System for Measuring Splash on Wet Pavements

Vehicles traveling on wet pavements produce splash and spray that reduce driver comfort and safety. The amount of water thrown up by a vehicle's tires depends on many factors such as the type of vehicle and the speed at which it is traveling, the weather conditions, and the pavement surface. Drainage wearing courses and rough macrotexture pavements reduce or completely suppress splash and spray. Nonetheless, the effect of pavement type on splash and spray has yet to be fully elucidated, and there is a need for simple systems that can provide rapid measurements of this phenomenon on real roads. Tests are described with a prototype for a new system consisting of a laser unit and a high-resolution camera that measures splash and shows the effect of pavement surface on the amount of splash produced. Unlike existing systems, which evaluate a single, often nonrepresentative stretch of pavement, the system described can provide continuous measurements over stretches of road. Moreover, the measurement process is sensitive to both water flow and tire speed, and the results analyzed confirm the repeatability of the system and its sensitivity to pavement texture.