State Route 24 (SR 24) is a heavily traveled east–west state highway in the U.S. state of California that serves the eastern side of the San Francisco Bay Area. A freeway throughout its entire length, it runs from the Interstate 580/Interstate 980 interchange (just east of the MacArthur Maze) in Oakland, and through the Caldecott Tunnel under the Berkeley Hills, to the Interstate 680 junction in Walnut Creek. It lies in Alameda County, where it is highly urban, and Contra Costa County, where it passes through wooded hillsides and suburbs. SR 24 is a major connection between the San Francisco–Oakland Bay Bridge/MacArthur Maze complex and the inland cities of the East Bay.
