Role of adaptation in perception under traffic lighting conditions.

Drivers at night need to detect and perceive visual information for safe driving under artificial lighting conditions, either with vehicle headlights or fixed lighting installed along the road. It has been pointed out that to make the necessary visual illumination perceptible under non-uniform luminance background conditions, as under artificial lighting conditions, the influences of adaptation luminance and background luminance on the luminance difference threshold have to be dealt with independently and separately. On the basis of experiment results concerning these influences, the role of adaptation luminance in the total luminance difference was examined. For the covering abstract see ITRD E123380.