Study on a Method for Reconstructing Pre-Crash Situations Using Data of an Event Data Recorder and a Dashboard Camera

When investigating traffic accidents, it is important to determine the causes. To do so, it is necessary to reconstruct the accident situation accurately and in detail using objective and diverse information. We propose a method for reconstructing the accident situation (“reconstruction method”) which consists of rebuilding the situation immediately before the collision (“pre-crash situation”) using data collected during that time by an event data recorder (EDR) and a dashboard camera (DBC) onboard one or both of the vehicles involved. First, the vehicle’s traveling trajectory was integrally calculated using the vehicle speed and yaw rate recorded by the EDR, each point along the trajectory being linked to the EDR data. After being combined with the DBC’s video data, the trajectory was projected onto the road surface around the accident site, which allowed us not only to display on a single road map the vehicle’s traveling trajectory, but also to provide, on each point along the trajectory, diverse information from EDR data and freeze-frame pictures of the road ahead from the DBC. The reconstruction method was then applied to a real-world accident involving the collision of two vehicles at an intersection. The analysis of the reconstructed accident situation showed that the Advanced Emergency Braking System (AEBS) of one of the vehicles was not designed to be activated in this collision scenario. Using this reconstruction method, objective and diverse pieces of information (collected by EDRs and DBCs) and traveling trajectories obtained from traffic accident investigations were projected onto a road map in a chronological and integrated way to reconstruct the pre-crash conditions as accurately and in as much detail as possible. Further, if one or both vehicles involved in the accident had the EDR’s pre-crash data and the DBC’s images regarding an advanced driver assistance system (ADAS), this reconstruction method allows us to easily understand the pre-crash situation through the diagram that reconstructed how the ADAS was working (EDR data) and the position of the other vehicle ahead immediately before the accident (DBC images).