Construction Update
January 25-February 3, 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): We plan to begin potholing for utilities on 4th Street between Bryant and King next week, on Monday, Jan. 27. Potholing will commence on the east side of 4th Street between Bryant and Bluxome, proceeding at other locations along the block over the coming months. More details are in the Southern SoMa section. At the tunnel launch box on 4th Street between Harrison and Bryant, tunneling continues with both TBMs.
Northern SoMa (Market to Harrison): Construction will continue on 4th between Market and Stevenson next week and this weekend (Jan. 25-26) as the second TBM passes through the area. On 4th Street between Folsom and Harrison, the road expected to reopen in February. At 4th and Folsom, work to prepare for the Yerba Buena/Moscone Station continues. Work may include demolishing the roadway within the construction zone to prepare to construct underground station walls. This work will be noisy.
Union Square: Stockton Street between Ellis and Geary is closed to vehicular traffic to allow for construction of the Union Square/Market Street Station. On Ellis Street, crews may work through the weekend to prepare for the crossing of the second TBM under Market Street. On Stockton Street, crews will work on Saturday installing barricades around the construction zone.
Chinatown: Work to prepare for the Chinatown Station continues within the future station site and on the adjacent section of Washington Street.
North Beach: Work on Columbus Avenue at Union Street will continue next week, Monday to Friday. Work will continue at 1455 Stockton and 1731-1741 Powell, within the property lines. At 1731-1741 Powell, construction may be in progress on Saturdays from 7 a.m. to 5 p.m.
We appreciate your patience and support while we build this essential upgrade to San Francisco's public transportation system.
-The Central Subway Team 
TBM Mom Chung has reached the foundations of Nob Hill under Stockton and Post. These rocks are bedrock, chopped up by the machine as it moves ahead. 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, we plan to begin potholing for utilities the week of Jan. 27. 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)
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.
Planned construction (Bryant to King):
- Potholing is planned to start on 4th Street between Bryant and Bluxome the week of Jan. 27
- Work will take place on the eastern side of 4th Street and the eastern sidewalk, within construction zones marked by cones
- Work hours will be Monday to Friday, 7 a.m. to 5 p.m.
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.
Construction continues at the site of the future Yerba Buena/Moscone Station, seen from above in this image. Northern SoMa
4th Street from Market to Harrison
On 4th Street between Market and Stevenson, construction has resumed and will continue for approximately two weeks as the second TBM passes through the area.
On 4th Street between Howard and Folsom, preparatory work to construct the Yerba Buena/Moscone Station is now in progress at the corner of 4th and Folsom. Station construction will start soon.
On 4th Street between Folsom and Harrison, the contractor will restore the area and perform underground sewer surveys. We expect work at this location to be completed in February.
Planned construction (Market to Stevenson):
- Perform ground improvements as needed. Crews may be on site throughout the night next week while tunneling is underway in this area.
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 test elements for underground walls
- Install shallow subsurface walls in preparation for station wall construction
- Investigate archeological conditions
- Planned work hours are Monday to Friday, 7 a.m. to 5 p.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 use the sidewalk on the east side of the street and cross at 4th and Howard.
- 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.
Planned construction (Folsom to Harrison):
- No work planned next week
Traffic and pedestrian impacts (Folsom to Harrison):
- North of Clara Street, the parking lane and one lane of traffic on the eastern side of the street will be closed
- South of Clara Street, the parking lane and one center lane will be closed to allow for work in the intersection of 4th and Harrison
Seen from above, crews have started breaking the pavement of Stockton Street, preparing to build the Union Square/Market Street Station. 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 will be in progress on Ellis Street between Stockton and Powell streets. This work should be completed in early February, with site restoration following.
Planned construction (Stockton Street):
- Install barricades around construction zone on Stockton between Ellis and O'Farrell. Construction will be in progress on Saturday, Jan. 25.
- Demolish roadway and underground walls. This work, which involves breaking and removing the roadway pavement, will be noisy.
- Tentative: Pothole for utilities.
- Regular work hours are Monday-Friday, 7 a.m. to 5 p.m., with evening and weekend work required at times
Planned construction (Ellis Street):
- Perform ground improvements related to tunneling. Crews may be on site throughout the night next week while tunneling is underway in this area.
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
More information about construction at this site is available in this construction notice. 
At the Chinatown Station site, we have built these shallow walls around the perimeter of the station location. They'll serve as a guide for the machines building the deeper station walls. Chinatown
Stockton Street from Sacramento to Broadway
To prepare to build the Chinatown Station, contractor Tutor Perini has demolished the existing building at 933-949 Stockton Street. Construction is now underway within the property lines and nearby on Washington Street and Stockton Street.
Planned construction:
- Perform utility work on Washington Street within the construction zone
- Mobilize construction equipment
- Construct shallow subsurface walls in preparation for station wall construction
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 lane on Clay and Washington streets adjacent to Stockton Street may be closed during construction hours
Utility work has recommenced on Columbus Avenue, continuing on weekdays for about a month. 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 will be completing underground sewer work, starting next week. This work is expected to take approximately one month to complete.
Planned construction (1731-1741 Powell):
- Perform ground improvements
- Excavate retrieval shaft
- Construction hours are Monday to Saturday, 6 a.m. to 8 p.m.
- This Saturday, Jan. 25, construction will be in progress from 7 a.m. to 5 p.m.
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):
- Install ground improvement components within ground improvement shaft
- Work hours are Monday-Friday, 7 a.m. to 5 p.m.
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):
- Install new manhole at Columbus and Union
- Construction hours on Columbus are Monday to Friday, 9 a.m. to 3 p.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.