LETTER AND SIGN CONTRAST, BRIGHTNESS, AND SIZE EFFECTS ON VISIBILITY

EXPERIMENTAL RESULTS ARE PRESENTED ON SIGN SIZE AND BRIGHTNESS AND LETTER-TO-SIGN BRIGHTNESS RATIO. THIS SERIES OF EXPERIMENTS WAS CONDUCTED TO MEASURE: (1) THE EFFECTS OF SIGN SIZE, BRIGHTNESS, AND LETTER-TO-SIGN BRIGHTNESS RATIO, AND (2) THE EFFECTS OF COMPETING SIGNS ON HIGHWAY SIGN VISIBILITY. A TYPICAL HIGHWAY SCENE FOR DAY OR NIGHT CONDITIONS WAS PROJECTED CONTINUOUSLY ON THE SCREEN IN FRONT OF THE SUBJECT. FROM TIME TO TIME UNDER AUTOMATIC CONTROL, KEYED BY ITS OWN RESPONSES TO AN AUXILIARY TASK, FOUR SIMULATED INTERSTATE GREEN HIGHWAY SIGNS WERE FLASHED ON THE SCREEN SUPERPOSED ON THE PREVIOUS HIGHWAY SCENE. IT WAS DETERMINED THAT THE EXPECTED ADVANTAGE FOR THE LARGEST OF FOUR SIGNS WAS FOUND CONSISTENTLY WHEN THE SIMULATED GREEN SIGNS WERE SEEN AGAINST EITHER DAY-SNOW OR THE NIGHT BACKGROUND. IT WAS DETERMINED THAT AN ADVANTAGE FOR VISIBILITY WAS ENHANCED BY A COMBINATION OF: (1) GREATER SIGN BRIGHTNESS, (2) GREATER RELATIVE SIGN SIZE, (3) CONTRAST OF SIGN AGAINST BACKGROUND, AND (4) LETTER-TO-SIGN BRIGHTNESS. FINDINGS SUGGEST THAT SILHOUETTE SEEING IS OF IMPORTANCE FOR VISIBILITY OR ATTENTION VALUE WHERE SIGNS ARE SEEN AGAINST A BRIGHT BACKGROUND. OPTIMUM COMBINATIONS OF THESE VARIABLES MUST BE FOUND TO OBTAIN BEST ATTENTION VALUE AND BEST LEGIBILITY.

• Record URL:
  • http://onlinepubs.trb.org/Onlinepubs/hrr/1968/216/216-005.pdf
• Supplemental Notes:
  • Paper sponsored by Committee on Night Visibility. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved.
• Authors:
  • Forbes, T W
  • Fry Jr, J P
  • Joyce, R P
  • Pain, R F
• Publication Date: 1968

Media Info

• Media Type: Digital/other
• Features: Figures; References;
• Pagination: pp 48-54
• Monograph Title: Lighting, visibility and driving
• Serial:
  • Highway Research Record
  • Issue Number: 216
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Brightness; Contrast; Daylight; Interstate highways; Legibility; Lettering; Motion pictures; Night; Signs; Simulation; Size; Snow; Traffic signs; Visibility
• Old TRIS Terms: Letters
• Subject Areas: Highways; Safety and Human Factors;

Filing Info

• Accession Number: 00220135
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Jul 29 1994 12:00AM