Ambient illumination is reviewed in relation to the eye's sensitivity to contrast in the visual field (specifically, that of the traffic environment). Three groups of studies conducted in Sweden and Finland and other countries are reviewed relating to daylight running lights on motor vehicles. The first group of studies concerned detection of oncoming vehicles in rural daylight driving and laboratory evaluation of car conspicuity as a function of car color and background and operation of low beams. The second group covered experimental studies of vehicle detection in the peripheral and central visual field as a function of running light characteristics and level of ambient illumination. The last series investigated the effect of daylight running lights on accident statistics. In particular, a recent and well controlled study in Finland covering the 1968-1974 period is described. It was determined that use of running lights resulted in a 36% reduction in daylight multiple vehicle accidents. Finland and Sweden have laws making low beam or special running lights compulsory for motor vehicles during daylight, and Denmark requires their use for motorcycles (as do several other countries, including France). Norway is expected to introduce a running light law. Two problems concerning running lights remain to be solved: determination of running light optimum characteristics, and relative conspicuity of other motor vehicles which are not presently covered by the law (e.g. tractors, mopeds).

Media Info

  • Features: References;
  • Pagination: 19 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00392295
  • Record Type: Publication
  • Source Agency: National Highway Traffic Safety Administration
  • Report/Paper Numbers: VTI-43, HS-028 903
  • Files: HSL, USDOT
  • Created Date: Feb 28 1985 12:00AM