Environmental, Economic, and Operational Impacts of Roadway Winter Maintenance: Salt Brine Field Evaluation

Abstract

Transportation agencies have been introducing responsible and sustainable winter maintenance practices to alleviate impacts on the environment, human health, vehicles, infrastructure, and reduce costs. Salt brine implementation is an alternative to reduce the amount of salt used in winter maintenance. Laboratory tests have provided evidence for the benefits and effectiveness of salt brine. However, laboratory findings may not reflect complex dynamics in the field. Thus, field data were collected from four counties in Wisconsin to evaluate pairs of study and control roadway segments and quantify material usage, performance, and cost. Data collection consisted of route, equipment, and storm data. The focus of the analysis was to compare total salt and cost per lane-kilometer, time to reach bare/wet conditions, and travel speed. Statistical tests were used to compare observations from study and control routes. Storm data analysis included 70 winter storms. The results of this research showed an overall 34% reduction in salt use and 5.1 fewer hours to reach bare/wet conditions with the study group using mostly salt brine compared to the control group using solid salt. Results suggest that implementation of salt brine in winter maintenance significantly reduces the amount of salt released to the environment and associated costs while maintaining a similar or better level of service. This paper contributes to the existing literature by using field data at study and control routes under the same winter weather conditions to evaluate the impact of salt brine on salt usage, cost, and level of service.