Stockpiled tires are dangerous because they retain heat and easily ignite. The fires—which can burn for months—release unhealthy smoke and toxic oils. Photo: Ohio EPA
Where do our tires go?Of the 290 million tires Americans discard each year, 80% are recycled into fuel, modified asphalt, and other products. Source: Rubber Manufacturers Association

Health nuts and public works teams, meet Robert Amme, your new best friend.

His goal is threefold: to remedy the soreness over-ambitious exercisers experience, to cheaply pave recreation paths, and to minimize the nation's tire stockpiles.

While rubberized asphalt is a growing trend for paving roads, pedestrian paths have remained untouched. That's why Amme and his colleagues created SofTrails, a paving material designed for recreation trails. One trail uses 6000 to 7000 tires from the 290 million that Americans throw out each year.

Amme—a research professor of physics and materials science and the manager of the Environmental Materials Laboratory at the University of Denver—wanted to create something that's environmentally and economically friendly. His product combines asphalt, tire scraps, and a chemical modifier. The result is a crack-resistant trail that's resilient for joggers and firm for cyclists.

What sparked Amme's creativity? “As more baby boomers are told to increase their exercising for health's sake, better paths and trails are in demand,” he says.

Typically, pedestrian paths, tracks, and courts are made of crushed rock bound with asphalt or concrete, a hard surface that can cause joint pain. Amme's material provides cushioning and costs less than other rubberized pavement materials, which use polyurethanes or latex as the binder.

SofTrails has become a must-have among trendsetters—the Colorado DOT and an architect in California are interested in testing it.

Start at home

Solving problems in your own community.

While Minnesota, Wisconsin, and Maryland have eliminated all scrap tire stockpiles, other states still have major problems. Tires disposed of in landfills or illegally dumped in empty lots and forests pose a threat to people and the environment because they catch fire easily and harbor rodents and insects.

According to the Rubber Manufacturers Association, scrap tire regulations vary by state:

  • 38 ban whole tires from landfills
  • 35 allow shredded tires to be placed in landfills
  • 11 ban all tires from landfills
  • 17 allow processed tires to be placed in monofills (landfills dedicated to one type of material)
  • Eight have no restrictions on scrap tires in landfills.

To combat the dangers of tire stockpiles, Illinois joined with the U.S. Environmental Protection Agency to create the Scrap Tire Cleanup Guidebook. The book covers successful cleanup programs and funding, cost recovery, local and regional markets for scrap tires, and project management. Visit