How long does EDR data last? Before I go further with this question, I want to make sure we're all on the same page with regards to what EDR data is.

What is EDR data?

EDR is short for event data recorder, and most modern vehicles are fitted with an EDR recorder. EDR data is data stored by the vehicle in the event the vehicle is involved in a collision.

How long does EDR data last?

The length of time EDR data lasts depends on a number of factors, such as event type and whether it resulted in a collision or a near miss, how many times the engine has been started or the ignition cycled or even if the vehicle is involved in a new incident which causes old data to be overwritten. It is also worth remebering that it is possible to manually remove collision data but this requires specialist knowledge and tooling.

What is an EDR near miss event?

There are no hard and fast rules around what a near miss event is and each manufacturer will have their own definition of what constitutes a near miss event. Generally speaking however, a near miss event occurs when the vehicle, through various sensors, detects a movement which it believes may result in the deployment of an airbag or other safety system. As the event unfolds, the need to deploy the airbags or safety systems doesnt materialise (for whatever reason). This sometimes results in a record being stored in the EDR.

By way of an example, you are driving down the road when a pedestrian steps out, you brake so hard that your hazard lights automatically illuminate, but before a collision occurs, the pedestrian steps back onto the pavement. You as the driver release your foot brake and carry on your journey. No collision has occurred, but there was a time where the vehicle thought it might have to deploy the airbags or one of the safety systems.

When should you recover EDR data?

Our advice is always the same, recover EDR data as soon as possible. Firstly, the earlier you recover the data, the less likely you are to lose it or overwrite it. Secondly, whilst some vehicles record events onto the EDR with a time and date stamp, other vehicles use different methods which are less precise, such as ignition cycles. The quicker you download the data, the closer the ignition cycle is at the time of the event to the time when the data was recovered. It allows you to demonstrate the relevance of the data.