Empirical Investigation of Impacts of Sun-Related Glare on Traffic Flow

Visibility is one of the basic needs for safe driving. Any type of reduction in visibility can lead drivers to a crash or incident, in the worst case, or to disorder on the network as a result of braking or driver error. Glare caused by sun, headlights of other vehicles or other light sources can cause significant reductions in vision performance. Glare is primarily associated with headlights from vehicles traveling in the opposite direction at night, which is often addressed with median barriers or glare screens. However, the effect of sun-related glare is similar to the impact of headlight glare—it can lead to degradation of drivers’ vision and a drop in driving performance. The occurrence of glare will vary according to time (only on certain days and times when the sun is low in the sky) and location (only on particular combinations of roadway horizontal and vertical geometry). Rather than investigating any direct relationship that could exist between reported crashes and glare, the objective of this paper is to examine the potential impact between measured traffic flow characteristics and the potential for vehicles to be impacted by sun glare. A method based on multiple regressions to test the effect of the glare issue caused by sunlight on freeway speed/flow and flow/occupancy relations is used.

• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Monsere, Christopher M
  • Auffray, Benjamin
  • Bertini, Robert Lawrence
• Conference:
  • Transportation Research Board 87th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2008-1-13 to 2008-1-17
• Date: 2008

Language

• English

Media Info

• Media Type: DVD
• Features: Figures; References; Tables;
• Pagination: 11p
• Monograph Title: TRB 87th Annual Meeting Compendium of Papers DVD

Subject/Index Terms

• TRT Terms: Glare; Incident detection; Night visibility; Operations; Safety factors; Sunlight; Traffic flow; Traffic incidents; Visibility
• Subject Areas: Administration and Management; Highways; Operations and Traffic Management; Planning and Forecasting; Safety and Human Factors; I72: Traffic and Transport Planning; I83: Accidents and the Human Factor;

Filing Info

• Accession Number: 01099272
• Record Type: Publication
• Report/Paper Numbers: 08-0773
• Files: TRIS, TRB
• Created Date: May 21 2008 7:05AM