As winter weather sets in, three recent Clear Roads projects offer resources for helping local agencies maintain their roads—from storing salt and using drones to evaluating additives in deicers. Clear Roads is a research program that brings together transportation professionals and researchers from around the country to drive innovation in the field of winter maintenance.
Salt storage
Properly storing roadway deicing salt in a strategically located facility is critical for efficiency and for preventing water and soil contamination. In a project on salt shed design, researchers considered factors such as covered storage, impermeable surfaces, and efficient drainage systems for minimizing environmental contamination. The project resulted in two practical tools: a spreadsheet for estimating the size of a shed based on storage needs and structure type, and a checklist to guide the design process. In addition, the project report provides recommendations for designing facilities that integrate environmental safeguards, operational efficiency, and adaptability to future demands.
Drone applications
In another project, researchers aimed to identify how drones could be used for winter maintenance operations. Drones have shown potential to increase safety and efficiency when used in a variety of transportation-related practices such as inspections and data collection but have not been explored in detail for use in winter maintenance. This synthesis project surveyed maintenance professionals and reviewed literature about current drone applications within agencies and specific models and product features, including software, flight speed and duration, operational and maintenance requirements, and costs.
Survey respondents noted that many current drone applications could be leveraged for winter operations, such as emergency response and monitoring landslides, road conditions, and traffic. However, challenges with adapting these applications may arise from FAA restrictions, geographic location, and extreme or inclement weather.
Additives
A third project evaluated the effects of common additives used with deicers for winter road maintenance. Combining road salt with corrosion inhibitors, anticaking agents, cold-temperature modifiers, thickeners, or friction enhancers can help deicers work more quickly or remain on pavement longer.
Researchers tested eight solids and prewet solids in the laboratory to evaluate the influence of additives on salt deicer performance, including the freezing point or eutectic temperature, ice-melting capacity, and pavement friction. Freezing-point test results found small differences; because all the solids and prewet solids were composed of rock salt, the freezing point for all products was similar. Regarding the effects on friction, results suggest that additives may lead to reductions or improvements in pavement friction at varying times and in varying conditions, including whether used on asphalt or on concrete pavement.
Although no definitive rankings of additives were achieved, individual agencies can reference the results to help them determine the best deicing additives for their specific situations.