The City of Phoenix’s cool pavement initiative has shown significant potential to mitigate urban heat, with researchers from Arizona State University (ASU) reporting a surface temperature reduction of up to 12 degrees on treated asphalt streets during summer months. The innovative solution aims to combat the extreme heat of Phoenix summers by applying light gray, reflective coatings to asphalt.

While the reduction in surface temperatures is notable, ASU researchers, led by Jennifer Vanos, Associate Professor at ASU’s School of Sustainability, found smaller yet meaningful decreases in air temperatures. “It’s very hard to decrease air temperature in an open system like this, but even a small drop can be important for energy and water conservation,” Vanos explained.

The reflective surface, however, has trade-offs, as it reflects some of the sun’s heat onto pedestrians. “If someone is walking in the middle of the road, they will feel hotter,” said Vanos, emphasizing the importance of considering placement to avoid areas like playgrounds where active use by children could pose risks.

Since 2020, Phoenix has applied cool pavement to 107 miles of asphalt in 27 neighborhoods, with plans to add eight more miles this season. However, questions remain about the durability of the reflective surface over time. “Phoenix streets provide the ideal testing ground to answer these questions,” said Vanos.

Ryan Stevens, a Phoenix city engineering manager, highlighted the city's commitment to expanding the program while collaborating with researchers to refine its application and effectiveness.

This article was originally published Arizona's Family News here: https://www.azfamily.com/2024/10/18/second-study-says-phoenixs-cool-pavement-has-positive-effect-so-far/.