In the present study the first step was to produce headlights with different low beam light distribution. This was carried out by cooperation with headlight manufacturers. The changes and modifications were discussed and suggested by a special group expert in automobile lighting organized within the Swedish road safety administration. The light distribution of these prototypes was measured with special accuracy. The second step was to study systematically in full scale the luminance and contrast prevailing at the moment of detection of obstacles, with and without oncoming headlights. Results from these measurements were then used in the third step where a model for visibility distance calculations was set up. The predictive performance of this model was tested against results from visibility recordings of the headlights with modified low beam distribution. Finally, the model was used for calculations of visibility distances offered by some chosen headlights by driving on a real road with horizontal and vertical curves. Moreover the visibility effects of some special conditions such as curve radius and misaiming were calculated. In this way various headlights can be ranked. The model offers possibilities to specify and develop improved headlight light distribution. /TRRL/

  • Corporate Authors:

    Uppsala University, Sweden

    Department of Psychology, Tradgardsgaten 20
    75220 Uppsala,   Sweden 
  • Authors:
    • Helmers, G
    • Rumar, K
    • Yherbom, U
  • Publication Date: 1977


  • Swedish

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 83 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00170346
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Report/Paper Numbers: Monograph
  • Files: ITRD, TRIS
  • Created Date: Jun 28 1978 12:00AM