Discarded glasses often get dumped in the landfills but engineers in Idaho once found an innovative use of them, solving two problems at once. In 2002, nearly 300 tonnes of discarded glass were headed toward Idaho's waste stream. Then, engineers found a surprising second life for the material — using it as the foundation beneath a highway near Ketchum.
Along a 200-foot stretch of Highway 75, transportation officials placed an eight-to-12-inch layer of crushed glass cullet beneath the road surface. The unusual pilot project turned material that had little value to recycling programs into a structural component of the highway.
