This study was conducted to clarify the effects of automatic headlamp on (AHO) and position lamps on improving the conspicuity of two-wheeled vehicles in the daytime and at dawn/dusk. The following two items were covered:
Effect of AHO on reducing injury-causing accidents
The data was taken from 1990 to 2001 on traffic accidents in Japan involving two-wheeled vehicles. Specific accident configurations closely associated with the conspicuity of two-wheeled vehicles (collision while turning right, right-angle collision, head-on collision) were selected and analyzed.
The findings are as follows:
AHO was confirmed to be effective in reducing the number of specific accidents closely associated with the conspicuity of two-wheeled vehicles in the daytime and at dawn/dusk. As the percentage of AHO-equipped vehicles in the total number of two-wheeled vehicles rose from 0% in 1990 to 71% in 2001, it was calculated that AHO's reduction of specific accidents in the daytime and at dawn/dusk amounted to 12,124 cases (16.0%).
Effect of AHO and position lamps on improving two-wheeled vehicle conspicuity
Twelve subjects observed the approach of an oncoming motorcycle followed by a passenger car (30 m behind) with its passing beams on. Instructions were given to indicate the motorcycle’s conspicuity when it arrived at a point 100 m ahead of their eyepoint.
Eight motorcycle lighting conditions were observed.
The findings are as follows.
AHO has an improvement effect on two-wheeled vehicle conspicuity in the daytime and at dawn/dusk. To further improve the conspicuity, it is effective to combine amber position lamps with AHO. The effect of position lamps can be increased by optimizing their color, luminous intensity and distance from the headlamp.