EXTENSION OF THE LUMINANCE CONCEPT IN ROAD AND TUNNEL LIGHTING

摘要

The visual impression of the luminance distribution of the road surface in front of a vehicle driver does not correspond necessarily well with the determined values of the lighting criteria obtained for the traditional angle of observation. To overcome these discrepancies it is proposed to extend the current luminance concept and to apply an additional angle of observation. This requires the knowledge of the reflection characteristics of the pavements for different angles of observation. For the determination of the expected uniformities at the design stage it is necessary to use a calculation grid which is about three times denser than the usual grid. The assumption of a different angle of observation has also a decent impact on the estimated veiling luminances and the resulting threshold increments in road and tunnel lighting.