State Departments of Transportation Perception of Winter Weather Forecasts and Impacts

The annual costs of winter maintenance in the United States is approximately $2.3 billion, which makes measuring performance of state departments of transportation (DOTs) a financially responsible and mission-critical task to improve services, strengthen accountability, and provide better information for effective decision making and resource allocation. While state DOTs are increasingly interested in current trends for winter performance measurements, the data documenting performance are limited. This study identifies winter performance measures and determines the impact of weather information on winter maintenance operations by surveying management personnel from 31 state DOTs. Results indicate that (1) state DOTs are more dependent on weather information for planning rather than tactical purposes, (2) snowfall, road temperature, and freezing rain are the most important weather variables; and, (3) National Weather Service (NWS) forecasts are the most frequent winter weather information used for decisions. However, private weather consulting and internal meteorologist on staff account for the majority of the forecast. Moreover, the survey results also highlight the perceived accuracy of winter weather forecasts from the perspective of state DOT personnel and the importance of the forecasted variables to state DOT operations. For example, the perceived accuracy was highest for air temperature forecasts by the respondents. In addition, respondents perceived greater accuracy for snow occurrence than forecasted snowfall amounts. The survey results also indicate that many state DOT operations rely on non-governmental forecasts for their decision making; underscoring the critical need for continuous, close partnerships between the transportation community and the weather enterprise to ensure winter weather forecast accuracy and cohesive dissemination of hazards.