Generally an east-west route, Interstate 580 overlays several different freeways in the San Francisco Bay Area. The main sections of Interstate 580 include:
Richmond-San Rafael Bridge, which provides the northern east-west crossing over San Francisco/San Pablo Bay waterways
Eastshore Freeway, which is combined with Interstate 80 into Oakland (where you can go East on Interstate 580 and West on Interstate 80 at the same time but in reality heads due south)
MacArthur Freeway, which follows Historic U.S. 50 southeast from Oakland to Hayward
Arthur Breed Freeway, which also follows Historic U.S. 50 and goes due east toward Dublin, Livermore, and the Central Valley, including the Altamont Pass and its windmills
Freeway between Interstate 205 and Interstate 5, which has a 70 mph speed limit, is only four lanes, and is rural in nature.
Interstate 580 provides the best link for traffic from Southern California using Interstate 5 to the San Francisco Bay Area.
Several sections of Interstate 580 were constructed prior to the Federal Highway Act of 1956, including the Livermore bypass and Altamont Pass freeway. Both sections opened as part of U.S. 50 prior to 1956.1 The Richmond-San Rafael Bridge over San Pablo Bay was opened to traffic in 1956 as California 17.
The I-580 corridor was originally incorporated in the longer Interstate 5W loop from near Tracy west to Oakland and north along I-80 to Vacaville and I-505 to Dunnigan. The suffixed route was briefly posted along side Interstate 80 through Berkeley, but decommissioned in favor of Interstates 505 and 580 in 1964.
When it was established, Interstate 580 consisted of the route west from the Central Valley to Livermore Valley and Dublin, through Dublin Canyon into Castro Valley, and north along the MacArthur Freeway to Oakland. A portion of this route west from I-205 overlaid old U.S. 50, and U.S. 48 before that.
This changed in 1984, when Interstate 580 was extended northwest as a result of California State Assembly Bill 2741. The legislation made a number of changes to the state highway system, including renumbering California 17 west from Richmond to San Rafael as an extension of I-580, renumbering California 17 (Nimitz Freeway) south from Oakland to San Jose as the new route for I-880, and created both Interstates 238 and 980.
Even with this renumbering, the section of Interstate 580 between I-80 and the Richmond-San Rafael Bridge was incomplete and still under construction. Temporary Interstate 580 signage was placed along the substandard segment of former California 17, which veered west from I-80 along the Richmond Inner Harbor toward Point Richmond. Upgrades to this segment were completed by the early 1990s.
As approved by AASHTO, California 17 over the Richmond-San Rafael Bridge was previously proposed as Interstate 180 in 1978. Due to the numbering conflict with California 180 in Fresno and across the Central Valley, I-180 was dropped in favor of Interstate 580 in 1983. The bridge was signed as Interstate 580 in 1985.
Western Terminus - U.S. 101 - San Rafael, California
Perspective from Interstate 580 west
Due to the wye interchange at the west end of Interstate 580, motorists headed to U.S. 101 south are directed to take Exit 2A for Sir Francis Drake Boulevard. The surface boulevard winds two miles west along side Corte Madera Creek to connect with the U.S. 101 freeway south to San Francisco. Photo taken 11/26/04.
An end shield for I-580 precedes the diamond interchange (Exit 1B) with Bellam Boulevard. Bellam Boulevard provides a second opportunity to connect with U.S. 101 south to San Francisco via Anderson Drive. Photo taken 11/26/04.
Exit 1B lowers from the concluding Interstate 580 west for Bellam Boulevard and parallel Francisco Boulevard. Francisco Boulevard runs along the east side of both I-580 and U.S. 101 north, serving adjacent industrial businesses and warehouses. Photo taken 11/26/04.
Single lanes from both the Interstate 580 westbound mainline and the on-ramp from Bellam Boulevard combine ahead of U.S. 101 north to Novato, Petaluma and Rohnert Park. Photo taken 11/26/04.
Perspective from U.S. 101 south
Exit 451A separates from U.S. 101 south for Interstate 580 east to Richmond and Oakland. Photo taken by Mike Ballard (07/22/99).
Eastern Terminus - Interstate 5 - south of Tracy, California
Perspective from Interstate 5 north
The northbound split of Interstate 5 with I-580 west is located in a fairly remote area. Despite that, traffic congestion is common on holiday weekends and at other peak periods along the four-lane freeway. Photo taken 12/02.
A rest area lines the north side of Interstate 5 just ahead of the San Joaquin County line. The rest area on-ramp forms an auxiliary lane to the wye interchange where Interstate 580 branches west from I-5 toward Livermore and Dublin. Photo taken 12/02.
With the left-hand ramp in place for I-580 west, a weaving traffic pattern ensues for the continuation of Interstate 5 north to Stockton and Sacramento. Photo taken 12/02.
Interstate 5 turns to travel due north across agricultural areas east of Tracy. Interstate 580 continues the northwestern trajectory between the western foothills and the California Aqueduct to its merge with I-205. Photo taken by Joel Windmiller (03/09/02).