This paper describes a sideward-radiation-type optical vehicle sensor, developed in Japan, details some methods for testing it experimentally, presents the results of the tests, and indicates some possible improvements. The sensor has a sensing unit, communication unit, and transmitter-receiver. It is designed to detect vehicles on a multi-lane road, and enable two-way communication with vehicles with on-board transmitter-receivers. Its light projectors and receiver are installed above the road's first lane. The following stand-alone field performance tests were conducted, to confirm the sensor's communication functions: (1) communication function test: static characteristics; characteristics; (2) communication function test: dynamic characteristics; (3) parallel-advance communication function test; (4) communication allowance test; and (5) special environmental test of the effect of rain. Satisfactory results were obtained in the first four tests. The system could be improved by miniaturising both the main sensor equipment, above the road, and the on-vehicle equipment.
Abstract