MEASUREMENT AND VERIFICATION OF THE RESIDUAL SALT ON THE ROAD SURFACE USING A VEHICLE-MOUNTED SALINITY SENSOR

Abstract

 Antifreezeing agent is sprayed based on the road surface temperature and the salinity of the water on the road surface. In order to judge the risk of slip accidents and the amount of spraying antifreezeing agent, the thickness of water film and the amount of residual salt on the road surface are also required.

 In order to devlope a sensor for measuring the thickness of water film on the road surface that enables continuous measurement while driving, we have improved the device that measures salinity on the road surface by water splashed from the vehicle's tires. In this paper, we verified the measurement accuracy of device for the thickness of water film, the water salinity and the residual salt on the road surface throught driving tests. Moreover, we clarified the characteristics and points for improvement of the device. The following are the findings. (1) At a passage speed of 20 km/h, the measurement accuracy deteriorated because the water splashed by the tire was too small compared to the water supplied from inside the vehicle to the salinity sensor. (2) The measurement accuracy deteriorated that the salinity on the road surface is closer to the salinity of the supplied water. (3) The device was found to measure the residual salt on the road surface with error of 3.1 g/m², in case of the salinty of the water on the road is less than 8%.