The Dutch Ministry of Public Works and Water Management intends to provide differentiation in public lighting intensity on motorways, so that dependent on the traffic situation optimal lighting levels are provided. The level of lighting is changed dynamically on the basis of ambient light level, traffic intensity and weather conditions. Dynamic road lighting will be installed on a presently unlit section of the A12 motorway. The aim is to determine the dynamic road lighting effects. In this report the visually critical elements in the highway scene during darkness are listed. A description of the test road section results in a selection of visually critical elements that are important to this specific road section. It is concluded that, partially dependent on traffic intensity, especially the road course, lane borders and behaviour of other road users are relevant. Low-intensity public lighting (0.2 cd/m2) seems sufficient under optimal circumstances. Public lighting of minimally normal intensity (1.0 cd/m2) is likely to be beneficial in case of limited sight distances and average or high traffic intensities. (A)
Abstract