before the accident and the five afterward. Thus, the speed, the behavior of the vehicle, the state of the safety systems (such as the use of the seat belt or the airbags), the location, the steering movements, the acceleration, and the deceleration, the participation of the ESP and ABS or even body roll angle. Therefore, investigating the accident involves connecting the aforementioned black box to a computer to obtain all the data.

This technology, called EDR (Event Data Recorder or Event Data Recorder), is usually located in the airbag control unit (on the dashboard or under the driver’s seat). Initially, the EDR was conceived to obtain information on the circumstances and how the airbags were activated to improve and optimize them. And although today they still do not capture images and sound, we cannot rule out that driver assistance systems based on artificial vision record the frames before a collision.

For now, the data collected by an EDR may vary depending on the vehicle manufacturer, model, and the device itself. However, they usually capture 15 or more variables monitored about 20 seconds before the crash and between 5 and 10 seconds after it. In addition to the parameters above, some EDRs also record the travel time, the time of day the accident occurred, and the route. Of course, everything is saved as long as the vehicle is on; an accident without contact does not retain any information.

What are black boxes in cars made of?

Bolted tightly to the chassis, the black car boxes are the size of a cigarette case, although steel is used instead of aluminum. It contains all the airbag system data network wiring and is connected to the passenger compartment data network. Inside there are a series of electrical capacitors responsible for providing the pulse of current necessary to activate the airbags in the event of an impact. Also, there is the central processor, some amplifiers, and a memory chip in which the last 35 seconds of travel are permanently recorded.

Legally, how does black box data influence?

It is not uncommon to have a dispute over who caused an accident. It is normal to hear accusations that the other car was going too fast or was clueless. Unfortunately, on many occasions, independent witnesses do not appear to share the memories of the events, and we are left with a typical case, “he said that the other said …”. However, thanks to the data recorded by the automotive black boxes, there is no grayscale, as it tells of everything that happened in the moments before and during the crash.

The information and data collected in the black box are encoded and protected so that specific tools and knowledge are required, both to extract the data and to analyze and interpret the data. It should be noted again that an EDR only records data in specific situations, and personal data such as the name, age, or sex of the driver are not stored. However, third parties such as the police could combine this information with the rest that is requested as identification during the investigation of a fan accident.

Of course, a black box can be accessed by almost anyone except you. Two things are required for this: physical access to the car and a dedicated system that allows data to be downloaded from a vehicle’s EDR by connecting a cable to the diagnostic socket (EOBD port).

Generally, the list of people with access includes your insurance company’s personnel (you permit them by accepting the clause that indicates that you authorize the company to collect as much information as it deems necessary during the investigation of an accident) and, logically, police. In the end, given that car black boxes will only collect information in a period before and after the accident, they allow us to reconstruct previous moments, know the causes of the accident, and evaluate the vehicle’s safety systems. The European Union (EU) considers that EDR technology is a handy tool for improving security. Also, all this information can positively influence drivers since we may try to improve by constantly evaluating our driving.

Special Mention RCC Auto Transport who support us to create this article.

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