Blue Content of LED Headlamps and Discomfort Glare

This study evaluated the effect of blue content of headlamps on discomfort glare, in order to provide guidance regarding spectral compositions that would minimize driver complaints. Three LED headlamps were tested (with correlated color temperatures of 4000, 4800, and 6600 K), as well as a tungsten-halogen headlamp and a HID headlamp. Subjects, seated in a stationary vehicle, rated discomfort from brief presentations of stimuli that produced illuminances of 0.25, 0.5, and 1 lux. As predicted in a previous analytical study, it was found that, when they appear bluer than current tungsten-halogen or HID headlamps, LED headlamps tend to produce more discomfort glare. The effect is probably due to the color appearance of the LED lamps used in this study rather than to any inherent characteristic of LED sources, and it could probably be altered or reversed with different sources. For the data reported here, ratings of discomfort glare were linearly related to the amount of blue content in the light output as weighted by the spectral sensitivity of the short-wavelength (blue) cone photoreceptors. Therefore, if this relationship is replicated and extended in future studies, it may provide an index of blue content that could be used heuristically to select colors of headlamps to minimize driver complaints about glare.

• Supplemental Notes:
  • This research was sponsored by the University of Michigan Industry Affiliation Program for Human Factors in Transportation Safety.
• Corporate Authors:

  University of Michigan Transportation Research Institute

  2901 Baxter Road
  Ann Arbor, MI  United States  48109-2150
• Authors:
  • Sivak, Michael
  • Schoettle, Brandon
  • Minoda, Takako
  • Flannagan, Michael J
• Publication Date: 2005-2

Language

• English

Media Info

• Media Type: Print
• Features: Appendices; Figures; References; Tables;
• Pagination: 21p

Subject/Index Terms

• TRT Terms: Blue; Glare; Headlamps; Light emitting diodes; Luminous intensity
• Uncontrolled Terms: High intensity discharge headlamps; Tungsten-halogen lamps
• Subject Areas: Highways; Safety and Human Factors; Vehicles and Equipment; I91: Vehicle Design and Safety;

Filing Info

• Accession Number: 01000733
• Record Type: Publication
• Source Agency: National Highway Traffic Safety Administration
• Report/Paper Numbers: UMTRI-2005-2
• Files: HSL, TRIS, USDOT
• Created Date: Jun 6 2005 2:33PM