It’s barely 10 a.m. on an August day in Hollywood, and the heat is already becoming oppressive. The temperature’s only in the mid-80s, but in the direct sun it feels hotter—and it’s getting worse by the minute. Part of the reason is the ground. The black asphalt of this side street off Sunset Boulevard is sucking up the sun and radiating its heat back out. An infrared thermometer shows the surface temperature to be 112 degrees. By mid-day, it’ll rise above 150.
That’s why a crew of workmen are out here, giant squeegees in hand, spreading a thin coat of liquid over the asphalt. It’s an oil-based sealant, the kind that prevents roads from cracking and potholes from forming. But unlike most street sealants, this one has been specially formulated with a light colored pigment, and within 20 minutes the crew has effectively turned the street from black to white. With the first coat barely dry, the surface temperature’s already dropped nearly 15 degrees.
This is what the city of Los Angeles is calling “cool pavement”—whitening blocks in each of LA’s 15 council districts to see how changing the color of streets can bring down the overall temperature. The street conversions started in May, and the results so far are promising, with officials recording average temperature drops of at least 10 degrees on the pavement itself.
The ambient effect is hard to really feel, and is probably small given the block-long installation is surrounded by other heat-sucking black streets. But city officials are hoping to make the case that this new approach to paving can have an impact. If they can be rolled out on a larger scale, cool pavements could play a key role in adapting the city to a warming climate.