Reducing the Dependency on Chlorides & Impacts

Abstract: Chlorides in de-icing and anti-icing materials (road salts and brines) help to keep people safe and traffic moving during snowstorms but also generate undesirable impacts, including corrosions of road infrastructure and harmful effects to the environment and public health. This means a tradeoff exists in road salt usage between the smooth flows of traffic in winter times and the long-term health of the built and natural environments and people. To help achieve a balance in this tradeoff, the State of Indiana needs up-to-date guidelines on various types of chloride-containing materials, alternative construction materials and salt application method, their potential impacts and pros and cons given the conditions of the state.
INDOT has a critical need to develop an agency-level strategy to reduce the use and impacts of chlorides while not compromising the state’s traffic safety and flows in winter times. This study employs a three-pronged approach for an effective development of this future strategy: (i) a comprehensive and comparative analysis of different de-/anti-icing materials and their impacts; (ii) an analysis of operational rules, methods, and tools that crew and staff use in the stages of storage, transporting, and application of chlorides, and (iii) development of a pilot “awareness” program for the INDOT workforce that promotes a culture of sensitivity and discreteness toward salt usage. Through surveys and interviews of experts and INDOT winter operations field crew, this study examines the effectiveness of different types of chloride-containing materials in their de-/anti- icing capability to determine whether there are road salts and brines that can achieve the same performance with less chlorides and/or harmful effects. Furthermore, the study explores the effectiveness of different construction materials that reduce the need for chloride application because of the de-/anti-icing capabilities inherent in them (e.g., hydrophonic cells). Results from this study are expected to inform INDOTs policies and guidelines with respect to the use of chlorides to improve road safety while minimizing environmental impacts.