DETECTION AND IDENTIFICATION OF LED TRAFFIC SIGNALS BY PROTAN OBSERVERS

Protan (red color blind) observers have lower spectral sensitivity than color normal observers at long wavelengths of the visible spectrum. Responses of protan and color normal subjects to light emitting diode (LED) and incandescent traffic signals of red and yellow nominal color during simulated daytime viewing conditions are described. Reaction times, missed signal percentages and color identification accuracy were measured. The results indicate that for protans, detection performance to red LED signals was enhanced when the dominant wavelength was moved toward shorter wavelengths, but this shift also appeared to decrease their ability to correctly identify the signal color. Although the yellow LED signal used in this study provided similar detection performance for protans as a yellow incandescent signal, its dominant wavelength was sufficiently long for it to sometimes be confused with red. In general, the results of this study are consistent with the 1994 recommendations of the Commission Internationale de l'Iclairage for signal colors to be seen by color normal and protan observers. Nonetheless, neither detection nor color identification for protans approached that of color normal observers

• Supplemental Notes:
  • Publication Date: 2003. Transportation Research Board, Washington DC. Remarks: Paper prepared for presentation at the 82nd annual meeting of the Transportation Research Board, Washington, D.C., January 2003. Format: CD ROM
• Corporate Authors:

  University of California, Berkeley

  California PATH Program, Institute of Transportation Studies
  Richmond Field Station, 1357 South 46th Street
  Richmond, CA  United States  94804-4648

  California Department of Transportation

  1120 N Street
  Sacramento, CA  United States  95814

  University of California, Berkeley

  Department of Electrical Engineering and Computer Sciences
  Berkeley, CA  United States  94720
• Authors:
  • Huang, Michelle Kun
  • Bullough, John D
  • Boyce, Peter R
  • Bierman, Andrew
• Conference:
  • Transportation Research Board 82nd Annual Meeting
  • Location: Washington DC, United States
  • Date: 2003-1-12 to 2003-1-16
• Date: 2003

Language

• English

Media Info

• Pagination: 18 p.

Subject/Index Terms

• TRT Terms: Human factors; Light emitting diodes; Traffic signals
• Subject Areas: Safety and Human Factors; Society;

Filing Info

• Accession Number: 00938823
• Record Type: Publication
• Source Agency: UC Berkeley Transportation Library
• Files: PATH, STATEDOT
• Created Date: Mar 3 2003 12:00AM