Empirical Studies on Traffic Flow in Inclement Weather
Weather causes a variety of impacts on the transportation system. While severe winter storms, hurricanes, or flooding can result in major stoppages or evacuations of transportation systems and they cost millions of dollars, day-to-day weather events such as rain, fog, snow, and freezing rain can have a serious impact on the mobility and safety of the transportation system users. These weather events can result in increased fuel consumption, delay, number of accidents, and significantly impact the performance of the transportation system. The overall goal of the research work undertaken in this study was to develop a better understanding of the impacts of weather on traffic flow. The research was intended to accomplish the following specific objectives: (1) study the impact of precipitation on macroscopic traffic flow parameters over a full range of traffic states; (2) study the impact of precipitation on macroscopic traffic flow parameters using consistent, continuous weather variables; (3) study the impact of precipitation on macroscopic traffic flow parameters on a wide range of facilities; (4) study regional differences in reaction to precipitation; and (5) study macroscopic impacts of reduced visibility. The work documented in this report was conducted in two parts: (1) literature review and development of a data collection and analysis plan, and (2) analysis and interpretation of the results. The recommended plan combined the use of macroscopic traffic data archives with archived weather data in order to meet the research goals that include achieving better understanding of the impacts of weather on macroscopic traffic flow. The results of the research conducted for this study were helpful identifying weather impacts of traffic flow in the three cities studied, Minneapolis-St. Paul, Baltimore and Seattle. No impacts were found on traffic stream jam density, but both rain and snow did impact traffic free-flow speed, speed-at-capacity and the capacity and speed parameters varied with precipitation intensity. The results of these analyses are documented in the report. This report concludes with some recommendations of future research related to weather and traffic flow. Several ideas are presented including enhancing the macroscopic analysis used in this study. Additional work is proposed related to human factors and microscopic traffic modeling.
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Supplemental Notes:
- This research was funded by the U.S. Department of Transportation, University Transportation Centers Program.
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Corporate Authors:
Virginia Polytechnic Institute and State University, Blacksburg
Virginia Tech Transportation Institute
3500 Transportation Research Plaza
Blacksburg, VA United States 24061Virginia Department of Transportation
1401 East Broad Street
Richmond, VA United States 23219Mid-Atlantic Universities Transportation Center
Pennsylvania State University
201 Transportation Research Building
University Park, PA United States 16802-4710Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC United States 20590 -
Authors:
- Rakha, Hesham Ahmed
- Farzaneh, Mohamadreza
- Arafeh, Mazen
- Hranac, Rob C
- Sterzin, Emily
- Krechmer, Daniel
- Publication Date: 2007-6
Language
- English
Media Info
- Media Type: Print
- Edition: Final Report
- Features: Appendices; Figures; Photos; References; Tables;
- Pagination: 114p
Subject/Index Terms
- TRT Terms: Data collection; Evacuation; Floods; Fuel consumption; Hurricanes; Impact studies; Literature reviews; Macroscopic traffic flow; Precipitation (Meteorology); Rain; Snow; Traffic delays; Traffic flow; Traffic speed; Weather conditions; Winter
- Geographic Terms: Baltimore (Maryland); Minneapolis (Minnesota); Saint Paul (Minnesota); Seattle (Washington)
- Subject Areas: Energy; Highways; Hydraulics and Hydrology; Operations and Traffic Management; Planning and Forecasting; Safety and Human Factors; I72: Traffic and Transport Planning; I82: Accidents and Transport Infrastructure;
Filing Info
- Accession Number: 01056137
- Record Type: Publication
- Files: UTC, TRIS, USDOT, STATEDOT
- Created Date: Aug 29 2007 4:10PM