TRAFFIC SIGNAL LUMINANCE AND VISUAL DISCOMFORT AT NIGHT
Document Type
Journal Article
Publication Date
2001
Subject Area
operations - traffic, infrastructure - traffic signals, mode - bike
Keywords
Yellow interval (Traffic signal cycle), Traffic signals, Traffic lights, Traffic control signals, Specifications, Red interval (Traffic signal cycle), Night vision, Luminous intensity, Luminance, Light emitting diodes, LEDs, Human comfort, Highway traffic signals, Green interval (Traffic signal cycle), Comfort, Amber phase
Abstract
The visual discomfort from simulated traffic signals under nighttime viewing conditions was assessed. Discomfort increased with increasing signal luminance and decreasing viewing distance. Color identification of signals was very high for all signal colors and luminances studied. Red signals meeting luminous intensity specifications of the Institute of Transportation Engineers (ITE) and specifications being drafted in Europe were unlikely to cause visual discomfort under the conditions tested. Green and yellow signals meeting ITE and European specifications were more likely to cause visual discomfort. Dimming signals using light-emitting diodes might be a feasible strategy for minimizing discomfort under some nighttime viewing conditions.
Recommended Citation
Bullough, J, Boyce, P, Bierman, A, Hunter, C, Conway, K, Nakata, A, Figueiro, M. (2001). TRAFFIC SIGNAL LUMINANCE AND VISUAL DISCOMFORT AT NIGHT. Transportation Research Record, Vol. 1754, p. 42-47.
