Justin P. Schorr, Ph.D., Principal Collision Reconstruction / Transportation Engineer
Multi-vehicle collisions, sometimes involving dozens of vehicles, typically occur during periods of adverse weather conditions such as snow, ice, and/or fog (some may recall the recent 20+ vehicle collision in Pennsylvania). When these collisions occur on high-speed, limited-access highways, there can be severe consequences as a result of the multiple impacts (at the time of this writing it has been reported that there were 2 fatalities and over 35 people sent to the hospital as a result of the aforementioned pile-up in Pennsylvania). However, from a reconstruction standpoint, with so many vehicles involved, how does one define the dynamics of the collision?
Laurence R. Penn, Senior Forensic Animation/Video Specialist ::::
Thanks to powerful software, forensic video specialists at DJS Associates are able to analyze surveillance and dashcam video footage in three dimensions, with high levels of accuracy, in order to reconstruct the circumstances of an accident. Although multiple factors may complicate the process, tenacity and an eye for detail can yield rewarding results. In this case study, the original dashcam video footage showed evidence of lens distortion which needed to be corrected in order to proceed with detailed videogrammetric analysis. After a few phases of lens correction, environment features represented by the red crosses were placed in the undistorted video frame and matched to their locations in the 3D scan data. Once refined the virtual camera is placed accurately within the 3D environment. Trackers represented by the green and yellow crosses were placed on features of the vehicles for each frame in the video. Again, these positions were matched to their relative locations on the 3D vehicle scan data. The final analysis allows 3D vehicles to be placed in the 3D environment spatially and temporally in order to view the circumstances from alternate angles, and even from the operators or eye witness point of view.
Laurence R. Penn, Senior Forensic Animation/Video Specialist at DJS Associates, can be reached via email at experts@forensicDJS.com or via phone at 215-659-2010.