Citation

Motoki M, Hashimoto H, Hirao T. Proc. Int. Tech. Conf. Enhanced Safety Vehicles 2009; 2009.

Copyright

(Copyright © 2009, In public domain, Publisher National Highway Traffic Safety Administration)

DOI

unavailable

PMID

unavailable

Abstract

When a motorcycle is driven on a curved road, the motorcycle headlamp inclines horizontally as the motorcycle body banks, and the area illuminated by the headlamp becomes limited. Therefore, minimizing the horizontal inclination of the headlamp would improve the visibility. This study was conducted to clarify the effects of a system to adjust the horizontal inclination of the motorcycle headlamp (hereafter, "motorcycle AFS") on visibility for the rider, and to examine the side-effects of the motorcycle AFS (e.g., discomfort glare for oncoming drivers). The study included the following two parts: (1) A simulation survey and an actual driving survey to test the visibility demonstrated that a motorcycle AFS enhances visibility for the rider while the motorcycle is being driven on a curved road. When the horizontal inclination of the headlamp is adjusted by the same or greater amount than the bank angle of the motorcycle body, the visibility evaluation scores are equal to or above the just acceptable level. However, when the adjustment amount is less than the bank angle, the visibility evaluation scores are below the just acceptable level. (2) A simulation survey and an actual driving survey to evaluate the discomfort glare showed that when the horizontal inclination of the headlamp is adjusted by the same or smaller amount than the bank angle, the glare evaluation scores are equal to or above the just acceptable level. However, when the adjustment amount is more than the bank angle, the glare evaluation scores are below the just acceptable level. Based on the results obtained in this study, the following technical requirement is proposed for the motorcycle AFS: A horizontal inclination adjustment system (HIAS) may be installed. However, the adjustment amount of horizontal inclination shall not exceed the vehicle's bank angle. The full text of this paper may be found at: http://www-nrd.nhtsa.dot.gov/pdf/esv/esv21/09-0385.pdf