An experiment was conducted to determine which of three light sources (a deluxe white mercury, a high pressure sodium, and low pressure sodium lamp) provided better visibility of test objects representing a variety of visual tasks in terms of size, reflectance characteristics, and color. The objects, representing common roadway hazards, included a full size manikin corresponding to a human figure wearing a blue-grey coat, a medium sized collie dog with colors typical of that breed, and a protion of a car's exhaust system consisting of exhaust pipe and muffler with the usual rusty surface. All of these objects were arranged so that the motorist would see them against their normal backgrounds. Headlights were included as questions had been raised about their effect on visibility measurements using different light sources. The resulting data indicated that roadway objects are most visible in light from high pressure sodium lamps. Low pressure sodium and deluxe white mercury sources ranked second and third, respectively.

  • Availability:
  • Supplemental Notes:
    • Presented at the Annual IES Conference, July 13-17, 1975, San Francisco, Calif.
  • Corporate Authors:

    Illuminating Engineering Society

    120 Wall Street, 17th Floor
    New York, NY  United States  10005-4001
  • Authors:
    • Buck, J A
    • Mc Gowan, T K
    • Mc Nelis, J F
  • Publication Date: 1975-10

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00128531
  • Record Type: Publication
  • Files: TRIS
  • Created Date: May 14 1976 12:00AM