PURPOSE: To detect the state of the road surface by detecting the reflected received microwave level of the microwave projected against the road surface with predetermined output and the radiating temperature of the road surface.
CONSTITUTION: A cantilever B is extended from the end of a post P, and there are provided a road surface infrared radiation thermometer 1, a microwave transmitter 2, a microwave receiver 3 so mounted that the detecting direction of the respective detectors is directed toward the measuring range A. A signal processor 5 is installed at the side of the road, and a supersonic vehicle sensor 4 is similarly installed at the cantilever B. The signals from the respective detectors are processed by the signal processor 5 to detect the state of the road surface and particularly the frozen state thereof.
TSUJII KOUICHI
ITAI YASUO
HINOKIBAYASHI KOUICHI
