It has been generally accepted that road lighting design should be based on the luminance concept. This requires a.o. data on the light distribution of the luminaires (the I-table) and the reflection characteristics of the road surface to be used (the R-table). Applying the recently introduced two-class mad surface classification system (C-system) the relevant R-table can be selected if only three refection values known. The device described here allows the measurement in situ of P (0;0) (or qp); P (2;0) and P (1;90) on the actual road surface, during the daytime and without undue disturbance of the traffic on the road.
Abstract