Abstract
The purpose of this study is to investigate an influence of the brightness distribution of the road surface on recognition of an object on the road. By modeling light distribution of low beam on CRT display by a computer, we examined a visibility of the target on the brightness of background as the light distribution model. The target horizontally runs reciprocating motion, its luminance decreases step-wise and also the luminance contrast between background and target. If the target is visible, the subject can gaze the moving target, if it is invisible the subject can not gaze. We measured the luminance contrast threshold of the target by using the so-called moving target method. As the results, we found out that driver's discomfort feelings were increased and the target visibilities were reduced, on the case of the excessive road surface brightness.
