The effectiveness of daytime running headlamps in Japan was investigated. Experimental tests of car and motorcycle visibility were conducted at dusk and an equation to estimate car visibility was proposed on the basis of the results. Further trials considered the effect of vehicle body brightness and the choice of light or dark colours. Separate equations were developed for the brightness of light and dark cars. With both cars and motorcycles there was an obvious increase in visibility with daytime running lights on compared with off, especially under poor lighting conditions. For the covering abstract see ITRD E123380.
Abstract