MEASUREMENT SYSTEM AND METHOD FOR REFLECTION PROPERTIES OF WET ROAD SURFACES (OP40, 294-302)

This paper describes the measurement methodology and system architection of reflection properties of wet road surfaces in the description form of r-table as defined by CIE 66-1984. The aim of the measurement is to improve the accuracy of luminance simulation in the application of outdoor road lighting, specificly for the raining condition. A segmented measurement process was defined and applied in the measurement, which successfully solved the issue of rapid attenuation of 'wetness' on the road surface that was measured. A new parameter, namely 'drying time' is introduced to better reflect the dynamic change of reflection properties during and after the rain. The series of wet r-table with 'drying time' as classified label would be considered as practical design basis for optimizing the lighting solutions for the raining condition.