Effects of sweeping, color and luminance distribution on response to automotive stop lamps

  • Published: Society of Automotive Engineers, Inc. (SAE); SAE 2002 World Congress: Detroit Michigan, U.S.A., 4-7 March 2002
  • Authors: Bullough J D, Yan H, Van Derlofske J
  • Date Added: 25 Jan 2014
  • Last Update: 25 Jan 2014
  • Format: html


Quantifying the relative impact of colour and luminance distribution on visual response of stop lamps.


A total of 24 adults between the ages of 23 and 60 years participated as subjects. During the experiment, subjects continuously performed a task tracking arrays of red and yellow LEDs whilst holding down a small switch on the control box. When they detected the onset of the brake light in their peripheral vision, they were instructed to release the switch as quickly as possible, and then to re-press the switch.

Key Findings:

  • The data presented here add to the possibility that the luminance distribution of a high-mounted central brake light is an important factor in the resulting visual response. Even though the neon and the LED had similar dominant wavelengths and provided nearly the same luminous intensity, reaction times to the neon light were consistently and significantly longer than to the LED.

  • It appears that an array of small point sources can be more effective than an equivalent (here, equivalence is defined in terms of luminous intensity in the forward direction) diffuse source at eliciting rapid visual responses.


Colour and luminance, automotive stop lamps, brake lights


Building on previous research by these authors and others.