Collecting detailed traffic information such as velocity of vehicles, size of vehicles and rate of road occupancy is necessary to efficiently control traffic on general roads. In Japan, ultrasonic sensors, microwave sensors and image sensors are widely used for the above purpose. Especially microwave sensors and image sensors are used to know the velocity of vehicles, but they have some errors in counting the number of vehicles. The authors have developed a velocity measuring vehicle sensor with modulated light wave range detection technique to improve the accuracy of counting the number of vehicles and have got good results in field tests on an actual road. In this paper they report an outline of the newly developed sensor and the results of its field test.
Abstract