Interstate 580 is a generally east-west freeway that combines 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 from traffic from Southern California using Interstate 5 to the San Francisco Bay Area. At one time, Interstate 580 was considered for designation as Interstate 5W. Although a few Interstate 5W shields were erected, Interstate 580 replaced it shortly thereafter.
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, and it was originally signed as California 17 until it was renumbered in 1983.
Interstate 580 is an original Interstate highway that was originally conceived as part of the Interstate 5W loop. This original route for Interstate 580 was shorter than its current route: initially, it only connected Interstate 80 in Oakland with Interstate 5 south of Tracy and did not include the Richmond-San Rafael Bridge. Interstate 580 followed old U.S. 50 (and U.S. 48 before that) between Oakland and the Interstate 205 split and a new alignment from Interstate 205 southwest to Interstate 5.
This changed in 1984, when Interstate 580 was extended northwest as a result of California State Assembly Bill 2741, which modified the route numbering for California 17 and Interstate 580 in the state highway system. This legislation introduced Interstate 238 and Interstate 980 in Oakland, as well as provided for an extension of Interstate 580 to Marin County and creation of a new Interstate 880 between San Jose and Oakland.
Even with this renumbering, the section of Interstate 580 between Interstate 80 and the Richmond-San Rafael Bridge was incomplete and still under construction. Temporary Interstate 580 signage was placed along theses substandard segments of former California 17 between Interstate 80 and the Richmond-San Rafael Bridge. Upgrades to this segment were completed by the early 1990s.
Around the same time period (1980s), the Interstate 980 designation was given to the under construction California 24 extension into Oakland southwest of Interstate 580, while the California 238 connector was given the number Interstate 238. When Interstate 880 replaced California 17 along the Nimitz Freeway, the former Interstate 880 north of Sacramento became Interstate 80. Old Interstate 80 became Business Loop I-80, with the east-west portion between West Sacramento and Sacramento becoming hidden Interstate 305.
California 17 over the Richmond-San Rafael Bridge was initially designated Interstate 180 in 1978, then recommissioned as an extension of Interstate 580 in 1983. State legislative changes came in 1984, and new signs were placed to proclaim the new extension of Interstate 580 in 1985.
Western Terminus - U.S. 101 - San Rafael, California
Perspective from Westbound Interstate 580
We join Interstate 580 after the Richmond-San Rafael Bridge and the San Quentin interchange (Exit 2B). Westbound Interstate 580 approaches Exit 2A, Sir Francis Drake Boulevard. This is the first connection from westbound Interstate 580 to southbound U.S. 101. To reach northbound U.S. 101, continue west on Interstate 580. Photo taken 11/26/04.
Westbound Interstate 580 reaches Exit 2A, Sir Francis Drake Boulevard. The two main lanes of westbound Interstate 580 continue toward a merge with U.S. 101 north. Photo taken 11/26/04.
The second connection to southbound U.S. 101 is via Exit 1B, Francisco Boulevard to U.S. 101 south. Photo taken 11/26/04.
Interstate 580 ends as it approaches Exits 1A-B, Junction U.S. 101 north to Santa Rosa and south to San Francisco. This is one of the few END shields found in the Bay Area. Photo taken 11/26/04.
Westbound Interstate 580 reaches the offramp to Francisco Boulevard to U.S. 101 South (Exit 1B) and the transition ramp to northbound U.S. 101 (Exit 1A). The transition ramp narrows from two lanes to one lane. Photo taken 11/26/04.
The single through lane merges with the onramp from Francisco Boulevard, then prepares to merge onto U.S. 101 northbound. Photo taken 11/26/04.
Traffic from westbound Interstate 580 merges onto northbound U.S. 101 in San Rafael. Continue north on U.S. 101 to Novato, Petaluma, and Rohnert Park. Photo taken 11/26/04.
Perspective from Southbound U.S. 101
Southbound U.S. 101 at Junction Eastbound Interstate 580 in San Rafael. Interstate 580 over the San Rafael-Richmond Bridge used to be California 17, and it was briefly designated as Interstate 180 in the mid-1980s. Photo taken by Mike Ballard (07/22/99).
Westbound Interstate 580 approaching Junction Interstate 80. Underneath the green overlays on this sign are old U.S. 40 and U.S. 50 shields. Photo taken 11/26/04.
Prior to 1984, Interstate 580 ended at this point. Traffic used to have an option between eastbound and westbound Interstate 80 at this interchange. With the extension of Interstate 580, Interstate 580 continues west via Interstate 80 east along a freeway that is actually traveling north. Photo taken 11/26/04.
A tall flyover ramp carries the connection from northbound Interstate 880 to Interstate 80 over the two-lane mainline of Interstate 580. Back when Interstate 580 ended here, this ramp did not exist. Photo taken 11/26/04.
Westbound Interstate 580 formerly ended here as it merged onto eastbound Interstate 580. Now, the two routes share pavement from here north to the split in Albany. Photo taken 11/26/04.
Perspective from Westbound Interstate 80/Eastbound 580
On this rainy December day along westbound Interstate 80/eastbound Interstate 580, we approach the Maze. Cited every morning and evening for its notorious traffic delays, Interstate 580 used to end at this interchange (before it was extended in 1984). This sign assembly shows that Interstate 580 and 880 traffic should remain in the left lanes, while Interstate 80/Bay Bridge traffic should remain in the right lanes. The High Occupancy Vehicle (HOV) lanes to the left have direct access to Interstate 80 west even though they are on the left. Interstate 580 and 880 do not have direct HOV access at this time. The westbound Interstate 80 HOV lanes require three occupants to be considered a carpool. Note the recently replaced signage for Interstates 580 and 880; this is the new standard for signage initiated by Caltrans in 1999. Photo by 12/30/01.
This sign reflects the exact lane allocation for each of the three roads: Interstates 580, 880, and 80 from left to right. No mention is made of access to California 24 at this interchange, but other signs recommend using Interstate 580. Photo taken 12/30/01.
Sign assembly for the three routes, next to flyover for carpool/HOV lane from left side of freeway. This is the beginning of the Maze Interchange. Interstate 80 exits from the Eastshore Freeway at this point, while Interstate 580 and 880 traffic continue south before separating. Photo by 12/30/01.
These newly placed reflective signs show the split between Interstate 580 eastbound and Interstate 880 southbound. This marks the beginning of extant Interstate 880. There are no BEGIN signs located here. Photo taken 12/30/01.
Eastern Terminus - Interstate 5 - south of Tracy, California
Perspective from Northbound Interstate 5
Northbound Interstate 5 approaching Junction Interstate 580, two miles. This interchange is in a fairly remote area, but there is generally plenty of traffic, as this route is the primary route from Los Angeles to San Francisco. On holiday weekends, delays and congestion are common on this four-lane freeway. Photo taken 12/02.
Rest area located along northbound Interstate 5 just prior to the Interstate 580 interchange. There are few exits along this stretch of Interstate 5, and this is the last rest area before entering the urban San Francisco Bay Area. Photo taken 12/02.
This sign is the first to warn northbound Interstate 5 motorists to stay in the right lanes immediately after the on-ramp from the rest area. Photo taken 12/02.
Advance signage for the northbound Interstate 5 and Interstate 580 interchange. Interstate 5 traffic should stay right, while Interstate 580 traffic should remain left. Photo taken 12/02.
Northbound Interstate 5 at Junction Westbound Interstate 580. Notably, Interstate 5 exits off of itself, while through traffic continues on Interstate 580. There is an END Interstate 580 shield assembly heading eastbound. First photo taken by Joel Windmiller (03/09/02) and second photo taken 12/02.
Perspective from Westbound Interstate 580
View of westbound Interstate 580 after the split from northbound Interstate 5. Photo taken 12/02.