EFFECTS OF MISAIMED LOW BEAMS AND HIGH BEAMS ON VISUAL DETECTION OF REFLECTORIZED TARGETS AT NIGHT

An analytical study was conducted on a microcomputer to assess the effects of misaimed low beams and high beams on the visual detection of reflectorized targets of different brightness, such as reflectorized warning signs, overhead guide signs, license plates, and post delineators. The study was done at night, on a straight and a left-curved section of highway. The model used computed all the geometric distances and angles necessary for a selected driver-vehicle-reflectorized target situation for each headlamp, the amount of beam illumination that is returned to a driver's eyes for selected environmental and vehicle conditions, and a Multiples of Threshold value. Calculations were performed for a matrix containing 25 passenger-side and driver-side beam misaim combinations (5 x 5 points, identical and nonidentical misaims). The results show that both vertical and horizontal beam misaim may have a detrimental effect upon the detection distance of reflectorized targets in the driving environment: however, the use of brighter retroreflective materials can help to offset the detrimental distance effect in most cases.

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/trr/1989/1247/1247-001.pdf
• Record URL:
  https://scholar.google.com/scholar_lookup?title=EFFECTS+OF+MISAIMED+LOW+BEAMS+AND+HIGH+BEAMS+ON+VISUAL+DETECTION+OF+REFLECTORIZED+TARGETS+AT+NIGHT&author=H.+Zwahlen&author=M.+Miller&author=J.+Yu&publication_year=1989
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• Supplemental Notes:
  • This paper appears in Transportation Research Record No. 1247, Visibility Criteria for Signs, Signals, and Roadway Lighting. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved
• Authors:
  • Zwahlen, Helmut T
  • Miller, Michael E
  • Yu, Jing
• Conference:
  • Symposium on Visibility Criteria for Signs, Signals, and Roadway Lighting, 1988, Minneapolis, Minnesota, USA
• Publication Date: 1989

Media Info

• Features: Figures; References;
• Pagination: p. 1-11
• Monograph Title: Visibility criteria for signs, signals, and roadway lighting
• Serial:
  • Transportation Research Record
  • Issue Number: 1247
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Brightness; Drivers; Headlamps; High beamed headlamps; Highway delineators; Human subject testing; License plates; Low beamed headlamps; Mathematical models; Microcomputers; Night; Overhead traffic signs; Reflective signs; Retroreflectivity; Vision; Visual perception
• Uncontrolled Terms: Post-mounted delineators
• Old TRIS Terms: Driver vision; High beamed headlights; Low beamed headlights; Misaim
• Subject Areas: Highways; Safety and Human Factors; I83: Accidents and the Human Factor;

Filing Info

• Accession Number: 00495498
• Record Type: Publication
• ISBN: 0309049725
• Files: TRIS, TRB, ATRI
• Created Date: Jul 31 1990 12:00AM