Student Researcher: B. Auffray (ENTPE)

Faculty Advisor: R.L. Bertini and C. Monsere

ABSTRACT: Visibility is one of the basic needs for safe driving. Any type of reduction in visibility can lead drivers to change driving behavior resulting in changes in flow or speed, disorder on the network as a result of braking or driver error, or in the worst case to an incident or a crash. Glare can be caused by sun, headlights of other vehicles or other light sources can cause substantial reductions in vision performance. For freeway operations, glare is primarily associated with headlights from vehicles traveling in the opposite direction at night, is often addressed with median barriers or glare screens. However, the effect of sun-related glare is similar to the impact of headlight glare glare, it can lead to degradation of drivers vision and affect 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 may 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 regression was used to test the effect of the glare issue caused by sunlight on freeway speed/flow and flow/occupancy relationship.

PRODUCTS:

presentation Auffray, B., "An Empirical Investigation of the Impacts of Sun-Related Glare on Traffic Flow." Presented at the 87th Annual Meeting of the Transportation Research Board, Washington, D.C., January 16, 2008.

conferenceproceedings Auffray, B., C. Monsere, R.L. Bertini. , "An Empirical Investigation of the Impacts of Sun-Related Glare on Traffic Flow." Proceedings of the 87th Annual Meeting of the Transportation Research Board, Washington, D.C., 2008.

thesis Auffray, B., "Impact of Adverse Weather on Traffic Conditions on an American Highway." M.S. Thesis, Ecole Nationale des Travaux Publics de l'Etat, France, 2007.

thesis defense Auffray, B., "Impact of Adverse Weather on Traffic Conditions on an American Highway." M.S. Thesis Defense, Ecole Nationale des Travaux Publics de l'Etat, France, 2007.