Citation

Starr RA, Sandberg WH, Guan Y. ITE J. 2004; 74(8): 32-42.

Affiliation

Minnesota Dept. of Transportation, ITE, Minneapolis, MN, United States

Copyright

(Copyright © 2004, Institute of Transportation Engineers)

DOI

unavailable

PMID

unavailable

Abstract

The Minnesota DOT received a complaint from a color-blind person that, under direct sunlight reflection, he could not tell whether the red or green LED indication was on. To investigate the issue, Washington County installed several different LED signal head designs on Valley Creek Road. To understand the problem and better serve the general traveling public, an internal study on color-blind vision issues related to LED traffic signal indications was initiated. Eight volunteers observed two signals at each of seven intersections, for a total of 112 observations. Analysis of the data confirmed that people with red-green color blindness could perceive some common LED green signals erroneously during direct sunlight conditions. Color-blind and non-color-blind travelers perceived LED green indications differently.

Language: en