U.S. Environmental Protection Agency data shows the difference in nighttime temperatures in heat island areas can be as much as 22 degrees warmer than temperatures measured outside such locations. This leads to more energy consumption, greenhouse gas emissions, air pollution and other harmful effects.

Cool pavement is a road treatment made with no harmful chemicals—just asphalt, water, an emulsifying soap, mineral fillers, polymers and recycled materials—applied on top of existing asphalt pavement. Because the surface reflects, rather than retains heat, it has the potential to offset rising nighttime temperatures.

In 2020, portions of eight neighborhoods in Phoenix received cool pavement asphalt coating treatment in areas already in need of pavement preservation. The city partnered with Arizona State University researchers to conduct scientific tests using thermal imaging by helicopter flyovers and temperature sensors embedded in the pavement surface, studying how it could mitigate the urban heat island effect. In October 2021, the pilot program ended and cool pavement has become a regular program for the city’s Street Transportation Department.

Similarly, 1 million square feet of roads in Los Angeles have been covered with solar-reflective paint in the GAF Cool Community Project, which includes colorful murals by a local artist on a basketball court, a school playground and a parking lot.