ASU teams up with city of Phoenix, releases results of latest cool pavement testing

PHOENIX — Arizona State University partnered with the city of Phoenix Street Transportation Department to evaluate the new CoolSeal 2.0 pavement coating, a continuation of the city’s Cool Pavement Program.

Last week, they presented the results. ASU researchers discovered that the use of this cool pavement reduced the surface temperature of some roads by as much as up to 12 degrees.

In addition, research suggested cool pavement could reduce road maintenance needs and costs and the impact it has on air temperature thus far appears to be small but beneficial.

“While continued testing will be crucial in the long-term, there is no way to know how this works in the real world unless you test it in the real world, and we’ve started that important effort here in Phoenix,” Jenni Vanos, associate professor at ASU and member of the research team that conducted the study, said in a release.

The Phoenix-ASU partnership extended into Phase 2 in 2022, building upon findings from Phase 1 in 2021. Since then, researchers continued digging into the thermal performance of the cool pavement surfaces in residential areas.

Tested products included the CoolSeal 2.0 in response to Phoenix residents wanting a darker color and different formulations.

“The lifespan of the cool pavement seal coat is approximately eight years, as opposed to four years, for a traditional black seal coat,” said Ryan Stevens, a professional engineer with the Phoenix Street Transportation Department. “Since the cool pavement seal coat reduces the temperature of the asphalt underneath the surface, this will lead to a longer lifespan for the road, increasing the service life before the next major maintenance activity, like a mill and overlay.”