A BRIGHTNESS INVENTORY OF CONTEMPORARY SIGNING MATERIALS FOR GUIDE SIGNS, WITH DISCUSSION AND CLOSURE

THE PURPOSE OF THIS STUDY IS TO MEASURE THE BRIGHTNESS OF CONTEMPORARY SIGN MATERIALS IN ACTUAL USE SITUATIONS, AS OBSERVED BY THE DRIVER UNDER NORMAL DAYTIME AND NIGHTIME VIEWING CONDITIONS. DETERMINATIONS WERE MADE FOR 7 APPROACH DISTANCES FOR HIGH AND LOW BEAMS AT NIGHT AND FOR 2 DISTANCES BY DAY. LUMINANCE READINGS WERE OBTAINED FOR 4 LEGEND MATERIALS, 3 BACKGROUND MATERIALS, AND 18 ENVIRONMENTAL CONDITIONS. RESULTS INDICATE THAT LUMINANCES FOR SIGN LEGENDS OF OVER 1 FOOT-LAMBERT ARE AVAILABLE ON LOW BEAMS FOR ENCAPSULATED LENS AND BUTTON REFLECTIVE MATERIALS ON UNLIGHTED OVERHEAD SIGNS FOR THE LEGIBILITY DISTANCES AVAILABLE. THREE LEGEND MATERIALS ARE IN EXCESS OF THIS LEVEL FOR THE SHOULDER-MOUNTED LOCATION ON LOW BEAMS. THIS LUMINANCE LEVEL HAS BEEN SUGGESTED BY EARLIER INVESTIGATORS AS THE MINIMUM LEVEL FOR ADEQUATE LEGIBILITY. WITH HIGH BEAMS, LUMINANCES OF 10 TO 20 FOOT-LAMBERTS , EQUIVALENT TO THOSE EXHIBITED FOR ILLUMINATED OVERHEADS, ARE AVAILABLE FOR SEVERAL MATERIALS ON BOTH OVERHEAD AND SHOULDER-MOUNTED SIGNS. MAXIMUM REFLECTIVE SIGN LUMINANCE OCCURS AT DISTANCES SIMILAR TO THE MAXIMUM LEGIBILITY DISTANCES FOR THE LETTER SIZES EMPLOYED ON INTERSTATE GUIDE SIGNS, A CIRCUMSTANCE OF THE HEAD-LAMP DISTRIBUTION PATTERN, SIGN OFFSET, MATERIAL EFFICIENCY, AND THE LETTER SIZES COMMONLY ENCOUNTERED. /AUTHOR/

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/hrr/1971/377/377-007.pdf
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/0309019923
• Supplemental Notes:
  • Sponsored by Committee on Visibility and presented at the 50th Annual Meeting. 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:
  • Youngblood, W P
  • WOLTMAN, H L
  • Straub, A L
  • Allen, T M
• Publication Date: 1971

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: p. 69-91
• Monograph Title: Visibility
• Serial:
  • Highway Research Record
  • Issue Number: 377
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Field studies; Legibility; Materials; Photometers; Retroreflection; Signs; Traffic signs; Visibility
• Old TRIS Terms: Retrodirective reflection; Traffic sign materials
• Subject Areas: Highways; Materials; Safety and Human Factors;

Filing Info

• Accession Number: 00221660
• Record Type: Publication
• ISBN: 0309019923
• Report/Paper Numbers: HS-011 999
• Files: TRIS, TRB
• Created Date: May 22 1972 12:00AM