Hot debate: Phoenix pushes forward with cool pavement despite mixed results

PHOENIX (InvestigateTV) — How hot can pavement get as temperatures rise during the hottest months of the year?

In Phoenix, pavement temperatures have been measured in recent years at above 150 degrees.

That’s why the city is trying to be proactive, installing a specific chemical coating on the roads that’s designed to reflect heat.

However, cool pavement is more expensive and has had mixed results, according to an investigation by our sister station.

Despite that, the city is moving forward with the program. To date, the city has installed more than 140 miles.

Last summer, crews prepared a stretch of road off 19th Avenue, south of Camelback Road, to put down cool pavement.

The city paused the program in 2024, citing issues with the product it was using. They’ve since partnered with another company and are using two different coatings.

“Now we’re catching up and getting back on track,” Ryan Stevens, an engineering manager with the city of Phoenix, said. He continued to tout the benefits.

Our investigators started looking into this back in 2023. On a hot July day, using a heat gun, the asphalt was 153 degrees Fahrenheit. The cool pavement came in at 144 degrees Fahrenheit.

But ASU’s research found that six feet off the ground, the air temperature was only 0.3 degrees cooler during the day and only half a degree cooler at night. That study also found that the light reflected off the road makes it hotter for pedestrians.

Then there’s the price. The city said it is three times as expensive as the traditional coating. Our investigators also found questions about how it’s wearing.

In 2024, the team stopped by five different locations that had been treated with it over the last four years. “We’re always monitoring performance,” Stevens said.

He explained it should last eight years. There’s also another benefit; the city says the cooler surface temperature better protects what’s under the road. “A lot of people are excited that the city is doing something to address urban heat,” Stevens said.

Neighbors the team spoke with weren’t exactly excited. “It’s an incremental change. I don’t really have any problem with it,” Brian Curry said. His road has had cool pavement for several years.

“I don’t know that I really noticed a difference. It does make the street look nicer,” his neighbor, Sophia Sanchez, said.

The city said it would continue to install cool pavement through the end of September, but it couldn’t provide specifics on how many miles that would be.