DIRTY HEADLIGHTS - FREQUENCY AND VISIBILITY EFFECTS

IN ORDER TO ESTABLISH THE EXISTENCE AND SIZE OF THE PROBLEM OF DIRT IN HEADLAMPS THREE EXPERIMENTS HAVE BEEN CARRIED OUT. IN THE FIRST EXPERIMENT DIRT LAYERS WERE SYSTEMATICALLY COLLECTED UNDER VARIOUS ROAD CONDITIONS. THE WETNESS OF THE ROAD WAS FOUND TO BE IMPORTANT. IN THE SECOND EXPERIMENT THE LIGHT REDUCTION CAUSED BY DIRT ON CARS IN TRAFFIC WAS MEASURED. IT WAS FOUND THAT EVEN IN DRY WEATHER ON SEEMINGLY CLEAN ROADS LIGHT REDUCTION IS NORMALLY 10 - 20 PERCENT. IN BAD (SLUSHY) ROAD CONDITIONS FEW CARS HAVE LIGHT REDUCTION BELOW 50 PERCENT. DRIVERS NORMALLY DO NOT REACT TO LIGHT REDUCTION BELOW 60 PERCENT. IN THE THIRD EXPERIMENT VISIBILITY REDUCTION IN NIGHT DRIVING WAS MEASURED AS A FUNCTION OF LIGHT REDUCTION. 60 PERCENT LIGHT REDUCTION CAUSES A 20 PERCENT REDUCTION FO HIGH VISIBILITY AND A 15 PERCENT REDUCTION OF LOW BEAM VISIBILITY. /TRRL/

• Corporate Authors:

  Uppala University, Sweden

  Department of Psychological Laboratory
  Uppsala,   Sweden 
• Authors:
  • Rumar, K
• Publication Date: 1973

Language

• English

Media Info

• Features: Figures; References; Tables;
• Pagination: 12 p.

Subject/Index Terms

• TRT Terms: Experiments; Frequency (Electromagnetism); Headlamps; Light; Low beamed headlamps; Moisture content; Night visibility; Visibility
• Uncontrolled Terms: Wet conditions
• Old TRIS Terms: Low beamed headlights
• Subject Areas: Highways; Safety and Human Factors;

Filing Info

• Accession Number: 00222405
• Record Type: Publication
• Source Agency: Transport and Road Research Laboratory (TRRL)
• Report/Paper Numbers: Report No. 36, HS-014 641
• Files: HSL, TRIS
• Created Date: Jul 16 1983 12:00AM