The paper describes the evaluation of high intensity warning lights fitted to the rear of vehicles as a protection against rear-end collisions in fog and other conditions of poor visibility. The project was collectively sponsored by a steering committee of manufacturers and the automobile association. The performance of a wide range of lamps in a fog simulation tank was evaluated and was subsequently confirmed by cross-calibration studies in real fog on a motorway. The evaluation took into account driver reaction, the photometric distribution of lamp output, source intensity, shape and size of lens and reflector. Results are compared with the equivalent sight distance of a conventional dipped headlamp and with conventional rear/stop lamp clusters. Tests were carried out with both concrete (light) and black-top (dark) road surfacings; other factors studied included night and day visibility, use of windscreen wipers, mal-adjustment of lamp. The results would be used by the steering committee to determine the case that might be made for the modification of existing or proposed legislation. Also, each manufacturer would be advised how his own proprietary lamps compared with the optimum and would be given information which would help in future development. /TRRL/

  • Corporate Authors:

    Polytechnic of Central London, England

    35 Marylebone Road
    London NW1,   England 
  • Authors:
    • KINNEAR, R G
    • Rose, D M
    • King, A R
  • Publication Date: 1973-6

Media Info

  • Features: Figures; References; Tables;

Subject/Index Terms

Filing Info

  • Accession Number: 00133842
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Report/Paper Numbers: Monograph
  • Files: ITRD, TRIS
  • Created Date: Nov 9 1977 12:00AM