in City of Phoenix Cool Pavement Evaluation (COPE)

Many cities around the world, including the City of Phoenix, are experiencing elevated temperatures due to the built environment that are exacerbated by climate change. Paved surfaces with impervious materials, such as asphalt concrete (roads, sidewalks, parking lots, etc.), absorb and store heat during the day and release this heat overnight creating higher temperatures than surrounding rural areas. This phenomenon is known as the Urban Heat Island (UHI) effect. With paved surfaces comprising about 40% of the urban land area in Phoenix, they are often considered one of the primary causes of the UHI. One of many strategies to mitigate increased temperatures and reduce heat storage in pavements is the use of coatings that reflect (rather than absorb) solar radiation to reduce the heat absorbed by the pavement, thus reducing surface temperatures. Lowering surface temperatures and the heat retained in the built urban environment may help reduce elevated day and nighttime air temperatures. Such reflective coatings are easy to apply to existing paved surfaces and, in most cases, use light-colored pigments and materials to increase reflectivity compared to traditional asphalt concrete roads. The City of Phoenix recently initiated the Cool Pavement Pilot Program in which the City applied the product CoolSeal by GuardTop® to 36 miles of residential neighborhood roads and one public parking lot. This effort resulted in the most miles of road surface coverage with a reflective coating of any municipality globally. It is designed to achieve lower pavement surface temperatures through its lighter color and reflectivity. One neighborhood in each of the eight council districts of Phoenix was chosen for application of CoolSeal in consultation and with the support of the City Council Offices. Data from the Phoenix Cool Pavement Pilot Program are shared through the DesignSafe Data Depot to be accessed by researchers, municipal officials, and other stakeholders seeking to understand the impacts of this particular heat mitigation strategy and/or who may be considering a similar implementation in their jurisdiction.