System for optically detecting vehicles traveling along the lanes of a road

摘要

A system for optically detecting vehicles traveling a road having a plurality lanes. The system includes a gantry provided at the road so as to straddle the plurality lanes. There are a plurality of optical line sensors provided on the gantry, for obtaining linear images of a surface of the road. There are optical line sensors arranged in two rows and in a staggered pattern such that each has a view field overlapping the view field of either adjacent optical line sensor by the sum of half the view field and a width of a motor cycle, photoelectric sensor apparatus consisting of photo-projector elements and photo-detector elements and optical axes which are parallel to each other and are substantially located in the position of the view field of the optical line sensors. There is a signal-processing section for detecting a vehicle traveling under the gantry in accordance with output signals of the optical line sensors and output signals of the photoelectric sensor apparatus, by using reference signals which the optical line sensors generate when no vehicles travel under them.