Examining the Effects of Winter Road Maintenance Operations on Traffic Safety through Visual Analytics

Many past efforts have been exerted towards describing and quantifying the effects of winter maintenance operations on traffic conditions and safety. As highly granular data on snowplow activity become available, many agencies are becoming interested in incorporating these data in their decision-making processes. However, due to its sheer volume, the processing of snowplow automatic vehicle location (AVL) data has been challenging. In addition, adverse weather conditions are usually accompanied by higher crash rates and also correlate with an increase in maintenance operations. Thus, improper model and variable selection can produce misleading results that indicate maintenance operations lead to a higher crash rate. This paper presents simple visualization tools and analysis methods that examine the effects of winter road maintenance operations on traffic safety by combining various data sources including weather, traffic, snowplow AVL, and crash data. Such intuitive tools and results can help agencies better understand the relationship between winter road maintenance activities and traffic safety.