Tanvi Misra is a staff writer for CityLab covering immigrant communities, housing, economic inequality, and culture. She also authors Navigator, a weekly newsletter for urban explorers (subscribe here). Her work also appears in The Atlantic, NPR, and BBC.
Researchers are developing salt-infused asphalt as a solution to slippery streets.
According to a 2015 U.S. Geological Survey report, 43 percent of the annual salt production in the U.S., valued at $2.2 billion, was devoted for melting ice on roads. The city of Rochester, New York, for example, purchased 27,000 tons of salt for $46.80 per ton to prepare for this winter, according to NBC News, and it will spend $1 million to have it spread across the city. But other cities that are less familiar with extremely cold weather struggle to find ice-melting supplies in time for the snow.
A new solution in the works at Turkey’s Koc University might make the annual de-icing process less labor intensive, less harmful to the environment, and perhaps less expensive in the long-run. Researchers there are testing what’s essentially salt-infused asphalt by embedding potassium formate (a salt that dissolves in water and can lower its melting point) in bitumen, an ingredient of asphalt. The American Chemical Society explains more in a press release:
The resulting material was just as sturdy as unmodified bitumen, and it significantly delayed ice formation in lab studies. The new composite released de-icing salt for two months in the lab, but the effects could last even longer when used on real roads, the researchers note. In that instance, the salt-polymer composite would be evenly embedded throughout the asphalt. Thus, as cars and trucks drive over and wear away the pavement, the salt could continually be released — potentially for years.
As someone who slips an average of five times per snowy day, self-melting pavements sound like the best Christmas gift imaginable.