Originally Posted by SPUR
Recommendation 3.1: Plan and build a new subway line through SOMA.
SPUR recommends that we begin planning for a second subway line through the South of Market Area in
San Francisco as the highest long-term priority. It is probable that such a new subway line could be
designed and built by BART, and could be implemented incrementally and coordinated with the
extension of the downtown office district along its route.
This line would eventually link up with a second Transbay Tube to the East Bay. However, it should be
designed in a way that doesn’t preclude extension west to serve other neighborhoods of San Francisco,
much as the current BART alignment serves the Mission District. This new subway line is needed
because the existing tube, the Market Street Subway and stations, cannot carry the expected ridership
growth into downtown San Francisco. In addition, the existing Market Street office core will be
effectively built out, and the most likely new development areas lack direct regional transit access.
Using the criteria enumerated here, a key objective is to design a system that can be implemented
incrementally. We should first build off of our existing system and improve existing transit services first
and then build new transit capacity. This will enable the maximization of existing resources and allow
sufficient time to plan and incrementally build new transit resources.
We do not need to build the new tube first. Instead, we need to deliver a new downtown San Francisco
subway as a first step. SPUR recommends that we build the new line through SOMA, under either
Folsom Street or Townsend Street. The new line will extend from a three-track turnback between the
Civic Center and 16th Street stations, identified as a midterm reliability project and extend through
SOMA toward the Bay. SPUR | March 2009
The Future of Downtown San Francisco 60
SPUR believes that either Folsom Street or Townsend Street would be appropriate for the new alignment.
Each has strengths and weaknesses, and we believe a more detailed transportation and land use study
would best identify the superior option. Therefore, SPUR has not chosen a recommendation between
these two options. However, a new regional subway line under at least one of these two corridors.
A Folsom Street alignment would have several advantages:
• It would relieve BART’s station crowding by placing new stations within walking distance of the
current Market Street facility.
• It would provide redundancy in case one line is temporarily taken out of service by accident or
repair. Then passengers can shift to other line with little trouble.
• It could support the contiguous growth of downtown, as the Mid-Market Street area is one of the
logical extensions of downtown that is close to the current downtown than West SOMA It would
allow the creation of new office markets near Fourth Street north of the freeway, and the
neighborhoods of western SOMA and near the Transbay Terminal. It would provide a connection
to the proposed Caltrain downtown extension and High Speed Rail at a Transbay Transit Center
Station, and to the T-Third and Central Subway lines at a Moscone Center/4th/Fourth Street
The Townsend alignment would have several benefits:
• It would reinforce an emerging neighborhood that has seen significant new growth in recent years
— in both housing and jobs.
• It would allow the creation of new office markets in areas of large parcels along Townsend Street
adjacent to the railyards, and provide access within walking distance of Mission Bay biotech
• It would serve areas farther west with fewer residential uses than Folsom Street, thus making
them more appropriate for redevelopment to accommodate new employment uses.
• It would serve significant regional cultural and recreational areas such as AT&T Park and
Seawall Lot 337.
• It would make a connection to Caltrain and the T-Third/Central Subway lines at the station at
Fourth and King streets.
• It would accommodate a wider turnback from Market Street than the one to Folsom Street, and
thus would be easier to operate at normal BART speeds. Regardless of whether Folsom Street or
Townsend Street is chosen, the facilities should be designed for immediate integration into the
Market Street subway and the eventual extension serving the Van Ness and Geary corridors.
As part of the initial phase of this project, a BART terminal should be considered at a rebuilt Pier 36/38
facility, or elsewhere near the Embarcadero, which could later become a construction tie-in for the new
Recommendation 3.2 Extend SOMA line across the Bay as second Transbay Tube.
SPUR recommends extending the proposed SOMA subway line to the East Bay as part of a second
transbay tube. If the new tube accommodated a BART train, it would allow BART to reorient many of its
services based on travel demands. It could also provide access to areas currently unserved by regional rail.
MTC has developed two Bay Crossing Studies in the last 20 years. In addition, it has also produced a
Regional Rail Study in 2008. These studies explore a variety of options for new BART and standard-gauge tubes connecting San Francisco and the East Bay. SPUR believes it is a high regional priority to
carry these studies forward.
The most appealing option is a new 4-track tube that would include BART and commuter rail. The
addition of tracks for a commuter rail system increases the utility of the facility by allowing extension of
Caltrain service to the East Bay or Capitol Corridor service to San Francisco and the Peninsula. These
tracks would also facilitate the extension of High Speed Rail to the East Bay and elsewhere in California.
The San Francisco connection to the tube must, by law, be designed with track connections to the
Caltrain/High Speed level of the Transbay Transit Center’s rail level. This would allow Bay Area
commuters to not only travel to and from San Francisco, but also from San Francisco to Sacramento, San
Francisco Airport to Martinez, and Palo Alto to Berkeley. This is a critical project that enhances San
Francisco’s attractiveness as the center of the region and leaves the City with all the benefits of being on a
peninsula and none of the disadvantages.