A Spatial Image Processing Traffic Flow Sensor and it's applications for Signal Control, Surveillance and Warning System

In this paper, the authors describe a spatial image processing traffic flow sensor which can measure a wide range of traffic flow information such as volume, speed, vehicle type, vehicle presence, and traffic congestion length. The sensor can also detect illegally parked vehicles and abnormal traffic conditions. The authors describe how the sensor has been applied to traffic signal control and an image surveillance system. They also discuss a collision avoidance warning system for use in tunnels. The system provides the most useful queue length measurement results to a variable message board.