The United States generates hundreds of millions of discarded tires every year, creating a persistent challenge for waste management, recycling infrastructure and finding useful markets for the material. But in the early 1990s, engineers in Oregon found an unusual way to turn thousands of unwanted tires into part of a highway repair project.
Instead of sending the tires to a landfill or leaving them in stockpiles, officials shredded approximately 580,000 waste tires and used them as lightweight fill beneath a section of U.S. Highway 42 in southern Oregon. The unusual material was selected for a very specific engineering reason: the highway project had triggered movement in an old landslide, and replacing heavy soil with much lighter shredded tires could reduce the load on the unstable ground.
