The purpose of the running light (rl) is to mark the vehicle so that it is easier for other road users to see its position and motion, and to identify it. A light source whose main purpose is to improve the driver's visibility, is not a rl according to this definition. A fixed rl is a light that is on as long as the motor is running, or as long as the vehicle is in motion. Such a light might be put into operation by means of the ignition switch. Observations in the traffic of oslo have confirmed the fact that the use of rl today is very non-uniform. In the interest of the traffic safety something should be done to obtain better uniformity. This problem might be solved by allowing only one type of light source to be used, and by introducing technical arrangements which make the use of the rl less dependent on the driver. Possible rl-sources for cars have been studied. All things considered, lowbeam headlights seem to be the best choice today. It is concluded that the intensity of the low beam headlight must be reduced when driving in lighted streets to keep the discomfort glare to an acceptable level. This reduction factor for the european asymetric lowbeams is found to lie in the region 1/4 to 1/6. During daytime one can choose between full and reduced intensity of the lowbeam headlight. In most cases the reduced intensity should be sufficient, but in some cases of very low visibility, i.e. dense fog, full intensity is preferable. If the use of rl is to be more independent of the driver, and if the rl is to be used only in those cases in which it is used today, a satisfactory solution will require the use of fairly advanced automatic equipment. Fixed rl is also discussed from the point of view of the pedestrian and the cyclist. It is concluded that fixed rl will be advantageous also for these groups. See also B 17169.
Abstract