By John McEvoy, EIT

Personal dashboard cameras, or dashcams, have become more prevalent and important for the average driver on today’s roadways. They come in a variety of shapes, sizes and mounting options; whether it is a stand-alone camera unit, a GPS integrated system, or a replacement rear-view mirror with a forward-facing camera, there are many ways to ensure that roadway interactions are recorded and preserved on video. But how are these devices affecting the landscape of the insurance industry and forensic investigations?

Dashcams work by constantly saving small video files onto onboard or external memory drives until they are full, then continuing to record by overwriting the oldest recorded videos. Unfortunately, this means that the recorded videos are being constantly overwritten and thus there is the potential to lose the evidence if it is not gathered soon after an incident. However, most dashcams are also equipped with a collision detection feature – an accelerometer detects sudden changes in the velocity of the vehicle. If a certain threshold is passed, indicating a potential collision, the current video segment, and sometimes the surrounding video segments, are preserved. If the dashcam remains active, this prevents any video recordings from potential collisions from being overwritten, allowing the video to be obtained in the future, while still operating the camera in the meantime.

Dashcams have the ability to see and record the actions taken by an oncoming vehicle, determine the location of each vehicle during and leading up to an incident, or show that another driver performed unexpected or even malicious maneuvers intended to create a collision. Many dashcams can record audio as well, which could indicate what is happening inside the vehicle prior to and during an incident, and potentially record interactions between the involved parties following a collision. They are especially useful in cases involving pedestrian strikes, collisions where other information is limited, contradictory statements between involved occupants, or when vehicle damage is minimal.

Over 50% of the vehicles on the road today, and most new vehicles, are equipped with an Event Data Recorder (EDR) that can be downloaded by collision investigators. Depending on the vehicle make and model, the EDR captures data such as vehicle velocity, collision severity, steering input and seat belt buckle use. This data is used in collaboration with the physical evidence observed on the vehicles and the incident site to help reconstruct collisions. But what happens when a vehicle EDR data is not available? What happens when the collision severity is too low for the EDR to record a non-deployment event? Or perhaps there is minimal damage and no physical evidence left at the scene? While collision reconstructionists have many additional options when it comes to handling these cases, video footage analysis does a great job of filling in the gaps.

Analysis of dashcam footage can be utilized to determine a variety of additional and important factors in a collision. Interactive Driver Response Research can be used by reconstruction analysts to show what kind of reaction time would be expected from a driver depending on how a hazard presents itself. This research, used in tandem with a dashcam video, could show whether or not a responsible and attentive driver’s average reaction time would be sufficient to avoid a collision. Video analysis is also useful in yellow-light collisions when combined with the traffic signal timing from the intersection. Video analysis of the motion of other vehicles, pedestrians, or bicycles in the camera view can be used to determine their speeds leading up to the incident.

Dashcam videos are also useful for capturing footage of night-time collisions involving dark objects, vehicles without lights, or pedestrians in dark clothing. However, it must be remembered that the quality of the video captured may not reflect the actual conditions or light levels observed by the driver at the time. Night-time visibility studies are an important tool to determine the actual scenario that was presented to a driver. Depending on how the camera compensates for low-light conditions it may produce a video that shows a driver only had fractions of a second to react to a dark-colored object or pedestrian in dark clothing, but a visibility study may show that the driver should have been able to see the hazard for several seconds.

Dashcams are not the only source of video footage of an incident. Local homes, businesses, or third-party witnesses have their own security video feeds or personal videos available to help assist the investigator. This often can be sourced through the police investigation. Dashcams are an easy and inexpensive way for drivers to protect themselves and help determine the truth behind a collision. Analysis of dashcam footage can provide key evidence to corroborate a drivers’ statement of events, determine liability and defend against fraudulent claims.

Always remember to include any available video of an incident in the information you provide to your collision reconstruction analyst. CEP Forensic’s Collision Reconstruction team have the resources to analyze video data from multiple sources to aid in determining collision circumstances and driver response, when you have questions that need answered.

For more information or to talk about a claim with one of our experts, contact our Collision Reconstruction team at 877 686-0240 or

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