Tire-Derived Aggregate (TDA)

Tire-derived aggregate (TDA) is made from shredded scrap tires and is used in a wide range of construction projects. These uses include retaining wall backfill, lightweight embankment fill, landslide stabilization, vibration mitigation, and various landfill applications. For more information, please visit CalRecycle’s main TDA website.

TDA is…

  • Cost-effective: Less expensive than other lightweight fill materials.
  • High-performing: Lightweight, free-draining characteristics help solve engineering problems.
  • Environmentally friendly: TDA reduces need for mined resources such as pumice and gravel.

Green Roads: TDA

TDA not only helps California divert waste tires from landfills, it also helps civil engineers solve a variety of engineering problems. TDA is lightweight, free-draining and a less expensive alternative to conventional lightweight aggregates.

TDA keeps thousands of tires out of landfills. For more information please visit CalRecycle’s TDA page.

Learn more about CalRecycle’s Grant Programs, which provide financial assistance to local governments specifically to fund TDA projects.

Find out more about Local Assistance and other resources.

Crew spreading TDA on train tracks


  1. What is TDA?
    TDA is a 100 percent recycled material made from waste tires shredded to a specific size unique to a wide range of public works projects and other civil engineering applications.
  2. Is TDA harmful to the environment?
    Studies have shown that TDA has no harmful impact to the environment. However, the specifications, design and construction methods developed for TDA projects are all done in ways that assure that there will be minimal environmental impacts.
  3. Do you need special equipment to transport and place TDA?
    TDA is transported by truck to a project in a 40-foot walking floor trailer which makes it easy to unload material. Once it is delivered to the site, TDA is then spread and compacted by standard earth working equipment.
  4. Why should you use TDA in construction projects?
    The lightweight, free-draining and vibration dampening characteristics of TDA make it a cost-effective solution to a variety of civil engineering applications. It is also a viable reuse alternative to the 10 million waste tires currently being disposed of in landfills.
  5. Where do you get TDA?
    Visit the current list of suppliers in the State of California.

Testimonials/Success Stories

“Tire-derived aggregate is one of the most cost-effective examples of waste tire recycling in California, and is one of the most environmentally friendly uses for construction fill along highways.”
Mark Leary, Acting Director, CalRecycle

“By using TDA we solved engineering problems and also saved taxpayer dollars. Caltrans is excited to continue to use TDA in the future because it works well, is cost-effective and keeps tires out of landfills.”
Malcolm Dougherty, Interim Chief Engineer, California Department of Transportation

“We installed over three thousand linear feet of the TDA track way and the net effect of that was over a million dollars in savings on our project.”
Mark S. Robinson, Chief Engineering & Construction Officer, Valley Transportation Authority


Learn how recycled tires become TDA, see project highlights and experience the many benefits and uses of tire-derived aggregate.

Watch our TDA: A Short Introduction video. YouTube (00:04:29) | Transcript (2015)