SR 24 initially heads north before turning east near the Berkeley city limits.

[5] On the other side of the tunnel, SR 24 travels through unincorporated Contra Costa County before entering Orinda.

[6] The Yellow Line of the Bay Area Rapid Transit (BART) system runs in the freeway's center median, excepting the vicinity of the Caldecott Tunnel and the approach to the interchange with Interstate 680.

[12] SR 24 is designated as both the Grove Shafter Freeway, after streets the route travels along (Grove Street was later renamed Martin Luther King Jr. Way), and the William Byron Rumford Freeway, honoring the first African American elected to a state public office in Northern California,[13] from the Caldecott Tunnel to the I-580 interchange segment of the MacArthur Maze, continuing henceforth as I-980 to the terminus with I-880.

[14] Highway 24 was designated in 1932 in conjunction with the ongoing construction of the Broadway Low Level Tunnel (renamed the Caldecott Tunnel in 1960) which opened in 1937,[15] connecting with the new Eastshore Highway and the approaches to the new Bay Bridge by way of Tunnel Road and Ashby Avenue through Berkeley west of the Berkeley Hills, and routed along Mount Diablo Boulevard through Contra Costa County east of the hills.

[1] A 1956 version of Thomas Brothers maps shows Mount Diablo Boulevard where present day Northgate Road is and labeled as Route 24, winding and climbing the mountain.