Best Practices for Road Weather Management Version 2.0
The Weather and Its Impact on Urban Freeway Traffic Operations
This paper describes how the authors quantified the impact of rain, snow, extreme cold, wind, poor visibility, and pavement surface conditions on freeway traffic flow for the metro freeway region around the Twin Cities. T The research classifies weather events by their intensities and identifies how changes in weather type and intensities impact the speed, headways, and capacity of roadways. Results indicate that severe rain, snow, and low visibility cause the most significant reductions in capacities and operating speeds. Rain (more than 0.25 inch/hour), snow (more than 0.5 inch/hour), and low visibility (less than 0.25 mile) showed capacity reductions of 10 to 17 percent, 19 to 27 percent, and 12 percent and speed reductions of 4 to 7 percent, 11 to 15 percent, and 10 to 12 percent, respectively.
85th Transportation Research Board (TRB) Annual Meeting; Iowa State University, Center for Transportation Research and Education. For an electronic copy of this resource, please direct your request to WeatherFeedback@dot.gov.
Agarwal, Maze, Souleyrette
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