Date of Award

Spring 2021

Project Type


Program or Major

Civil Engineering

Degree Name

Master of Science

First Advisor

Kyle Kwiatkowski

Second Advisor

Erin S. Bell

Third Advisor

Raymond A. Cook


Road salt has become an increasingly unsustainable material when focusing on the economic, environmental, and social aspects, especially for a bridge system. Increasing environmental concerns and regulations have caused questioning and investigations into the repetitive use of road salt for winter maintenance. There is some incorporation of these ideas into practice, such as the New Hampshire Department of Environmental Service (NHDES) Road Salt Reduction Program. Applying excessive amounts of road salt to the roadway and surrounding walkway is necessary to maintain pedestrian and vehicle safety. With the application of considerable quantities of road salt material, costs are substantial when analyzing final costs for application and bridge maintenance. Rehabilitation and replacement of bridge elements and components are further evidence from the effects of this winter maintenance methodology. Identifying best deicer management practice or mitigating the effects of road salt will likely require collaborative decision-making that includes a variety of stakeholders, including departments of transportation, environmental services, and municipalities. There is, however, no holistic analysis of road salt impacts that combines social (safety), environmental, and economic (asset performance) outcomes. This research aims to create a protocol for states and bridge owners to evaluate the impacts of road salt usage by combining the three factors of public safety, environmental health, and routine maintenance. In addition to the protocol development, the research analyzes how de-icing factors are correlated with social, environmental, and bridge performance outcomes by conducting a correlation and linear regression analysis, using New Hampshire as a case study. The hypothesis was that a "low-salt” de-icing approach is predicted to be correlated with higher levels of environmental quality and bridge performance in highly trafficked areas, including less maintenance and longer lifespans. The results do not support the hypothesis, because increased use of road salt does not significantly affect bridge health or deck condition ratings. However, road salt does correlate with a decrease in environmental quality. This developed protocol will be vital to decision-makers as they can incorporate their own specific social, environmental, and economic considerations in their winter maintenance policies when analyzing road salt application. This protocol will be flexible and malleable according to their specific needs and priorities at the time of analysis regarding the type of condition or quality ratings being selected.