Vendor Comparison of Video Detection Systems

Abstract

Video detection has become increasingly popular for presence detection at signalized intersections because of its versatility. However, several reports have documented performance problems in specific systems. This paper quantifies the performance of three different commercially available video detection systems. The systems were tested in May and September 2005 for presence detection accuracy. Prior to the May 2005 test, a representative from each vendor configured the video detection zones to match the loop detection zone as closely as possible. The outputs from the loop detection for the through-right and left-turn lane groups were compared with the corresponding output from each of the video detection systems. Whenever there was a discrepancy between the loop and video, a digital video was observed to determine the cause of the discrepancy. Missed calls and false calls were categorized for each system. The errors were also categorized according to the impact that they would have on signal operations. During a 24hr test on two separate days, the number of missed detections longer than 5 seconds ranged from 9 to 147, and the number of false calls longer than 5 seconds ranged from 16 to 149.