FACTORS IN VISIBILITY AND LEGIBILITY OF HIGHWAY SIGNS AND MARKINGS

THE VISIBILITY OF HIGHWAY SIGNS AND SOME OF THE PRINCIPLES THAT HAVE BEEN DEVELOPED OVER THE YEARS WITH RESPECT TO STROKE WIDTH, VISUAL ANGLE, CONTRAST, COLOR OF THE BACK- GROUND, AND THE RELATIVE MERITS OF LIGHT CHARACTERS ON DARK BACKGROUND AND DARK CHARACTERS ON A LIGHT BACKGROUND ARE DISCUSSED. WE CAN SEE A LETTER AT A DISTANCE OF ABOUT 55 FEET PER INCH OF LETTER HEIGHT IN DAYTIME, 33 FEET PER INCH AT NIGHT. THESE VALUES ARE FOR A PERSON WITH 20/20 VISION. SOMEONE WITH 20/40 VISION, THE USUAL CUT-OFF FOR A REGULAR DRIVER'S LICENSE, MUST BE APPROXIMATELY HALF AS FAR FROM A GIVEN LETTER IN ORDER TO SEE IT CLEARLY. EXPERIMENTAL WORK THAT FORBES HAS DONE USING NONSENSE SYLLABLES AND RANDOM SEQUENCES OF LETTERS YIELDS QUITE DIFFERENT RESULTS THAN WORK DONE WITH FAMILIAR WORDS. FAMILIAR WORDS CAN BE DETECTED AT A MUCH GREATER DISTANCE. /AUTHOR/

• Supplemental Notes:
  • pp 12-29, 8 FIG, REF
• Corporate Authors:

  National Academy Sciences

  /Committee On Vision
  ,   United States 
• Authors:
  • Forbes, T W
• Publication Date: 1969

Subject/Index Terms

• TRT Terms: Contrast; Height; Legibility; Road markings; Spacing; Traffic signs; Visibility; Width
• Old TRIS Terms: Backgrounds; Traffic marking
• Subject Areas: Highways; Safety and Human Factors;

Filing Info

• Accession Number: 00221324
• Record Type: Publication
• Files: TRIS
• Created Date: Jul 2 1971 12:00AM