This paper addresses the problem of the specification of lighting for the automobile driving operation. The empirical relationship between a measure of driver visual performance and several methods of quantifying visibility is explored in an effort to develop roadway lighting specifications based on visibility needs. Physical contrast, equivalent contrast, relative contrast sensitivity, and glare exposure are discussed. Field measurements of the visual performance of 941 unalerted motorists are analyzed, and a precise method of quantifying visibility is identified. The form of the suggested visibility term uses physical contrast, contrast sensitivity, and a disability glare factor. A method of prescribing visibility in terms of safe stopping requirements is discussed. Follow-up research that will enhance the reliability of the measures, extend the general applicability of the concept, and further develop the prescription approach is outlined.

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  • Supplemental Notes:
    • Presented at a symposium, conducted by TRB, September 4-7, 1975. 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
  • Corporate Authors:

    Transportation Research Board (TRB)

    Washington, DC   
  • Authors:
    • Gallagher, Vincent P
    • Meguire, Patrick G
  • Conference:
  • Publication Date: 1975

Media Info

  • Media Type: Print
  • Features: Figures; References; Tables;
  • Pagination: pp 40-52
  • Monograph Title: Driver visual needs in night driving: proceedings of a symposium conducted by the Transportation Research Board, September 4-6, 1974
  • Serial:

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Filing Info

  • Accession Number: 00129392
  • Record Type: Publication
  • Report/Paper Numbers: HS-017 803
  • Files: TRIS, TRB, ATRI
  • Created Date: Apr 21 1976 12:00AM