Extreme heat is the leading cause of weather-related mortality in the United States and is projected to increase in frequency and extent under climate change. Transportation infrastructure is a significant driver of urban heat islands (UHI) and extreme heat micro-environments, including in smaller cities and towns as demonstrated by our current work. Efforts to mitigate UHI often focus on reflecting solar radiation (e.g., increasing surface albedo) and shading (e.g., planting street trees); however, alternative and novel paving materials (ANM) that reduce heat storage or green stormwater infrastructure (GSI) that promotes evaporative cooling offer additional heat mitigation pathways. Sidewalks, which facilitate non-motorized transportation, are relatively low risk, low cost and have low structural requirements compared to other transportation infrastructure and therefore offer a logical test bed for new materials and designs. With thermal comfort, safety and efficiency for users in mind, environmentally responsible designs also minimize material embedded energy and maintain natural ecosystems and processes. ANMs hold significant promise in these arenas however have not yet achieved widespread implementation.
In this project, the University of Vermont team will review the growing literature related to the application of ANMs and GSI to reduce urban heat islands. Interviews will be conducted with public works engineers to assess existing knowledge and potential barriers to implementing alternatives in sidewalk applications. The Vermont team will also assess agency familiarity with alternatives, design standard limitations, regulations, and funding mechanisms.
The Georgia Tech team will conduct supplemental interviews of public works engineers and planners throughout the Southeast region using the survey mechanisms developed by the Vermont team. It is anticipated that some different and perhaps unique technologies and design mechanisms may be identified, given the extreme rainfall and humidity conditions encountered in the Southeast.
The results of this study will allow planners to develop and implement designs that mitigate extreme heat, maintain natural ecosystems and processes, and minimize mitigation material embedded energy. This project will also identify key questions that will drive future research.