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. 
Ongoing 78' sewer work along 4th Street between Brannan and Townsend Central Subway | Project Advancement
June 12 - June 22, 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
Reinforced concrete sewer roof is moving forward 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 tunnel portal at Bryant and the connection with the existing system at King Street.
Major construction activities will occur at the 4th and King intersection, where special trackwork will be installed to connect the existing and new rail systems. This work will be scheduled on three-day holiday weekends, with vehicle traffic maintained or detoured during that time.
Current activity on 4th Street are utilities relocation, Muni manhole, duct bank installation and sidewalk restoration.
June 8-July 3, the contractor is performing work on the 36' sewer line at the 4th and King streets intersection between the hours of 9a.m. to 3p.m. No through-traffic available on King Street to I-280. For more information, please see this notice. 
Installation of the 36' sewer line begins on 4th between Townsend and King streets 
Installation of sewer line on 4th Street between Brannan to Townsend Overview
- Installation of Muni manhole and duct bank
- Utility installation
- Sidewalk restoration
- 36' sewer line
Details
What: Installation of Muni manhole, duct bank, utility installation and sidewalk restoration
Time: 7a.m.-4p.m.
When: Monday to Friday
Where: Brannan to King ; 4th and Bryant
What: 36' sewer line
Time: 9a.m.-3p.m.
When: Monday to Friday
Where: Intersection at 4th and King What to expect
- Work may involve saw-cutting, potholing and jack-hammering on the roadway and sidewalk
- Sidewalk access may be limited
- The contractor will maintain a safe path of travel as well as access to businesses during business hours
- Parking and Traffic Impact
- Parking will be unavailable in the work area
- Two lanes on 4th Street between Bryant and King streets are available for traffic
Concrete setting for water-proofing installation of the roof deck on the east side of 4th Street for the future Yerba Buena | Moscone Station Yerba Buena | Moscone Station
4th Street from Howard to Folsom
Work along 4th Street between Howard and Folsom streets consists of constructing 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.
You can expect utility relocation, traffic re-routing, noise, dust, and traffic, transit and business access disruption.
Current activity includes excavation, roof deck installation and utility relocation.
Concrete pour for the roof deck on the east side 
Excavation continues on the west side of the Yerba Buena | Moscone Station Overview
- Installation of utilities
- Excavation and installation of the roof deck
Details
What: Excavation and roof deck installation
Time: 7a.m.-7p.m.
When: Monday to Friday
Where: Howard to Folsom
What: Utility night work
Time: Folsom Street work begins at 9p.m.-5a.m.; Howard Street work begins 6p.m.-5a.m.
When: Monday to Friday
Where: 4th and Folsom and 4th and Howard What to expect
- Clementina Street is closed at 4th Street
- The sidewalk on the west side 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
Demolition of the Union Square Garage continues 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.
You can expect utility relocation, traffic re-routing, noise, dust, and traffic, transit and business access disruption.
Current activity includes roof deck installation, demolition of the Union Square Garage, utility relocation and compensation and jet grouting.
Roof beams installation on Ellis Street 
A view from underneath the roof beams Overview
- Installation of roof deck
- Utility relocation and support
- Excavation
- Compensation and jet grouting
- Demolition of Union Square Garage
Details
Time: 7a.m.-7p.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 August
- O'Farrell Street will be narrowed to one lane at Stockton Street until late July
- Stockton Street between Ellis and Post streets is closed to vehicular traffic
Roof deck has been completed Chinatown Station The construction of an underground Chinatown Station uses the sequential excavation method (SEM) along Washington 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.
Utility relocation, traffic re-routing, and transit impacts on Stockton Street is expected as work continues between Sacramento and Jackson.
Mid week of June 15, the crosswalk on the west side of Stockton and Washington streets will be closed due to a manhole installation within the site. 
A view of the work progressing at the future Chinatown Station 
Roof deck poured Overview
- Potholing for dewatering wells
- PG&E reconstructing underground utilities
- Instrumentation installation
- Waterproofing, backfilling and excavation of station site
Details
What: Potholing for dewatering wells
Time: 7a.m. to 5p.m.
When: Monday to Friday
Where: Washington and Jackson
What: PG&E activity
Time: 9a.m. to 3p.m. and 7a.m. to 6p.m.
When: Monday to Friday and Saturday
Where: Washington and Jackson
What: Instrumentation night work
Time: 9p.m. to 5a.m.
When: Monday to Friday
Where: Sacramento to Jackson
What: Waterproofing, backfilling and excavation
Time: 7a.m.-7p.m.
When: Monday to Saturday
Where: Stockton and Washington What to expect
- Sidewalk access may be limited at times
- Muni Service Impact
- A bus stop for southbound 8/8AX/8BX Bayshore Express, 30 Stockton, 45 Union/Stockton and 91 Owl on Stockton Street between Washington and Jackson streets is relocated to the north of Jackson Street on Stockton Street
- Parking and Traffic Impact
- Parking will be unavailable during PG&E, water line and potholing work
- Parking may be limited during instrumentation installation
- Washington Street:
- remains closed between Stockton 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, or Flickr, and check out our blog.
Construction schedules are subject to change.