MARCH 2011

California utilizes rubberized asphalt concrete for safety

Poor weather and deteriorating roadways can contribute to car accidents, but a tire-derived paving material being promoted in California may help make roads safer.

According to the California Highway Patrol’s most recent Report of Fatal and Injury Motor Vehicle Traffic Collisions, more than 6,500 accidents that occurred in California in 2008 happened during bad weather. Through its Green Roads campaign, the Department of Resources Recycling and Recovery is promoting a type of pavement called RAC (rubberized asphalt concrete) that has been shown to resist deterioration and improve safety in bad weather conditions all while putting to use thousands of tires that would otherwise end up in landfills.

RAC is made from a combination of asphalt and crumb rubber that’s derived from ground up waste tires. RAC offers a number of advantages over traditional asphalt in road applications: the surface stays a darker color longer, which improves driver visibility by providing excellent contrast between road surface and markings; it reduces splash during wet conditions and is skid resistant; and it is more durable and long-lasting than regular pavement. RAC also saves money because it can be applied at half the thickness of traditional pavement, and also requires fewer repairs.

In addition, RAC offers an environmental benefit through the reuse of discarded tires. California generates more than 40 million waste tires every year and while most are recycled, about 11 million end up in landfills, illegal stockpiles, or illegally dumped. Recycling tires and using them in construction and paving projects instead is good for the environment and saves landfill space.

RAC has been used successfully for 30 years, not only in California, but across the country. In Texas, RAC was used in a region where frequent precipitation contributed to high automobile collision rates. A 2003 study conducted by the Texas Department of Transportation one year after RAC was applied found a 43 percent reduction in major accidents under all weather conditions, and a greater than 50 percent reduction in accidents on wet days.