VISUALLY CRITICAL ELEMENTS IN NIGHT DRIVING, IN RELATION TO PUBLIC LIGHTING

This presentation focuses upon car driving at night outside built-up areas. In order to apply public lighting selectively and efficiently it is necessary to know which elements in the task environment of a car driver are insufficiently visible for safe and smooth driving, using (dipped) vehicle lighting. The visibility of these "visually critical elements" is amenable to improvement, in particular by public lighting. Until now, the visibility of the so-called "critical object" (something like a brick at 100 m distance on the road surface) has been used as an important criterion for the quality of public lighting. However, the relation between seeing such an object and traffic safety is not very clear. The results of two exploratory studies on the nature of visually critical elements are briefly presented.