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 worker inspects equipment on the west side of the Chinatown station headhouse where efforts to construct the first portions of the final interior structure have begun
Central Subway | Project Advancement
December 11 - 21, 2015
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 goes 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
Auger bits restored on 4th north of Freelon while two workers coordindate the movement of a backhoe out of the work site.
Surface Station, Trackwork and Systems For the work along 4th Street between Bryant and King streets, a surface station will be built between Bryant and Brannan Streets. The construction team is working on 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, and sewer structure modification work. 
A lane of traffic has been closed on the west side of 4th between Brannan and Townsend for utility work to commence here
Equipment is temporarily stored on 4th south of Brannan Overview
- Installation of Muni manhole and duct bank
- Utility installation
- Installation of high pressure water lines
- Tunnel drainage and invert slab construction
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: Low pressure water line/AWSS
Time: 7a.m. - 4p.m.
When: Monday to Friday
Where: 4th Street between Welsh Street and Brannan Street
What: Installation of 8" waterline
Time: 9p.m. - 5a.m.
When: Monday to Friday
Where: 4th Street and Brannan Street
What: High pressure waterline
Time: 9p.m. - 5a.m.
When: Monday to Friday
Where: 4th Street south of Townsend
What: Tunnel drainage and invert slab construction
Time: 7a.m. - 4p.m.
When: Monday to Friday
Where: 4th Street Tunnel
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
- Muni Impact
- 4th Street and Bryant Street bus stop relocated 250 feet off the intersection affecting 8 Bayshore, 8AX Bayshore Express, 8 BX Bayshore Express and 47 Van Ness bus lines.
- Parking and Traffic Impact
- Parking will be unavailable along the work area
- One lane on 4th Street closed during nightwork
Workers coordinate the lifting and carrying of rebar sections to ensure a smooth workflow. 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.
Currently, excavation is taking place.
Steel plates used for reinforcing during concrete pours wait on 4th Street to be lowered into place inside the station box 
A worker looks over the sheet pile wall into the headhouse site where rebar is being lowered near the station box portal Overview
- Excavation
Details
What: Excavation
Time: 7a.m.-7p.m.
When: Monday to Friday
Where: Howard Street to 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
Ellis Street through Stockton and Market is temporarily open for the holiday season 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 involves construction of a box frame structure within a trench excavation that is subsequently backfilled.
There will be limited daytime activities throughout the moratorium, limited to spaces north of Geary and at Ellis Street. Single-lane traffic continues until the construction moratorium begins on Geary at Stockton or until street restoration north of Geary is complete.
Winter Walk 2015 opened to the public November 27 and runs through January 1. For more information, click here.
Shoppers enjoying the Winter Walk 
Decorative banners welcome shoppers and pedestrians to the bustling green turf areas of the Winter Walk where food trucks are stationed four days a week Overview
- Installation of roof deck
- Utility relocation and support
- Excavation at north concourse
- Partial demolition and remodeling of Union Square Garage
- Rebar installation
- Lightweight 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 lightweight 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
During excavation, several cast iron sewing machine stands likely buried in the 1906 earthquake and fire 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, trenching and connection of dewatering wells, north access (emergency exit) shaft construction and sewer upgrades.
Archaeologists from Sonoma State University examine relics found in the excavation area. Work to excavate the shaft is paused. 
View of the north access shaft site, looking south down Stockton near Washington Overview
- Excavation of station site
- Connection of dewatering wells
- Installation of temp bracing
- North access (emergency exit) shaft construction
- Sewer upgrades
Details
What: Excavation of station site
Time: 7a.m.- 7p.m.
When: Monday to Saturday
Where: Stockton Street and Washington Street
What: Connection of dewatering wells
Time: 7a.m -5p.m.
When: Monday to Friday
Where: Stockton Street, Sacramento Street to Jackson Street
What: Installation of temp bracing
Time: 7a.m -5p.m.
When: Monday to Friday
Where: Stockton Street
What: North access (emergency exit) shaft construction
Time: 7a.m -5p.m.
When: Monday to Friday
Where: Stockton Street, Washington to Jackson Street
What: Sewer upgrades
Time: 7p.m -5a.m.
When: Monday to Friday
Where: Stockton Street, Clay to Washington Street
What to expect
- Sidewalk access may be limited at times
- Parking and Traffic Impact
- Detours will be in place between the hours of 9p.m.and 5a.m. during north access shaft construction
- Parking will be unavailable during PG&E work
- No parking on both sides of Stockton between Washington and Jackson
- No parking on both sides of Stockton between Clay and Washington during night work
- Washington Street:
- remains closed between Stockton and Trenton streets
- 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, or Flickr, and check out our blog.
Construction schedules are subject to change.