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. 
An excavator removes debris from the southeast section of Union Square Garage
Central Subway | Project Advancement
February 5, 2016 - February 15, 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
Utility work is ongoing at 4th Street and Bryant Street
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 portal at Bryant Street and the connection with the existing system at King Street.
Current activities include utilities relocation, Muni manhole, duct bank, water line work from the water department, auxiliary water supply system (AWSS), sewer structure modification work and overhead catenary system (OCS) pole foundation work.
Installation of a 36" sewer line at the intersection of 4th Street and Townsend Street continues through March. Hours of construction are 7p.m. to 5a.m.
A worker covers a trench where utility work is being performed at 4th Street and Freelon Street
Potholing and utility relocation are being performed on 4th Street and Brannan Street Overview
- Installation of Muni manhole and duct bank
- Utility installation
- Installation of AWSS
- OCS pole foundation work
- Installation of 36' sewer line
Details
What: Installation of Muni manhole, duct bank, utility installation
Time: 7a.m.- 4p.m.
When: Monday to Friday
Where: Brannan Street between 4th Street and 5th Street, Townsend Street to King Street
What: Installation of AWSS
Time: 7a.m.- 4p.m.
When: Monday to Friday
Where: 4th Street between Brannan Street and Townsend Street and 4th Street between Brannan Street and Bluxome Street
What: OCS pole foundation installation
Time: 7a.m. - 4p.m.
When: Monday to Friday
Where: 4th Street between Bryant Street and Townsend Street
What: Installation of 36" sewer line (night work)
Time: 7p.m. - 5a.m.
When: Monday to Friday
Where: Intersection of 4th Street and Townsend Street
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
- Parking will be unavailable in the work area along 4th Street
- Muni Impact
- 30 Stockton and 45 Stockton|Union bus stop will be relocated 100 feet west of 4th Street and Townsend Street during night work sewer installation
A bulldozer operator removes mud from the station box 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 for the new station is currently taking place.
A welder works on steel panels at the Yerba Buena | Moscone site 
An excavator removes material from the station box under 4th Street Overview
- Excavation
Details
What: Excavation
Time: 7a.m.-7p.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 the east side of 4th Street
Excavation in preparation to inslall the roof deck continues on Stockton Street, south of O'Farrell Street Union Square | Market Street Station
For the duration of the project, you'll see work 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.
Current activities include roof deck installation, demolition of the southeast corner of the Union Square Garage, compensation and jet grouting, and utility relocation.
Utility work is ongoing on Stockton Street between Geary Street and Maiden Lane
Removing rebar from the demolished southeast corner of the Union Square Garage Overview
- Installation of roof deck
- Utility relocation and support
- Excavation at north concourse
- Partial demolition and remodeling of Union Square Garage
- Rebar installation
- Concrete installation as roadway backfill at north and south concourses
Details
What: Roof deck, utility, excavation, rebar installation, partial demolition of Union Square Garage and concrete installation
Time: 7a.m.-11p.m.
When: Monday to Saturday
Where: Ellis Street to Post Street
* Construction hours may be 24 hours a day, Monday to Saturday, Sunday work may be required What to expect
- Local deliveries may access Maiden Lane from Post Street
- Sidewalk access may be limited at times
- Parking and Traffic Impact
- Although Ellis Street is reopened to one lane of eastbound traffic, vehicles will not be able to turn onto Market Street as part of the Safer Market Street project. For more information, please visit https://www.sfmta.com/projects-planning/projects/safer-market-street
- Stockton Street between Ellis Street and Post Street is closed to vehicular traffic
Workers use wood and rebar to form the arched entrance to the station 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 immediately after exposure, followed by installation of additional steel and shotcrete support elements until a safe stable opening is created will be used.
Current activities include utility relocation, excavation of the headhouse, north access (emergency exit) shaft construction and sewer upgrades. 
A view of the headhouse from street level 
Workers assemble a rebar cage that will be part of an interior wall Overview
- Excavation of station site
Details
What: Excavation of station site
Time: 24 hours
When: Monday to Saturday
Where: Stockton Street and Washington Street
What to expect
- Sidewalk access may be limited at times
- Parking and Traffic Impact
- No parking 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
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 call us 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, and Flickr.
Construction schedules are subject to change.