EDR- What is an Event Data Recorder and What Do They Tell Us About a Car Accident?
An event data record (EDR), also known as a vehicle’s black box, is a device installed in most vehicles that record technical information about the vehicle and the occupants for a brief period of time before, during, and after a crash. For example, the EDR will record a vehicle’s speed, engine RPM, and certain driver input such as brake application, steering wheel angle, and throttle position right before a crash. It will also record information during the crash such as the delta-v, also known as the change in velocity, airbag deployment, and seatbelt usage. Lastly, it will also record certain post-crash events such as secondary impacts, fires, and whether the Advanced Automatic Collision Notification was activated. The Advanced Automatic Collision Notification automatically notifies emergency services of the crash along with crucial information such as the severity of the impact, the number of occupants in the vehicle, and if the airbags were deployed.
The data from a vehicle’s black box can be crucial in a car accident case. It will give us details about what the driver did right before the impact which can help prove if the driver was negligent or not. It will also tell us how severe the impact was.
One of the most important data that the EDR will record is the delta-v, or change in velocity. This is not the change in speed of the vehicle. Speed and velocity are two different measurements of motion. Speed is simply the rate an object covers distance. Velocity, on the other hand, measures the rate an object changes its position, either in the same direction or in a different direction. So, speed equals the distance traveled divided by the time taken to travel the distance. Velocity equals the change of the position divided by the time taken to change position. In simple terms, speed is how fast an object is going and velocity is how fast an object is going in a certain direction. If an objection changes speed, direction, or both, there is a change in the velocity. The delta-v of a car involved in a crash will tell us how severe the impact was because it tells us how its motion changed in terms of both speed and direction.
All this information will assist an accident reconstruct expert tell the story of happened before, during, and after a crash. An accident reconstruction expert will be able to determine the speeds and directions of the vehicles before, during, and after the crash. With this information, the expert will be able to recreate the series of events for the jury. Basically, the expert will create a reenactment of the accident. Furthermore, an accident reconstruction expert will assist a biomechanical engineer by providing them with reliable data regarding the speeds and directions of the vehicles involved in the accident so the biomechanical engineer can than evaluate how the impact may have affected an injured person’s body.
In conclusion, the EDR data of a vehicle can make or break a case. It is a useful and decisive tool to measure the severity of the impact, reconstruct the accident, and evaluate how the impact caused or didn’t cause an injury.