Interstate 580 (California) - Route Description

Route Description

The western terminus of I-580 is north of San Francisco in San Rafael, at a junction with U.S. Route 101. The eastern terminus is with I-5 southeast of Tracy. Leaving San Rafael, I-580 runs next to the San Quentin State Prison before crossing San Francisco Bay over the Richmond-San Rafael Bridge. The road then passes through Richmond.

In Albany, I-580 joins I-80 and then turns east at the interchange known as the MacArthur Maze. From here, it is known as the MacArthur Freeway which runs through Oakland and San Leandro to Castro Valley. About halfway to Castro Valley from the Maze, is an interchange with the Warren Freeway (State Route 13). Between this interchange and Castro Valley, I-580 runs near or along the trace of the Hayward Fault, a major branch of the San Andreas Fault.

In Castro Valley, I-580 turns eastward toward Dublin Canyon before descending into Dublin and Pleasanton. After passing through Livermore, the freeway enters the Altamont Pass. The road emerges in the Central Valley west of Tracy, where, after Interstate 205 splits near the Altamont Speedway, it turns southeastward and terminates by merging with Interstate 5 south of Tracy.

I-580 provides Interstate Highway access between San Francisco and Los Angeles since Interstate 5 runs east of the Bay Area. However, the primary control city listed on freeway signs along eastbound 580 between I-80 and I-205 is instead Stockton, a vestige of when this segment used to be part of U.S. Route 50.