Route 210, consisting of the contiguous segments of Interstate 210 (I-210) and State Route 210 (SR 210) forming the Foothill Freeway, is a major east—west state highway in the Greater Los Angeles area of the U.S. state of California. The western portion of the route is an auxiliary Interstate Highway, while the eastern portion is a state highway. The entire route was upgraded to Interstate Highway standards by 2007, and the California Department of Transportation (Caltrans) has requested permission to re-sign the eastern portion as an Interstate Highway.