Visibility under night driving conditions. Part 3. Derivation of (delta L.A.) characteristics and factors in their application.

For unlit, open road conditions it has been shown that the visibilities of tail lights, disc objects and pedestrian dummies can be related by a single luminance- visual area characteristic. A set of luminance increment- visual area (delta L.A.) night driving characteristics has been established for predicting visibility under varying conditions of background and glare veiling luminances. A number of topics are discussed with regard to the derivation and application of the proposed (delta L.A.) night driving characteristics.