The article examines the limitations of the human eye in adjusting itself to nightime vision. The eye is capable of coping with large differences in colour and apparent brightness of illumination of road surfaces and surroundings during darkness and daylight. During darkness the driver has often to assess not only his own position, speed and direction of travel relative to the layout of the road but also the speed, position and direction of other vehicles with incomplete visual information. Bad weather conditions accentuate his difficulties. The author considers that the most probable common cause of accidents is that the driver did not see the person or vehicle that he hit. Indecision also causes a large number of accidents. Visual illusions which can be dangerous or improve safety are discussed. Accidents at night could be reduced if highway engineers made more use of monocular clues to space perception, especially perspective. Drivers must be made more aware of the nature of visual limitations at low illumination levels when driving at night. For abstracts of parts 1, 3 and 4, see IRRD abstracts nos. 222951, 222953-4. /TRRL/

  • Corporate Authors:

    Illuminating Engineering Society

    York House, 199 Westminster Bridge Road
    London SE1 7UN,   England 
  • Authors:
    • Wright, W D
  • Publication Date: 1976-9-10


  • English

Media Info

  • Features: Photos;
  • Pagination: p. 188-189
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00145386
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Apr 13 1977 12:00AM