Adverse weather conditions negatively impact mobility and safety of drivers on roads. In an average year, approximately 21% of U.S. highway crashes are weather-related. Collectively, these crashes result in over 5,300 fatalities each year. Using 2019 weather and traffic data along Colorado Highwa... Show moreAdverse weather conditions negatively impact mobility and safety of drivers on roads. In an average year, approximately 21% of U.S. highway crashes are weather-related. Collectively, these crashes result in over 5,300 fatalities each year. Using 2019 weather and traffic data along Colorado Highway 119 between Boulder and Longmont, this research analyzed the relationship among adverse weather and traffic conditions. The data were classified into distinct weather types and the direction of travel. Traffic information included metrics such as volume, speed, trip length, trip duration, and the purpose of travel. The data showed that snow days had a smaller traffic volume than clear and rainy days, with an all-day volume of approximately 18,000 vehicles for each direction of travel as opposed to 21,000 vehicles for both clear and wet conditions. Despite the volume reduction, the data showed that the percentage of travel between home and work locations was 21.4% throughout a snow day compared to 20.6% for rain and 19.6% for clear days. The overall traffic volume reduction during snow days is likely due to drivers deciding to avoid commuting; however, the relative increase in the home-work percentage is attributable to less discretionary travel in lieu of essential work travel. In comparison, the increase in traffic volume during rainy days is due to commuters being less likely to walk, bike, or take public transit during inclement weather. This work demonstrates the importance of analyzing the effects of human behavior during adverse weather travel.m. Show less
