Construction Update
March 29 - April 7, 2014
During the next 10 days, Central Subway work will continue at sites in SoMa, Union Square, Chinatown and North Beach. This section contains brief updates about what is happening in each neighborhood. For more detailed information, scroll down or click on the links below. We also post construction, traffic detour and Muni impact information on our project Google Map.
Southern SoMa (Harrison to King/Berry): Potholing for utilities will continue next week on 4th Street between Bryant and King. A temporary walkway is in place around the construction zone. At the tunnel launch box on 4th Street between Harrison and Bryant, tunneling continues with both TBMs.
Northern SoMa (Market to Harrison): On 4th between Market and Stevenson and 4th Street between Folsom and Harrison, ground improvement work is now complete, and roadway restoration work is now underway. At 4th and Folsom, work to prepare for the Yerba Buena/Moscone Station continues. This will include soil test drilling at 4th and Folsom at night, as well as demolishing the roadway within the construction zone to prepare to construct underground station walls. This work will be noisy. Pavement restoration continues at the corner of 4th and Harrison Streets.
Union Square: Stockton Street between Ellis and Geary is closed to vehicular traffic to allow for construction of the Union Square/Market Street Station. Work is underway to excavate material before constructing station walls. Construction hours will be extended from 7 a.m. to 6 p.m.
Chinatown: The contractor will start station wall construction within the future station site and on the adjacent section of Washington Street.
North Beach: Work will continue at 1455 Stockton and 1731-1741 Powell. At 1731-1741 Powell, construction may be in progress this Saturday from 7 a.m. to 5 p.m. Sewer, roadway and sidewalk restoration on Columbus and Union will continue next week and is expected to be completed by the end of April. This Saturday, March 29, construction will be in progress from 7 a.m. to 5 p.m. Deliveries of concrete to the retrieval shaft is scheduled to begin at 3 a.m. on either April 1 or April 2.
We appreciate your patience and support while we build this essential upgrade to San Francisco's public transportation system.
-The Central Subway Team
Utility work is ongoing on 4th Street south of Bryant, where surface tracks will eventually be built.
Southern SoMa
4th Street from Harrison to King/Berry
On 4th Street between Harrison and Bryant streets, the contractor has constructed a major excavation known as a launch box at the site where the Central Subway tunnels begin. After assembly of two tunnel boring machines (TBM) underground, tunneling is underway, with operations based here.
On 4th Street between Bryant and King streets, potholing for utilities is now underway. Potholing involves drilling small holes and trenches in the street to confirm the locations of existing utility lines. More information is available in this construction notice.
Planned construction (Harrison to Bryant):
- Construct tunnel for southbound trains (TBM Mom Chung)
- Construct tunnel for northbound trains (TBM Big Alma)
- Sidewalk and roadway restoration on 4th and Harrison streets
Traffic and pedestrian impacts (Harrison to Bryant):
- The two lanes on the east side of the street (left lanes for southbound traffic) will remain open to vehicle traffic except as described below.
- The block may close to traffic from 8 p.m. to 5:30 a.m. on weeknights and all day Saturday and Sunday.
- The sidewalk on the west side of the block will remain closed; the sidewalk on the east side of the block will remain open.
- On Bryant Street at 5th Street, the left lane and several parking spaces will be closed.
- The bus stop located on Harrison and 4th streets will be relocated 150 feet west towards 5th Street.
- The sidewalk at Harrison and 4th streets may be closed during restoration.
Planned construction (Bryant to King):
- Potholing underway. Work will take place on 4th Street within construction zones marked by cones.
- Work may involve jack-hammering and cutting holes in the road. Please expect an increase in noise.
- Work hours will be Monday to Friday, 7 a.m. to 5 p.m.
- Removal of overhead wire on 4th Street between Welsh and Townsend.
- Install AT&T duct bank on the east side of 4th Street between Welsh and Bluxome.
Traffic and pedestrian impacts (Bryant to King):
- Temporary partial lane closures will be in effect on 4th Street in the vicinity of the construction zone.
- Parking will be impacted in the vicinity of the construction zone. The contractor will post 72-hour notification as required.
- Sidewalks may be impacted. The contractor will maintain a safe path of travel at all times.
- The contractor will maintain access to all businesses during business hours.
A backhoe removes the concrete walls of abandoned utilities on the site of the future Yerba Buena/Moscone Station. Northern SoMa
4th Street from Market to Harrison
On 4th Street between Market and Stevenson, roadway restoration is now in progress.
On 4th Street between Howard and Folsom, preparatory work to construct the Yerba Buena/Moscone Station is now in progress. Soil testing is underway and station construction will start soon.
On 4th Street between Folsom and Harrison, the contractor is restoring the area and will perform underground sewer surveys.
Planned construction (Market to Stevenson):
- Roadway restoration
Traffic and pedestrian impacts (Market to Stevenson):
- Two lanes of traffic will remain open on the west side of the street, with the work zone on the east side of the street (near Ross).
- The taxi stand has been relocated just south of Stevenson.
Planned construction (Howard to Folsom):
- Install shallow subsurface walls in preparation for station wall construction.
- Perform archeological and soil test drilling. Planned work hours are 7 p.m. to 5 a.m.
Traffic and pedestrian impacts (Howard to Folsom):
- The two right lanes of 4th Street will remain closed to traffic.
- Clementina between 4th and 5th is closed to thru traffic. Please use this block for local access only.
- The sidewalk on the west side of 4th Street between Clementina and Folsom will be closed. To ensure pedestrian safety, please cross at 4th and Howard and use the sidewalk on the east side of 4th street to reach Folsom.
- Big trucks will enter and exit the 4th and Folsom site during work hours. Flaggers will be on site to facilitate truck entry and exit.
- An additional lane closure between 9 p.m. until 5 a.m. will occur on 4th Street between Howard and Folsom.
Planned construction (Folsom to Harrison):
- Restoration of the roadway.
Traffic and pedestrian impacts (Folsom to Harrison):
- On 4th Street the parking lane on the eastern side of the street will be closed for pavement restoration. The parking lane and one traffic lane on the western side will be closed for pavement restoration.
- On Harrison Street, one lane may be closed to allow for work in the intersection of 4th and Harrison.
These curved forms are used to help machinery stay aligned while drilling out abandoned utilities.
Union Square
Stockton Street from Market to Post
On Stockton Street between Ellis and Geary, contractor Tutor Perini is building the Union Square/Market Street Station. Preparatory construction is now in progress, with the roadway closed to vehicle traffic.
Ground improvement related to tunneling is now complete on Ellis Street between Stockton and Powell streets. The tunnel contractor is restoring the site and will vacate soon. Ellis Street will remain as a construction zone for the station contractor.
Planned construction (Stockton Street from Ellis to Maiden Lane):
- Demolish roadway and underground walls. This work, which involves breaking and removing the roadway pavement, will be noisy.
- Potholing for utilities at Stockton and O’Farrell, and Stockton and Geary will occur in the evening.
- Installing guide walls for pile installation.
- Construction hours will be extended. Hours will usually be Monday to Friday, 7 a.m. to 6 p.m., with weekend work required at times.
- Installing piles to construct station walls.
Planned construction (Ellis Street):
- The tunnel contractor is backfilling the shaft and restoring the area. Ellis Street will remain as a construction zone for the station contractor.
Planned construction (Stockton Street from Sutter to Clay):
- No construction planned
Traffic, transit and pedestrian impacts:
- Stockton Street between Ellis and Geary is closed to vehicular traffic
- Sidewalks will remain open, but they will be narrowed.
- Ellis Street between Stockton and the Ellis-O'Farrell Garage (between Stockton and Powell) will remain closed to westbound traffic.
- The parking lane and one lane of traffic on the eastern side of the street will be closed between Post and Geary.
More information about construction at this site is available in this construction notice. 
In Chinatown, we have begun to excavate soil where underground walls will be built.
Chinatown
Stockton Street from Sacramento to Broadway
On Stockton Street from Sacramento to Broadway, construction of Chinatown Station is now underway within the property lines and nearby on Washington Street.
Planned construction:
- Construct station walls.
- Construction hours are Monday to Saturday, 7a.m. to 7p.m.
- Drill observation wells on Stockton between Clay and Jackson, on Clay near Stockton, on Washington between Stockton and Powell.
- NIGHT WORK: Observation wells will be drilled on Washington between Stockton and Powell. Night work hours are 8p.m. – 4a.m.
Traffic, transit and pedestrian impacts:
- Washington Street between Stockton and Trenton will remain closed to vehicles and pedestrians
- Washington Street between Powell and the construction zone has been converted into a two-way street.
- To ensure safety, please obey all traffic and pedestrian signs in the area.
- The parking lanes along Washington Street and Clay Street adjacent to Stockton Street may be closed during construction hours.
- The parking lanes along Stockton between Clay and Jackson may be closed during construction hours.
At the tunnel boring machine retrieval shaft, these temporary cross-braces will be left in place until the reinforced concrete floor slab is poured.
North Beach
Powell Street from Union to Columbus
On private property at 1731-1741 Powell Street, the contractor is building a walled excavation known as a retrieval shaft at the site where tunneling will end. The two tunnel boring machines will be removed from the ground here. We plan to complete work at this location in 2014.
On private property at 1455 Stockton Street, the contractor is constructing an underground shaft to perform ground improvements when the TBMs pass below Columbus Avenue.
On Columbus Avenue near the intersection with Union Street, crews are completing underground sewer work and restoring the roadway and sidewalk.
Planned construction (1731-1741 Powell):
- Excavate retrieval shaft and install bracing
- Construction hours are Monday to Saturday, 6 a.m. to 8 p.m.
- This Saturday, March 29, construction will be in progress from 7 a.m. to 5 p.m.
- Deliveries of concrete to the retrieval shaft is scheduled to begin at 3 a.m. on either April 1 or April 2.
Traffic, transit and pedestrian impacts (1731-1741 Powell):
- Several parking spaces may be closed in front of the property.
- The sidewalk in front of the property may be closed. A temporary walkway will be in place around the construction zone when the sidewalk is closed.
Planned construction (1455 Stockton):
- Ground improvement related to tunneling will be performed as the TBMs pass below in the next few months.
Traffic, transit and pedestrian impacts (1455 Stockton):
- No impacts to traffic, transit or pedestrian walkways are anticipated.
- The parking lot at 1455 Stockton will remain closed.
Planned construction (Columbus and Union):
- Sewer, roadway and sidewalk restoration.
- Construction hours are Monday to Friday, 9a.m. to 3p.m.
Traffic, transit and pedestrian impacts (Columbus and Union):
- On Columbus between Union and Filbert, the left lane for northbound traffic will be closed during construction hours.
- The northbound bus stop on Columbus at Union will remain open, but it will be temporarily relocated about 100 feet to the north during construction hours.
Central Subway Construction Fast Facts
Project Alignment: 4th Street between Berry and Market streets; Stockton Street between Market Street and Columbus Avenue; Powell Street between Union Street and Columbus Avenue; Columbus Avenue between Powell and Filbert streets.
Transit Reroutes: The southbound 8X/8AX/8BX Bayshore Express, 30 Stockton, 45 Union/Stockton and 91 Owl Muni bus routes have been rerouted to accommodate construction in Union Square and SoMa. These reroutes will remain in effect throughout the duration of Central Subway construction. More information is available online here.
Contact Us: Should you have questions about construction or the Central Subway Project, don't hesitate to contact our team. You can reach us at central.subway@sfmta.com or by phone 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, Instagram or Flickr, and check out our blog.
Construction schedules are subject to change.