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/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 San Francisco Municipal Transportation Agency 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 District, and other neighborhoods in the northern portion of San Francisco.

Project Timeline 
Concept Feasibility Study 2015
T Third Extension Concept Study
Completed
Alternatives Study 2018-2019
Central Subway Extension Planning & Outreach
Pending
Environmental Review
Study enviromental impacts of the project
Pending
Design/Engineering
Design project
Pending
Construction
Build the Central Subway Extension
Pending
Current Phase or Stage 
Planning / Outreach
Project Status 
Planning
Improvements 
SFMTA Muni Metro train icon
Extending the T-Third to North Beach, Fisherman's Wharf and other destinations in northern San Francisco
Streets 
Powell Street, Columbus Avenue, Jefferson Street

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/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/Brannan (surface), Moscone Center (underground), and Market Street/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 approximately one additional mile north of the Chinatown Station, to Columbus and Powell Streets in North Beach.  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, so as to minimize surface disruption.  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.

Project Details, History or Features 

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 in 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 a remaining handful 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:

  • Step 1) Surveying community organizations in small groups to determine the desirability of a subway extension, transportation goals for the project, along with any desired route and station locations (Spring-Summer 2018) 
    • The SFMTA will use this input to develop a preliminary set of alternatives that meet the identified goals
  • Step 2) Presenting the preliminary set of alternatives at community meetings, to confirm that the alternatives address the goals identified in Step 1, and to make refinements (Fall-Winter 2018)
    • 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.
  • Step 3) Sharing the draft Alternatives Study report results at community meetings, to seek input on preferred alternatives and gather feedback (Mid-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.
  • Step 4) Issuing the final version of the study

 

Contact Information 
Kansai Uchida, Project Manager
415.646.2632
Lulu Feliciano, Outreach Manager
415.701.4453
Adrienne Heim, Public Information Officer
415.646.2564