PHOENIX — From Phoenix neighborhood streets to a big shopping center — cool pavement is now being installed at Desert Ridge Marketplace.
The city of Phoenix now has more than 100 miles of cool pavement installed and plans to have 118 miles by the end of 2023. The city said the average subsurface temperature is 4.8 degrees cooler compared to traditional asphalt.
Desert Ridge Marketplace in north Phoenix decided to install a portion of cool pavement at its large shopping center, looking for different ways to promote sustainability and also help out with testing.
Tim Ray, the general manager, told ABC15 about 63,000 square feet of cool seal will be in place in the parking lot south of the HomeGoods and Marshalls stores.
“We wanted a high-traffic area that we can really test the product in and have a large enough area that we could do an effective test,” he said.
David Sailor, the director of the Southwest Integrated Field Laboratory at Arizona State University, said the cool pavement does not absorb as much of the sun as regular asphalt does.
“What this surface does in contrast to a dark seal coat is, we’re just seal coating with a lighter color, more reflective, more solar reflective surface so that the energy of the sun. Instead of 95% of it being absorbed and dealt with by the city, we only have about 70% absorbed by the surface,” Sailor said.
Sailor has worked with the city of Phoenix on the cool pavement in neighborhoods. He said trying to gain data near homes is a different challenge.
“One of the challenges is every neighborhood is different. With a different variety of land cover, landscapes, some people watering their lawns at some times of the day and not at others, and so forth,” he said. “There’s a tremendous amount of variability. There’s also shade from trees that’s affecting the temperature of the streets. It’s difficult to isolate the temperature signals in those smaller area tests.”
Now with the cool pavement being laid down at the Desert Ridge Marketplace, Sailor said it’ll be easier to see the impacts.
ASU installed several weather stations around the parking lot to capture temperatures. They also put some sensors underground and throughout the next year, they’ll also be driving on the cool pavement and regular, black-sealed pavement nearby to take measurements.
Sailor said he knows the cool pavement has an impact. But they’re going to get a better look at how big the impact is and if there are any “other consequences we need to take into account.”
One Phoenix neighborhood in late 2022 had its cool pavement damaged due to heavy rain.
Ray said the cool pavement seal will stay in the area for about a year as they and Sailor test it out, then the shopping center will take a look and see if they want to expand it to other areas or stay with the traditional black seal.
“The cool seal is about three times the cost of a traditional seal coat, so obviously that plays a role in the viability of its use,” Ray said. “Obviously, if it has a substantial impact to sustainability, we’re anxious to look at how we can use it.”
