VISUAL AIMING OF EUROPEAN AND U.S. LOW-BEAM HEADLAMPS

This study evaluated the effect of the sharpness of the cutoff (the transition between the lighter and darker portions of the beam) of low-beam headlamps on visual vertical aiming. Out of ten lamps tested, seven had a U.S. type beam pattern and three had a European type beam pattern. Twenty younger and middle-aged subjects of both sexes, along with an experienced lamp aimer, were asked to adjust the aim of the lamps in such a way that the cutoff of the beam was coincident with a horizontal line on a vertical surface. The subjects were instructed to make the alignment using the illumination gradient to the right of vertical for the U.S. type lamps and to the left of vertical for the European type lamps. Each person aimed each lamp ten times. There were two main results. First, the location of the perceived cutoff was near the location of the maximum contrast between adjacent vertical parts of the beam pattern. Second, the variability of the aiming performance was systematically related to the magnitude of the maximum contrast.

  • Corporate Authors:

    University of Michigan Transportation Research Institute

    2901 Baxter Road
    Ann Arbor, MI  United States  48109-2150
  • Authors:
    • Sivak, M
    • FLANNAGAN, M
    • Chandra, D
    • GELLATLY, A W
  • Publication Date: 1991-11

Media Info

  • Pagination: 30 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00619067
  • Record Type: Publication
  • Report/Paper Numbers: UMTRI-91-34, HS-041 441
  • Files: HSL, TRIS
  • Created Date: Feb 29 1992 12:00AM