To determine the relative severity of winter, state transportation agencies (STAs) have used seasonal equations (the entire portion of the year when snow is expected) to measure whether the weather was exceptionally mild or exceptionally severe. Either mild or severe weather would justify less or more effort in fighting winter storms during the year. With an understanding of the severity of the weather, STAs may be better able to understand whether their performance was good given the weather conditions. Some ofthese models were based on a statistical relationship between the averageweather and the severity of fighting the weather, some were based on the relationship between physical properties and the weather, and others were based on educated guesses mixed with scientific theory. With the exceptionof our current effort, none of these approaches allowed for the evaluation of storm severity between storms or severity between locations (e.g., one route compared to another) although one is now being developed at the University of Iowa. This paper uses Mn/DOT data to determine the relationship between local weather parameters and roadway segment performance information. Although it would seem obvious, the most important relationship estimated is between measureable weather parameters and performance. Because electronic data on weather variables are immediately available, severity can be measured between storms and between geographic locations immediately following a storm. This allowed for measuring performance and weather immediately following a storm to better understand required adjustments for better performance in the future.
Abstract