Concrete Roads and Road Lighting Design

Knowledge about pavement reflection properties is needed in order to design a road lighting installation. CIE (International Commission on Illumination) has created a method for describing the reflection properties of a dry surface in terms of the pavement brightness and degree of specularity. From here, CIE has created a classification system for dry surfaces. A similar classification system also exists for wet surfaces, but this is not as well developed as the one for dry road surfaces. There is a great demand of updating these values by new measurements, particularly for concrete, in order to determine the value of brightness and specularity. Performed calculations show that the pavement brightness has a considerable impact on the road lighting design for dry surfaces and that advantages hold for higher values. Field measurements of the brightness and retroreflection of concrete roads in Sweden have been carried out at CBI. The measurements include both dry and wet road surfaces with different surface structures. The results from these tests will be analysed in order to try to determine the relationship between brightness, specularity and texture. From here recommendations will be given regarding classification of concrete pavements in road lighting design.