Road Surface Wetness Variations: Measurements and Effects for Winter Road Maintenance

Abstract

Road wetness is a critical parameter when it comes to preventing road slipperiness. It has so far been difficult to measure, but new measurement techniques on the market make it useful to investigate the savings opportunities within road maintenance operations. The present study tests a new sensor mounted on a road maintenance vehicle run in a maintenance district in central Sweden. The sensor that measures road surface water depth is connected to a global positioning system (GPS) system and a global system for mobile communications (GSM) phone modem. Potential savings are calculated based on the measured road surface water depth and on the amount of applied salt needed to lower the freezing point to a certain degree. The results indicate variations in water depth along the measured roads, which implies that the salt concentrations along the roads could also vary. Though the variations were smaller along the tested highway, the calculated savings could still be up to 22%. Despite the many assumptions made in the calculations, considerable savings could potentially be realized by applying such wetness measurements.