2. Tracking traveling trajectory The traveling trajectory of eachvehicle is evaluatedfrom the analog images of 30 frames/sec.The computation of a traveling trajectory is mainly divided into two steps. The first stepis vehicle detection and the temporal median filter is usedto update a background image adaptively as shown in Figure I. In this pape1; we introduce a system that detects all kinds of violations at a street intersection such as red light running, speed violation, stop line violation and lane violation by tracking individual vehicles. Two cameras are used for detecting vioJ'ations. One is an analog camera for real-time tracking and the other is a digital camera for license plate reading. This system is connected to the traffic signal system controller and monitors the red, arro»; yellow and green phases of an approach. Two loops in the road are used to detect vehicle approach and speed. The system takes pictures of all vehicles passing a second loop and tracks the vehi...