Interstate 580 (I-580) is an approximately 76-mile-long (122 km) east–west auxiliary Interstate Highway in Northern California. The heavily traveled spur route of I-80 runs from US Route 101 (US 101) in San Rafael in the San Francisco Bay Area to I-5 at a point outside the southern city limits of Tracy in the Central Valley. I-580 forms a concurrency with I-80 between Albany and Oakland, the latter of which is the location of the MacArthur Maze interchange immediately east of the San Francisco–Oakland Bay Bridge. I-580 provides a connection from the Bay Area to the southern San Joaquin Valley and Southern California via I-5, as I-5 bypasses the Bay Area to the east.

A spur route is a short road forming a branch from a longer, more important road such as a freeway, Interstate Highway, or motorway. A bypass or beltway is not considered a spur route as it typically reconnects with another or the same major road.