OVERHEAD SIGNS WITHOUT EXTERNAL ILLUMINATION

The basic objective of this research was the evaluation of high-intensity reflective sheeting for use on overhead sign installations without external illumination. The effects of height above the roadway and angle of sign tilt with respect to the vertical, headlight configuration, and vehicle approach speed to sign legibility distance were measured for both an externally illuminated sign and a high-intensity reflective sheeting sign. It was concluded that the nighttime legibility distance of overhead signs was not appreciably affected by increases in mounting height in the range of 5.5 to 7.0 m (18 to 23 ft), by changes in angle of the sign with respect to the vertical in the range of .5 to +5 deg, or by vehicle approach speed. Headlight configuration, as expected, was the dominant factor in the legibility distance of the unilluminated high-intensity sign, further, the high-intensity sheeting can be used without external illumination for overhead sign installations in spite of the observed difference in legibility distances. The average legibility distances in 19 percent less with low beams and 5 percent more with high beams on the high-intensity sheeting without external illumination than on the standard installation without illumination. /Author/

• Record URL:
  • http://onlinepubs.trb.org/Onlinepubs/trr/1976/611/611-006.pdf
• Record URL:
  • https://scholar.google.com/scholar_lookup?title=OVERHEAD+SIGNS+WITHOUT+EXTERNAL+ILLUMINATION&author=D.+Woods&author=N.+Rowan&publication_year=1976
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/0309025877
• Supplemental Notes:
  • Publication of this paper sponsored by Committee on 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:
  • Woods, Donald L
  • Rowan, Neilon J
• Publication Date: 1976

Media Info

• Media Type: Print
• Features: Figures; References; Tables;
• Pagination: pp 38-44
• Monograph Title: Railroad-highway crossings, visibility, and human factors
• Serial:
  • Transportation Research Record
  • Issue Number: 611
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Distance; Headlamps; Height; Highway safety; Legibility; Lighting; Night visibility; Overhead traffic signs; Reflective signs; Sheathing; Traffic signs
• Old TRIS Terms: Tilting
• Subject Areas: Highways; Safety and Human Factors;

Filing Info

• Accession Number: 00163043
• Record Type: Publication
• ISBN: 0309025877
• Report/Paper Numbers: HS-021 004
• Files: TRIS, TRB
• Created Date: Oct 13 1977 12:00AM