Interstate 205 (I-205) is an east–west auxiliary Interstate Highway in the San Joaquin Valley in Northern California. It runs from I-5 west to I-580. Along with those highways, I-205 forms the north side of a triangle around the city of Tracy. The route provides access from the San Francisco Bay Area to the northern San Joaquin Valley.

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.