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. 
Finishing out a wall of the Union Square I Market Street station on the east side of Stockton Central Subway | Project Advancement
September 11 - September 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 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
Trenching and utility upgrades are ongoing on 4th Street Surface Station, Trackwork and Systems For the work along 4th Street between Bryant and King streets, a surface station located between Bryant and Brannan Streets will be built. Besides construction of the surface station, the only visible construction activities will be upgrading utilities and trackwork on 4th Street between the portal at Bryant and the connection with the existing system at King Street.
Current activities include utilities relocation, Muni manhole and duct bank installation. 
Workers survey the construction zone across from the Caltrain Station
Work to install and upgrade utilities is ongoing Overview
- Installation of Muni manhole and duct bank
- Utility installation
Details
What: Installation of Muni manhole, duct bank, utility installation
Time: 7a.m. - 4p.m.
When: Monday to Friday
Where: Brannan Street between 4th and 5th, Townsend to King
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 along the work area
Work on the station roof is in progress Yerba Buena | Moscone Station
4th Street from Howard to Folsom
Work along 4th Street between Howard and Folsom streets 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.
Take note: Howard Street between 3rd and 4th Street is closed from 8:00p.m. Thursday, September 10 through Sunday, September 20 at 3:00p.m. due to the Dreamforce event at the Moscone Center. On both 3rd and 4th streets, one lane of traffic will be closed during this time.
Current activities include utility relocation and excavation.
Scaffolding which will be used to access the headhouse interior is being constructed and will be lowered into the site at a later time 
Trenching operations continue at the site of the future Yerba Buena | Moscone station site Overview
- Installation of utilities
- Excavation
Details
What: Utility night work
Time: Folsom Street work begins at 9p.m.-5 a.m, Howard Street work begins 6p.m.-5a.m.
When: Monday to Friday
Where: 4th and Folsom and 4th and Howard
What: Excavation
Time: 7a.m.-7p.m.
When: Monday to Friday
Where: Howard to Folsom
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
- One lane will be available on the west side of 4th Street
- Two right lanes on Folsom Street available during night work
- Howard Street between 3rd and 4th Streets closed through 3p.m. September 20. This includes one traffic lane on both 3rd and 4th Streets
Worker welds short I-beam sections to the floor slab of the Union Square | Market Street station Union Square | Market Street Station
For the duration of the project, you'll see work along Stockton Street between Ellis and Post streets. 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.
Current activities include roof deck installation, demolition of the northwest corner of the Union Square Garage, utility relocation, compensation, and jet grouting.
Single-lane traffic continues through early October on Geary at Stockton for pile installation. Take note: Geary and Stockton intersection to close weekend of September 11 through mid-week the week of September 14.
Work to excavate the site to construct interior structural elements and the floor slab is underway at the intersection of Ellis and Stockton 
Stairs from the former Ellis Street/Powell entrance of the BART/Muni station is visible amid structural beams and piles at the new south concourse of the Union Square | Market Street station. Overview
- Installation of roof deck
- Utility relocation and support
- Excavation
- Compensation and jet grouting
- Partial demolition of Union Square Garage
- Rebar installation
Details
What: Roof deck, utility, excavation, compensation and jet grouting, rebar installation and partial demolition of Union Square Garage
Time: 7a.m.-11p.m.
When: Monday to Saturday
Where: Ellis to Post
* 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
- Muni Service Impact
- The bus stop for the 38 Geary Route on Geary Boulevard at Stockton Street is discontinued until further notice. Board bus on Geary Boulevard at Powell Street.
- Parking and Traffic Impact
- Ellis Street is closed to through traffic between Stockton and mid-block until late September
- Stockton Street between Ellis and Post streets is closed to vehicular traffic
- Geary and Stockton intersection night closure expected the weekend of September 11 through mid-week the week of September 14
Sparks fly as steel worker cleans up edge of a steel plate Chinatown Station The construction of an underground Chinatown Station uses the sequential excavation method (SEM) along Washington and Stockton Streets. 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, and dewatering wells.
Dewatering wells installation on Stockton Street from Sacramento to Jackson streets continues through October. 
An excavator operator uses the long arm of the excavator to remove soil from the headhouse exterior 
Light flashes and sparks fly with welding and torch cutting above the temporary steel supports Overview
- Excavation of station site
- Installation of dewatering wells
- Drilling of compensation grout holes from inside the headhouse
- Relocation of existing utilities
- Installation of instrumentation monitoring units
Details
What: Excavation of station site and drilling compensation grout
Time: 7a.m.- 7p.m.
When: Monday to Saturday
Where: Stockton and Washington
What: Dewatering wells installation
Time: 9p.m.- 5a.m.
When: Monday to Friday
Where: Washington to Jackson
What: Relocation of existing utilities
Time: 7a.m -7p.m.
When: Monday to Friday
Where: Stockton, Washington to Jackson
What: Installation of instrumentation monitoring units
Time: 9p.m.-5a.m.
When: Monday to Saturday
Where: Stockton, Sacramento to Jackson
What to expect
- Sidewalk access may be limited at times
- Parking and Traffic Impact
- Detour will be in place between the hours of 9p.m. to 5a.m. during dewatering wells installation
- Parking will be unavailable during PG&E 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.