TRANSITIONAL ADAPTATION IN TUNNEL LIGHTING

THE PHENOMENON OF TRANSITIONAL ADAPTATION CONCERNS CHANGES IN VISIBILITY RESULTING FROM SUDDEN INCREASES AND DECREASES IN THE PREVAILING LUMINANCE LEVEL OF THE VISUAL FIELD. SUDDEN TRANSITIONS IN TUNNEL LIGHTING ARE ABLE TO PRODUCE A "BLACK-OUT" EFFECT AT THE ENTRANCE OF A TUNNEL, CREATE BLIND SPOTS AT BOTH ENTRANCES AND EXITS, AND REDUCE TRAFFIC SPEED THROUGH THE TUNNEL. IN ADDITION, DISCONTINUOUS OR SPACED LIGHTING FIXTURES WITHIN A TUNNEL MAY PRODUCE A FLICKERING EFFECT THAT CAN ALSO REQUIRE TRANSITIONAL ADAPTATION. WHEN THE EYE IS PRESENTED WITH A SUDDEN INCREASE OR DECREASE IN THE PREVAILING LEVEL OF ILLUMINATION, A TRANSIENT BURST OF ACTIVITY OCCURS IN THE RETINA WHICH IS TRANSMITTED TO THE BRAIN, SIGNALLING THIS CHANGE. IF THE INDIVIDUAL IS ASKED TO PERFORM A VISUAL TASK AT THIS TIME, A GREATER CONTRAST BETWEEN THE VISUAL STIMULUS AND ITS BACKGROUND WILL BE REQUIRED, BECAUSE THE VISUAL SYSTEM IS BUSY HANDLING INFORMATION RELATED TO THE CHANGE IN LUMINANCE LEVEL. EXPERIMENTS HAVE BEEN CONDUCTED AT THE UNIVERSITY OF ROCHESTER AND THE UNIVERSITY OF VIRGINIA TO SIMULATE THIS PHENOMENON UNDER TYPICAL DRIVING CONDITIONS, SUCH AS DRIVING IN TUNNELS OR AT NIGHT. THE EXPERIMENTS ARE DESCRIBED, AND THEIR RELEVANCE FOR THE DESIGN OF HIGHWAY LIGHTING SYSTEMS IS TREATED BRIEFLY.

  • Authors:
    • Rinaldducci, E J
  • Publication Date: 1972-8

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00221784
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Feb 3 1973 12:00AM