Probe vehicle data for characterizing road conditions associated with inclement weather to improve road maintenance decisions

Connected vehicle concepts can provide an enormously rich new data source that can be used for a variety of safety and performance measure applications. However, to date there are very limited connected vehicle deployments or applications other than graphical color coded maps provided by private sector companies. This paper takes an approach of introducing the concept of tabulating statistical distributions of highway segment space-mean speed to characterize roadway conditions associated with inclement weather. These statistics are computed for segments that correspond to a particular winter weather highway maintenance route. Several examples are presented that illustrates how these statistics can be used to identify the onset of hazardous winter weather and provide outcome oriented performance measure for the roadway condition. During one of the winter storms analyzed, the space mean speed decreased approximately 20mph during a storm and the interquartile range, increased from about 8mph to about 12mph. The paper concludes with a table that summarizes the number of hours, by day, that each snow and ice maintenance route had space mean speeds below 45mph. Using such statistics, geographic influences and alternative strategies for winter operations can be quantitatively assessed to determine the best practices for maintaining high travel time reliability during inclement weather conditions.