Caltrans using old bottles to resurface Northern California highway in eco-friendly trial

California is resurfacing a section of a Northern California highway with an unusual but promising eco-friendly product — recycled plastic bottles.

It’s an experiment in sustainable highway construction, Caltrans officials say. The project involves grinding up the top 3 inches of the road’s asphalt surface, adding repurposed plastic to the mix in the form of a liquid bond, and then laying it back down in place and packing it with a roller.

State Department of Transportation officials say it’s a first on a California highway, and if it proves to be durable, they’ll do more of it around the state, saving time, money and reducing truck emissions by eliminating the need to have trucks bring new material in.

The test area for Caltrans’ “green” highway is a short, 1,000-yard section of Highway 162 near the Oroville Airport in Butte County, just west of the town of Oroville.

The key new ingredient will be 150,000 plastic soft drink and water bottles reformed into a liquid polymer binder.

“This liquid plastic serves as a kind of glue or adhesive to hold the asphalt together, like mixing water and flour for a dough,” Caltrans spokesman Gilbert Mohtes-Chan said. The state has historically used petroleum products as the adhesive in the asphalt.

It’s worked well in other tests, officials said. But this is test area will take a pounding from farm vehicles and commercial trucks.

“We’re excited about introducing a new sustainable technology and helping pave the way for utilization of recycled plastics throughout the state,” said Caltrans District 3 area Director Amarjeet Benipal. “This process is better for the environment because it keeps plastic bottles out of landfills and helps reduce greenhouse gas emissions and reliance on fossil fuels.”

The bottles are made of PET single-use plastic, the type of plastic not only used for water and soda bottles, but also for other food packaging.

This story was originally published July 30, 2020 at 4:51 PM.