Video-based monitoring of pedestrian movements at signalized intersections

Pedestrian and cyclist crossing characteristics are important for the design of urban intersections and signalized crossings. Parameters such as waiting time, crossing time, and arrival rate are key variables for describing pedestrian characteristics and improving crossing designs and signal timing plans. Manually collecting such data is often extremely labor intensive. Therefore, an automated computer-vision-based approach is introduced for collecting these parameters in real time with ordinary video cameras. Broadly defined pedestrian objects, including bicyclists and other nonmotorized modes, are extracted by means of the background subtraction technique and tracked through an inherent cost characteristic function in conjunction with an α-β-fllter. The waiting-zone concept introduced helps provide robust pedestrian tracking initialization and parameter extraction. The proposed approach is implemented in a pedestrian tracking (PedTrack) system by using Microsoft Visual C + +. Tested with real video data from three study sites, this system was proved to be effective and about 80% of pedestrian crossing events were successfully detected. PedTrack shows the potential to be a great data collection tool for nonmotorized object movements at intersections.