Forensic Engineering Analysis of Vehicle-Pedestrian Impact Using EDR Data and Reconstruction Software

Abstract

This paper will analyze a pedestrian impact with a 2012 vehicle in a criminal matter. The driver of the vehicle struck the pedestrian before crashing into a chain-link fence and tree. The driver was arrested and charged with vehicular homicide and driving while intoxicated (DWI). The question was: Where was the pedestrian standing when she was struck? The airbag control module was downloaded by the prosecution expert. The speed, steering angle, and longitudinal/ lateral accelerations were recorded for a period of 5 seconds prior to algorithm wake-up as a result of a fence side-swipe and then algorithm enable (AE) for the deployment of the vehicle-side airbags after impacting a tree. The recorded data was input into Virtual Crash and PC-Crash (accident reconstruction software that uses Newton’s laws of motions in analysis). The software allowed the time-distance-speed path of the vehicle to be visualized. The prosecution expert opined that the pedestrian was struck on the sidewalk a short distance from where she came to rest. This author was retained by the defense to determine the pedestrian’s posi-tion — either in the roadway or on the sidewalk.