Ashby Avenue

State Route 13
SR 13 highlighted in red
Route information
Defined by
Maintained by Caltrans
Length:	9.730 mi (15.659 km)
Existed:	1964 renumbering – present
Major junctions
South end:	I-580 in Oakland
	SR 24 in Oakland SR 123 in Berkeley
North end:	I-80 / I-580 in Berkeley
Location
Counties:	Alameda
Highway system
State highways in California Interstate U.S. State Pre-1964 History Unconstructed Deleted Freeway Scenic ← SR 12 SR 14 →

State Route 13 (SR 13) is a state highway in California. It is a short loop in Alameda County currently built from Interstate 580 in Oakland to Interstate 80/Interstate 580 in Berkeley.

It consists of three contiguous segments: the Warren Freeway from I-580 to State Route 24 in Oakland; Tunnel Road, a narrow two-lane road to Claremont Avenue in Berkeley; and Ashby Avenue, a main east–west street through south Berkeley to I-80/I-580.

SR 13 is part of the California Freeway and Expressway System. SR 13 is known as the Warren Freeway from Route 24 to Route 580, as named by Assembly Concurrent Resolution 96, Chapter 166 in 1957.

The route currently begins at Interstate 580 near Mills College in East Oakland and continues north as the Warren Freeway, named after former Alameda County District Attorney, California Governor and U.S. Supreme Court Chief Justice Earl Warren. The four-lane freeway takes a largely straight path as it runs through a scenic valley. This valley is enclosed by the far eastern hills of Oakland and a shutter ridge that has been driven northwestward along the Hayward Fault, and the entire freeway lies within the earthquake fault zone of the Hayward Fault. In the event of a major earthquake on the fault, this section of SR 13 may sustain heavy damage. Numerous overpasses have recently undergone extensive seismic retrofitting.