Central Subway Extension
The Central Subway project, planned to open in late 2019, will serve over 35,000 new customers per day. It will bring the T Third Street light rail line from its existing 4th and King Station into a new subway running beneath 4th and Stockton Streets, terminating at Chinatown Station (Washington and Stockton Streets). This new service will connect residents, visitors and businesses from Bayview, South of Market, Mission Bay to Financial District, Union Square, Moscone Center, and Chinatown. As the Central Subway nears completion, the San Francisco Municipal Transportation Agency (SFMTA) is looking ahead at opportunities to extend subway service beyond Chinatown. The City is projected to grow to nearly 1,000,000 residents by 2040. The need for efficient public transit is great today and will continue to grow in the future.
The Central Subway Extension is an opportunity for the SFMTA to evaluate a potential extension of the under construction Central Subway beyond its current Chinatown Station terminal. Possible destinations include North Beach, Fisherman’s Wharf, the Marina, Cow Hollow, and Presidio.
Reasons for Studying the Central Subway Extension
In 2019, the Central Subway (Third Street Light Rail Phase 2) will open for passenger service, bringing the T Third Street light rail line from its existing 4th and King Station into a new subway running beneath 4th and Stockton Streets, terminating at Chinatown Station (Washington and Stockton streets). In addition to the underground Chinatown Station, new stations will also be located at 4th and Brannan (surface), Moscone Center (underground), and Market Street and Union Square (underground). For more information about the Central Subway project.
Although the Chinatown Station will be the northern terminal of the Central Subway when it opens in 2019, the subway tunnels presently extend north of the Chinatown Station, to Columbus and Powell Streets in North Beach. In order to minimize surface disruption, these additional tunnels were constructed so that the tunnel boring machines (TBMs) used during project construction could be removed from the ground in an area where off-street space was available. Though no passenger service will be operated in the tunnels north of Chinatown Station when the Central Subway opens, the tunnels are designed to allow the line to be extended further to the north and/or west in the future.
Given that a substantial investment has already been made in the form of subway tunnels extending as far north as Columbus and Powell, the SFMTA is studying the potential to add a station in the existing tunnels in North Beach, and possibly extend the subway further to the north and/or west.
Prior Work: 2015 Concept Study
Background of the concept study
The Concept Study was a joint effort between the San Francisco County Transportation Authority (SFCTA), the San Francisco Municipal Transportation Agency (SFMTA), and the San Francisco Planning Department, with SFMTA as the lead agency. The final version of the Concept Study was completed in January 2015.
The Concept Study identified preliminary technical strengths and tradeoffs of sample subway extension routes along Powell Street, Beach Street, and Columbus Avenue for consideration by stakeholders, governing bodies, and the public. The study evaluated the sample alternatives based on criteria including:
- Passenger Experience
- Operational Efficiency
- System Performance
- Local Operations Considerations
- Infrastructure Resiliency
- Construction Effects
- Capital Construction Costs
Current Phase: Alternatives Study:
- Building upon the 2015 Concept Study, the Alternatives Study is the next phase of the planning process, which the SFMTA is beginning in Spring 2018 and expects to complete by mid-2019. The Alternatives Study will combine community input with concept-level engineering to identify viable project alternatives (potential routes and station locations). The primary goal of the study is to evaluate and screen the alternatives based on community feedback and engineering feasibility, resulting in two to three of the most promising alternatives. Depending on community support for the project and the availability of funding, these alternatives would be carried forward for environmental review in a future phase of the project.
- During the Alternatives Study, the project team will conduct a variety of activities to engage and gather feedback; from stakeholder interviews to workshops and other interactive activities. This community participation effort will be conducted in three distinct steps:
Survey community organizations to determine the desirability of a subway extension, transportation goals for the project, along with any desired route and station locations (summer 2018 to winter 2019).
- The SFMTA will use this input to develop a preliminary set of alternatives that meet the identified goals
Present the preliminary set of alternatives at community meetings, to confirm that the alternatives address the goals identified in Step 1, and to make refinements (winter to spring 2019).
- The SFMTA will take the refined alternatives and perform concept-level analysis (developing preliminary plan drawings, cost estimates, and cost/benefit analyses), and prepare a draft Alternatives Study report summarizing the results.
Share the draft Alternatives Study report results at community meetings, to seek input on preferred alternatives and gather feedback (summer 2019).
- The SFMTA will document the feedback and prepare a final version of the Alternatives Study report. The preferred alternatives will undergo environmental review during a future phase of the project, contingent upon community support for the project and funding availability.
- Circulate the final version of the study.