UPDATE: The OB 29 has resumed its regular route through the area of Beverly and Holloway. https://t.co/h7vf1DxYJX (More: 11 in last 48 hours)

Central Subway Construction Update 12/9/16

Thank you for your interest in the Central Subway Project, which is a significant project in the history of San Francisco's public transportation network. This project is the first underground line to link the north and south corridors of the city, and will provide a direct connection to major retail, sporting and cultural venues while efficiently transporting people to jobs, educational opportunities and other amenities throughout San Francisco.

This is an exciting time as the San Francisco Municipal Transportation Agency's | Central Subway team works to construct a vital transportation link that, when open in 2019, will improve connectivity for the city. A group of holiday carolers braves the rain to sing and play instruments at the Winter Walk. Central Subway | Project Advancement

December 9 through December 18, 2016

This notice provides a construction update and a look ahead for what to expect in the areas where we are building four new stations along the alignment. You’ll find information about work activities, traffic and transportation impacts taking place over the next two weeks at SoMa, Yerba Buena|Moscone, Union Square and Chinatown.

Construction schedules, bus routes, and stop locations are subject to change due to unforeseen conditions. Signs will be posted at affected stops to advise of service changes.

Our thanks go out to the businesses, residents, shoppers, commuters, and all those who are touched by the Project, for their continued engagement as we work to extend the city's public transportation system.

The Central Subway Team

The east side of 4th between Townsend and Brannan is being restored and repaved. Surface Station, Trackwork and Systems Work along 4th Street between Bryant Street and King Street includes construction of a surface station between Bryant Street and Brannan Street. The construction team is upgrading utilities and trackwork on 4th Street between the tunnel portal at Bryant Street and the connection with the existing light rail system at King Street.

Night work is ongoing on 4th Street between Bryant and King Streets, between 8:00 PM and 5:00 AM.  Utility installation and upgrade work continues along 4th Street between Bryant and King, and regular day shift hours are from 7am to 4pm. Old utilities are removed to make way for new at the 4th and Townsend. A new sewer tie-in and manhole structure has been constructed at the 4th and Brannan intersection. Overview

  • Night work between King and Bryant
  • Sewer improvement work
  • Utility installation
  • Sewer manhole installation
  • Relocation of communication lines

Details

What: Night utility work between King and Bryant
Time: 8 p.m. - 5:00 a.m.
When: Monday to Saturday
Where: 4th Street between King and Bryant
What: Utility installation work

What: Pavement renovation
Time: 7 a.m. - 5:30 p.m.
When: Monday to Saturday
Where: 4th Street between King and Brannan

What: Installation of manhole structure, duct bank, utility installation
Time: 7 a.m. - 4 p.m.
When Monday to Friday
Where: 4th Street at Brannan

What: Relocation of communications lines
Time: 7 p.m. - 5 a.m.
When: Monday to Friday
Where: 4th Street at Brannan

What to expect

  • Work may involve saw-cutting, potholing and jack-hammering on the roadway and sidewalk
  • Sidewalk access may be limited
  • Access will remain open for pedestrians and businesses 
  • Parking and Traffic Impact
    • Partial lane closures on 4th Street between Townsend and King streets, including full closure of northbound 4th Street.
    • Detours will be in place. The crosswalk may be disrupted. Alternative pedestrian walkways will be in place.
    • Parking will be unavailable in the work area on both sides of 4th Street
    • Two lanes of traffic open on the west side of 4th Street
    • Traffic impacts are in effect 24 hours a day
  • Muni Impact
    • No scheduled impacts at this time.

The installation of temporary steel bracing has resumed inside the headhouse. Yerba Buena | Moscone Station

4th Street from Howard to Folsom

Work along 4th Street between Howard Street and Folsom Street consists of construction of the underground Yerba Buena | Moscone Station. The cut and cover method known as a "top-down" or "bottom-up" approach involves construction of a box frame structure within a trench excavation that is subsequently backfilled.

Excavation of the Yerba Buena/Moscone Station underneath 4th Street between Folsom and Clementina continues.  The current traffic configuration from north of the station to Howard Street will remain, but may change in the coming weeks.  Excavation and installation of temporary bracing continues at the station platform level.

A worker mixes cement as part of preparation work for eventual floor slab construction. Two workers coordinate welding on temporary bracing inside the station box. Overview

  • Excavation of the headhouse and station box and installation of temporary bracing
  • Roadway restoration on 4th south of Howard

Details

What: Excavation of the headhouse and station box and installation of temporary bracing
Time:  7a.m - 7p.m.
When: Monday to Friday
Where: 4th Street between Howard Street and Folsom Street

What: Roadway restoration on the east side of 4th Street south of Howard
Time:  7a.m.- 4p.m.
When: Monday to Friday
Where: 4th Street between Howard Street and Folsom Street What to expect

  • Clementina Street is closed at 4th Street
  • The sidewalk on the west side of 4th Street is closed
  • Parking and Traffic Impact
    • Two lanes of traffic open on 4th Street
    • Traffic configuration may be switched entirely to the east side of 4th in the coming weeks
  • Muni Impact
    • No scheduled impacts at this time

    Waterproofing is being installed at the bottom of the future north entrance at Union Square. Union Square | Market Street Station

    The 2016 Winter Walk is open!  Open for the holiday season, the 2016 Winter Walk stretches down Stockton between Geary and Ellis, complete with food trucks, entertainment, illuminated benches, and open space.  Some work continues at night along Stockton Street between Ellis Street and Post Street. The construction of an underground Union Square|Market Street Station uses the cut and cover method known as a "top-down" or "bottom-up" approach and involves construction of a box frame structure within a trench excavation that is subsequently backfilled.

    The installation of waterproofing and concrete at the southeast corner of the Union Square Garage continues.  There will be an increase in vehicles and activities at this location as work ramps up.  Station excavation and installation of temporary bracing is ongoing under Stockton Street as well as on O'Farrell.

    Shoppers and pedestrians enjoy the Off the Grid food trucks on Stockton Street, part of the 2016 Winter Walk. A crew conducts soil compacting and utility installation north of Geary on the west side of Stockton. Overview

    • Partial backfill work at the Ellis and Stockton intersection
    • Potential nighttime closure of Ellis and Stockton pedestrian crossing
    • Station excavation and installation of temporary bracing

    Details

    What: Potential nighttime closure of Ellis and Stockton pedestrian crossing
    Time: 10p.m. to 7a.m.
    When: 7 days a week
    Where: North side of the Ellis/Stockton intersection

    *For all activities, construction hours may be 24 hours a day, Monday to Saturday, Sunday work may be required What to expect

    • Sidewalk access may be limited at times
    • Parking and Traffic Impact
      • Stockton Street between Ellis Street and Geary Street is closed to vehicular traffic
    • Muni Impact
      • No scheduled impacts at this time.

    A worker tests a shotcrete-spraying machine inside one of the station cavern excavations called a side drift. Chinatown Station The construction of an underground Chinatown Station uses the sequential excavation method (SEM) along Washington Street and Stockton Street. The SEM provides a high degree of flexibility during construction and makes it possible to control virtually all kinds of ground conditions, thereby greatly reducing the risks of construction. This method of tunnel construction is used worldwide for small to large openings in a variety of ground types ranging from rock to soil.

    Sprayed concrete (shotcrete) and other supporting elements are applied and installed promptly after exposing ground, which provides a safe and stable opening.

    Current activities include excavation of the north and south platform caverns and completion of the primary concrete lining at the north access (emergency egress) shaft and tunnel.  The contractor completed barrel vault installation mid-November and then began breakout and excavation of the platform cavern side drifts.  PG&E may perform utility work at the Stockton/Washington intersection between 7pm and 6 am.

    As each of the side drifts are excavated, workers install steel reinforcing and spray shotcrete. A basket operator maneuvers a lift vehicle inside the station headhouse. Overview

    • Excavation of station site
    • Excavation of the north and south platform caverns
    • Complete primary lining of the north access (emergency egress) shaft and tunnel

    Details

    What: Excavation of station site
    Time: 24 hours
    When: Monday to Saturday
    Where: Stockton Street and Washington Street

    What: North access (emergency egress) shaft work
    Time: 7a.m.- 5p.m.
    When: Monday to Friday
    Where: Stockton Street, Washington Street to Jackson Street What to expect

    • Sidewalk access may be limited at times
    • PG&E may be performing night work from 7pm to 6am at Washington and Stockton, Monday through Saturday.
    • Parking and Traffic Impact
      • No parking on both sides of Stockton Street between Washington Street and Jackson Street
      • One lane of traffic on both sides of Stockton Street between Washington Street and Jackson Street
      • Washington Street:
        • remains closed between Stockton Street and Trenton Street
        • is converted into a two-way street between Powell Street and the construction zone
    • Muni Impact
      • No scheduled impacts at this time.

    Connecting People. Connecting Communities.

    Contact Us: If you have questions about construction or the Central Subway Project you can email us at central.subway@sfmta.com or leave a message at (415) 701-4371.

    For More Information: The Central Subway team posts frequent project updates on a variety of social media outlets. To find out more about the project and construction progress, follow us on Facebook, Twitter, or Flickr and check out our blog.

    Construction schedules are subject to change.