In the final week of April, the city of San Antonio began installing what it calls cool pavement products to small select segments of roadway in all 10 City Council districts in an effort to counter rising temperatures in the hottest parts of town.

Murray Myers, senior sustainability manager, said the city is using products from four companies that are similar to typical street asphalt pavement materials. But these water-based products contain additives to reflect solar radiation.

Myers said conventional dark pavements increase urban heat island effects in certain areas where there is more roadway and a density of concrete structures.

“‘Cool pavement’ has the added benefit of reflecting more sun and absorbing less heat. In some places, there can be a difference of 10 to 15 degrees compared with places with regular pavement,” Myers said.

Weather permitting, the city is applying cool pavement products to 12 total streets as part of the pilot program, local officials said.

Road crews were scheduled to apply cool pavement in two District 9 streets in the Encino Park neighborhood: Encino Ridge Street between Encino Loop and a nearby cul-de-sac, and Park Farm between Park Hollow and Park Bluff Street.

Local officials said road crews are scheduled to apply cool pavement to a stretch of Clifton Forge Street between Big Meadows Street and Flint Hill Street in the Vance Jackson neighborhood during the week of May 8.

According to Myers, the city initially tested a cool pavement seal coat near the Hays Street Bridge on the east side in November 2021. The current $1 million pilot program is supported by the city’s resiliency, energy efficiency and sustainability program fund.

Myers said the pilot program locations were chosen using various factors, including neighborhoods most affected by heat, pavement condition and the city’s equity approach, which is designed to ensure a more equitable distribution of infrastructure improvements citywide.

According to the city, research shows asphalt collects and retains heat during the day and releases it at night, with downtown, the near east and west sides, and South Texas Medical Center recording temperatures higher than other parts of town.

Higher evening temperatures lead to more energy consumption, more greenhouse gas emissions, air pollution and other harmful effects, city officials said.

“We’re not waiting for climate change to exacerbate the heat in San Antonio; we’re planning and acting now,” Chief Sustainability Officer Doug Melnick said. “Cool pavement is one of the proven tools that we can use to provide relief to the hottest neighborhoods in the city.”

Myers said when all 12 pilot program roads are addressed, the city will study the locations for six months and work with The University of Texas at San Antonio to evaluate cool pavement’s potential to reduce temperatures in the city's hottest areas.

“We’ll see if one product works across the board or if multiple products work,” Myers said.

Local officials said cool pavement is part of a larger approach to climate change and helping to reduce temperatures that includes planting shade trees, expanding vegetated parkways and installing shade structures in the hotter areas of town.