GUIDELINES FR IMPROVING THE STABILITY OF HEADLIGHT AIM FINAL REPORT

THE SAFETY SIGNIFICANCE OF IMPROPERLY AIMED HEADLIGHTS, THE MECHANISMS BY WHICH THEY DEVELOP MISAIM, AND MEASURES BY WHICH THE GENERATION OF MISAIM MAY BE AVOIDED WERE STUDIED. SURVEYS OF HEADLAMP CONDITIONS IN STATES WITH AND WITHOUT VEHICLE INSPECTION WERE MADE. THE EFFECT OF VARYING DEGREES OF MISAIM ON THE DRIVER'S ABILITY TO SEE ROADSIDE OBJECTS WITH AND WITHOUT OPPOSING TRAFFIC WAS DETERMINED. UPWARD MISAIM OF THE LOW BEAMS INCREASED THE LEVEL OF ILLUMINATION TO THE FRONT TARGETS AT A GREATER DISTANCE, ALTHOUGH IT INCREASED GLARE TO OPPOSING MOTORISTS. DOWNWARD MISAIM REDUCED GLARE TO OPPOSING MOTORISTS BUT ALSO REDUCED TARGET VISIBILITY DISTANCE. WITH HIGH BEAMS, EITHER UPWARD OR DOWNWARD MISAIM DECREASES VISIBILITY DISTANCE. SOURCES OF HEADLAMP MISAIM INCLUEDED: INTERNAL CHANGES WITHIN THE LAMP; IN-SERVICE CHANGES IN TE VEHICLE; VEHICLE LOADING AND OPERATION; HEADLAMP INSPECTION AND ADJUSTMENT; AND HEADLAMP REPLACEMENT. THE MOST SERIOUS CAUSE OF MISAIM IS THAT CAUSED BY CHANGING THE LOADING OF THE VEHICLE. DATA ARE PROVIDED FOR PREDICTING VISIBILITY WITH PROTOTYPE HEADLAMP SYSTEMS. /HSL/

• Supplemental Notes:
  • Contract DOT-HS-024-1-202
• Corporate Authors:

  Southwest Research Institute

  6220 Culebra Road, P.O. Drawer 28510
  San Antonio, TX  United States  78228-0510
• Authors:
  • Hull, R W
  • Hemion, R H
  • Cadena, D G
• Publication Date: 1972

Media Info

• Features: References;
• Pagination: 82 p.

Subject/Index Terms

• TRT Terms: Alignment; Headlamps; High beamed headlamps; Inspection; Low beamed headlamps; Night visibility
• Old TRIS Terms: High beamed headlights; Low beamed headlights
• Subject Areas: Highways; Safety and Human Factors;

Filing Info

• Accession Number: 00222160
• Record Type: Publication
• Source Agency: Highway Safety Literature
• Report/Paper Numbers: No Ar829 Report
• Files: TRIS
• Created Date: Aug 5 1973 12:00AM