AUTOMATIC VEHICLE QUEUE MEASUREMENT AT INTERSECTIONS USING IMAGE-PROCESSING

This paper describes a system for measuring queue length at intersections in real time by means of video sensors. The requirements and constraints of such a system are discussed. The system devloped and its operation are described. It is based on a closed circuit television, black and white camera and PC (486DX2) with a digitalisation board for each link forming the junction. Four stages are described: a) information compression, b) pattern detection, c) disturbance removal and d) queue length computation. A trial of the system is described and the results presented. Some problems were experienced at night time and with shadows but otherwise the results proved satisfactory. For the covering abstract see IRRD 880251.