PHOENIX – The City of Phoenix, in partnership with Arizona State University’s Rob and Melani Walton Sustainability Solutions Service, has released the results of a yearlong study on the effectiveness of the city’s Cool Pavement Program. The second phase of scientific testing reveals that cool pavement coatings continue to significantly reduce surface temperatures by up to 12°F during the summer compared to conventional aged pavement.
The results were presented last week at the Burton Barr Central Library by city officials and ASU researchers, highlighting the ongoing collaboration between the two institutions to explore innovative solutions to combat the urban heat island effect.
Key findings from the study include:
- Cool pavement reduces surface temperatures by as much as 12°F during peak summer heat compared to conventional pavement.
- The application of cool pavement coatings may reduce long-term road maintenance needs, providing both economic and environmental benefits.
- The impact on air temperature remains small but generally positive.
Jenni Vanos, an associate professor at ASU and part of the research team, emphasized Phoenix’s leadership in cool pavement implementation. “Phoenix is pioneering this effort, and while continued testing is crucial, we’re seeing real-world results that point to both immediate and long-term benefits,” she said.
The City of Phoenix first launched its Cool Pavement Program in 2020, applying a lighter-colored CoolSeal coating to streets to reflect sunlight and reduce surface temperatures. The most recent phase of research focused on evaluating a new product, CoolSeal 2.0, also known as “Phoenix Gray,” developed in response to community feedback for a darker, more aesthetically pleasing pavement color.
Brandy Kelso, Interim Director of the Phoenix Street Transportation Department, expressed gratitude for the partnership with ASU. “This collaboration continues to guide our strategy for cool pavement application across the city, and the results of this study provide valuable insights for future projects,” she said.
The findings also suggest that the new cool pavement coating may have a lifespan of up to eight years, doubling that of traditional black seal coats, according to Ryan Stevens, a professional engineer with the city. “By reducing the temperature of the asphalt, the cool pavement coating could extend the lifespan of roads, delaying the need for costly maintenance like milling and overlay.”
For more information on the Cool Pavement Program and to view the full report, visit Phoenix.gov/Streets/CoolPavement.