Development of an Index for Estimating Road Weather Severity Based on Energy
We are working with the Indiana Department of Transportation (INDOT) to develop a winter weather severity index that can be used to evaluate the performance of winter weather maintenance. For this project, INDOT specifically requested that the severity index should be based solely on weather/environmental information, in order to provide information that is independent of specific road treatment actions and traffic patterns. This project involves the development of a physically-based analysis of winter severity, using estimates of the hourly rate of deposition of new snow/ice and the energy required melt it. The “Road Weather Severity Based on Energy” (RWSBE) index can be considered an accumulation of energy, beyond that which is available from the environment, needed to melt snow/ice that has been deposited on the road surface on an hourly basis. The environment can assist with snow removal in several ways (i.e., radiation, fluxes of heat, sublimation). The energy not provided by the environment that would be required to melt new snow can be thought of as a measure of the work required to remove the new snow from the road surface. We expect that RWSBE will provide a clearer understanding of the severity of the weather, allowing INDOT to better evaluate their performance, assist with after-action review of recent storms, and improve the reaction to future weather events. Measurable improvements in the winter maintenance decision-making process are expected as a result.