Validation of SynthEyes for use in Collision Reconstruction

Accurate reconstruction of vehicle collisions is critical for understanding incident dynamics and informing safety improvements. Traditionally, vehicle speed from dashcam footage has been approximated by estimating the time duration and distance traveled as the vehicle passes between reference objects. This method limits the resolution of the speed profile to an average speed over given intervals, minimizing vehicle accelerations. A more detailed speed profile can be calculated by tracking the vehicle’s position in each video frame; however, this method is time-consuming, can introduce positional error and variable frame rate noise, and is often constrained by the availability of external trackable features in the surrounding environment. Motion tracking software, widely used in the visual effects industry to track camera positions, has been adopted by some collision reconstructionist for determining vehicle speed from video. This study examines the accuracy and reliability of using one such 3D tracking software, SynthEyes, for this purpose. Dashcam footage of a VBOX-equipped test vehicle was processed using SynthEyes to track camera positions and calculate vehicle speed. The resulting speed profiles were analyzed and compared to the VBOX’s high-accuracy GPS data. Signal processing methods were explored and evaluated to determine which, if any of the filtering techniques best approximated the actual speed profile of the vehicle. The findings indicate that SynthEyes provides a viable technique for speed estimation in collision reconstruction, with potential errors minimized through appropriate filtering. The software can be a valuable tool for forensic engineers and accident reconstruction professionals.