January 4-13, 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 expect to begin potholing for utilities on 4th Street between Bryant and King in mid-January. At the tunnel launch box on 4th Street between Harrison and Bryant, tunneling continues with both TBMs.
Northern SoMa (Market to Harrison): We plan to begin restoring 4th Street between Folsom and Harrison during the next two weeks. Until then, the traffic pattern may change to allow for underground sewer surveys. 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.
Union Square: Next week, Stockton Street between Ellis and Geary will be closed to vehicular traffic to allow for construction of the Union Square/Market Street Station. The construction zone on Ellis Street will remain in place.
Chinatown: Work to prepare for the Chinatown Station continues within the future station site and on the adjacent section of Washington Street. On Jackson Street adjacent to Stockton Street, the contractor may be performing underground borings some nights next week.
North Beach: Work on Columbus Avenue at Union Street may resume next week. Work will continue at 1455 Stockton and 1731-1741 Powell, within the property lines.
We appreciate your patience and support while we build this essential upgrade to San Francisco's public transportation system.
-The Central Subway Team 
Workers have recently finished the conveyor system for tunnel boring machine Big Alma. This system transports ground spoils from the underground TBM launch site at 4th and Harrison.
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.
On 4th Street between Bryant and King streets, we plan to begin potholing for utilities mid-January. 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 King mid-January
Traffic and pedestrian impacts (Bryant to King):
- None planned
The teeth of a clamshell bucket waiting to be used at the Yerba Buena/Moscone Station site can be seen, with the recently-installed pedestrian walkway in the background.
Northern SoMa
4th Street from Market to Harrison
On 4th Street between Market and Stevenson, construction is currently paused, to resume when the second TBM reaches 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 by mid-January.
Planned construction (Market to Stevenson):
- None planned
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):
- Construct covered walkway on 4th Street and Clementina, adjacent to construction site
- Planned work hours are Monday to Friday, 7 a.m. to 5 p.m.
- Perform underground sewer surveys on Folsom near the intersection with 4th. This work may occur at night.
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):
- Restore construction site
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
Stockton street has been temporarily graded and repaved for use during the holiday season.
Union Square
Stockton Street from Market to Post
Beginning Monday, January 6, Stockton Street between Ellis and Geary streets will be closed to all vehicles except emergency vehicles. Central Subway Stations contractor Tutor Perini will be installing custom walkway barrier on Stockton Street from 7 a.m. to 5 p.m.
Ground improvement related to tunneling will be in progress on Ellis Street between Stockton and Powell streets.
Planned construction:
- Install custom walkway barrier.
- Work hours are Monday-Friday, 7 a.m. to 5 p.m. Evening and weekend work may be required.
- Tentative: Prepare to build underground subway station walls. This work, which involves breaking and removing the roadway pavement, may be noisy.
Traffic, transit and pedestrian impacts (Stockton Street):
- Stockton Street between Ellis and Geary is closed to vehicular traffic.
- When construction resumes on Stockton Street, 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 and this press release. 
A temporary closure of Washington Street between Stockton Street and Trenton Alley is in effect, while crews relocate utilities and begin constructing underground 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
- On Jackson Street, the contractor may be performing underground borings some nights next week.
- Perform soil boring on Clay, Stockton and Washington streets
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
At 1731-1741 Powell, we are constructing a retrieval shaft to remove two tunnel boring machines from the ground when tunneling is finished.
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.
Near the intersection of Columbus Avenue and Union Street, construction may resume next week. The contractor is completing utility work. More information is available in this flier.
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.
Planned construction (Pagoda):
- Install pipes underground for ground improvements
- Planned construction hours are Monday to Saturday, 6 a.m. to 8 p.m.
Traffic, transit and pedestrian impacts (Pagoda):
- 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 (Columbus and Union):
- The contractor may resume improving sewer lines the week of Jan. 6
- Construction hours 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.
- Tentative: Parking restrictions may be in effect on the south side of Filbert Street between Powell and Stockton. The contractor may use this as a staging area for sewer slip lining work.
Planned construction (1455 Stockton):
- Install ground improvement components from 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
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.