Validation of Vehicle Speed Analysis Utilizing the iNPUT-ACE Camera Match Overlay Tool

Traffic cameras, dash-cameras, surveillance cameras, and other video sources increasingly capture critical evidence used in the accident reconstruction process. The iNPUT-ACE Camera Match Overlay tool can utilize photogrammetry to project a two-dimensional video onto three-dimensional point cloud software to enable measurements to be directly taken from the video. Those measurements are commonly used, and critical for, the determination of vehicle speed in accident reconstruction. The accuracy of the Camera Match Overlay tool has not yet been thoroughly examined. To validate the use of the tool to measure vehicle speed for accident reconstruction, data were collected from a series of tests involving three traffic cameras, a stationary and moving dash-camera, a stationary and moving cell-phone camera, and a doorbell surveillance camera. Each camera provided unique specifications of quality and focal length to ensure the tool would be tested in a variety of scenarios. Vehicles drove past the various cameras at a variety of distances and angles with vehicle speeds that ranged from approximately 15.5 kph (9.6 mph) to 90.2 kph (56.1 mph) as recorded by a RACELOGIC VBOX GPS system. A bright flash was utilized to synchronize timing between VBOX and video data. The resulting comparison between VBOX data and the tool’s distance and timing data revealed the iNPUT-ACE Camera Match Overlay tool was an effective method for analyzing vehicle speed across a variety of video sources.