Cool Pavement Experiment in Pacoima, CA Shows Promising Results in Reducing Surface Temperatures

Preliminary results are in from the community-wide cool pavement experiment that has been taking place in the north Los Angeles neighborhood of Pacoima. In July of 2022, the city of Los Angeles partnered with roofing and waterproofing manufacturer, GAF to apply the company’s pavement coating to over 700,000 square feet (~ 65,000 sq. meters) of hard surfaces within a 10-block perimeter. This coating is a water-based epoxy pavement coating that blocks the pavement from absorbing much of the sun’s radiation, thus reducing surface temperature. The coated area includes streets, a school playground, a basketball court, and two parking lots. 

GAF recently shared its first eight months of data. Compared with a neighboring community without cool pavement, Pacoima saw ambient air temperatures measured 2 meters above ground averaging 1.5 degrees F lower during sunny days and up to 3.5 degrees F cooler during a daytime extreme heat event. The pavement itself was 10 degrees F cooler on average on sunny days, and no negative impacts have been observed to date.

“The 2-meter mark was important because that’s kind of a person’s height, and that was critically important,” said Jeff Terry, GAF’s vice president of corporate social responsibility and sustainability. 

GAF staff regularly drive across Pacoima and the neighboring reference community to capture the data, which includes “everything from dew point, barometric pressure, to wind speed to wind direction to temperature to albedo,” Terry said. “We’ve used drones, we use satellite [data], ultimately to … incorporate many, many data points into the evaluation. There are also two weather stations in the community that collect data.”

GAF has been meeting with community members every three to four months, and heard from residents that their tires are wearing less quickly and their shoes don’t stick to the hot road as much as they used to. The local parks and recreation department have stated that  they were able to schedule more summertime basketball leagues because they don’t have to confine players to indoor courts. 

“We’re very excited about the interim findings that we’ve had,” Terry said. “We’re just now digging significantly into the full-year data and only hope that we see improvements even upon what we’re sharing now.”