Pictured below is the bottom half of the sewer line before installation of a reinforced concrete roof designed to support the weight of passing light rail vehicles.

Triton safety barriers outline work at the intersection of 4th and King, which is the future extension of the current T Third Line.  This connection will allow trains to travel north and south on 4th Street.

Want to see more photos of project construction?  Check out our Flickr, updated weekly!

Rebar cage installation is complete and concrete will soon be poured for the roof deck of the future Yerba Buena|Moscone Station.

We made some changes to our weekly construction update.

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 work activities, traffic and transportation impacts 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.

Starting Monday, June 8-July 3, the contractor will be 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.

On Tuesday, June 9 from 7p.m. to 5a.m., the San Francisco Water Department will be performing a pipeline tie-in work on Stockton Street between Jackson and Sacramento.

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 this city’s public transportation system.

The Central Subway Team

The new fire hydrant on Washington Street at Stockton Street.

Also in the Chinatown neighborhood, Central Subway ambassadors increase safety by guiding pedestrians at intersections on Stockton and Washington streets adjacent to the construction site.

Pictured clockwise: 1) Map indicating area of construction 2) Ambassador at Washington and Stockton streets 3) Site of the future Chinatown Station

Ambassadors help the public at the intersection of Stockton and Washington streets.

Fridays we post the most up-to-date construction information.

The cutter head of tunnel boring machine (TBM) Mom Chung can be seen in the background as workers disassemble the shield of TBM Big Alma.

During the next 10 days, Central Subway work continues 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 click here or on the links below. You can also find construction, traffic detour, and Muni impact information on our project Google Map. For safety reasons, we encourage the public to follow all traffic and pedestrian notifications posted at the work sites.

Southern SoMa (Harrison to King/Berry): Potholing for utilities continues next week on 4th Street between Bryant and King. On Brannan between 4th and 5th Streets, work on utilities continues. Temporary walkways are in place around the construction zones.

Northern SoMa (Market to Harrison): At 4th and Folsom, work to build the Yerba Buena/Moscone Station continues. This includes construction of the station walls within the work site and water line replacement at the intersection of 4th and Folsom. Until Monday, July 28, 4th Street from Howard to Folsom streets will have one traffic lane. This area will continue to have a lane reduction overnight from 7 p.m. to 5 a.m.

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 for pile installation to construct the station walls. For the month of July, Stockton Street between Post and Geary will be closed to vehicular traffic. Please use alternate routes and follow construction signs.

Pile installation takes place at the southwest intersection of Stockton and O’Farrell streets until August 18. One lane of travel will be open. Expect delays and please use alternative routes.

Muni service impact:
Until August 1, the bus stop at Geary and Stockton will be temporarily discontinued. Please board bus at Geary and Powell. Please check back on our weekly Construction Update for the most current information on the re-opening of this stop.

Chinatown:  The contractor started station wall construction at the future station site and on the adjacent section of Washington Street. Work to replace high pressure water pipeline and install new fire hydrant on Washington is ongoing. A section of the sidewalk at the northeast corner of the Washington and Stockton intersection will be demolished in order to install a new fire hydrant.

North Beach: Work continues at 1731-1741 Powell. Sustainable Streets is constructing bulbs on Columbus Avenue between Filbert and Union streets, and widening the sidewalk on both sides of the street for this block. Street restoration work is expected to be completed by the end of August. More information is available in this notice.

We thank the businesses, residents, shoppers, and commuters of San Francisco for their continued engagement with this significant investment in the extension of our public transportation system.

At the retrieval shaft in North Beach, portions of the body of the tunnel boring machines (TBMs) are awaiting removal from the site.

During the next 10 days, Central Subway work continues 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, click here or on the links below. You can also find construction, traffic detour, and Muni impact information on our project Google Map. For safety reasons, we encourage the public to follow all traffic and pedestrian notifications posted at the work sites.

Southern SoMa (Harrison to King/Berry): Potholing for utilities continues next week on 4th Street between Bryant and King. On Brannan between 4th and 5th Streets, work on utilities continues. Temporary walkways are in place around the construction zones.

Northern SoMa (Market to Harrison): At 4th and Folsom, work to build the Yerba Buena/Moscone Station continues. This includes construction of the station walls within the work site and water line replacement at the intersection of 4th and Folsom. One lane of traffic continues on 4th between Howard and Folsom streets from 7 p.m. to 5 a.m. through next week.

On Tuesday, July 22 from 2 p.m. to 5 p.m. 4th Street from Howard to Folsom streets will have one traffic lane.

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 for pile installation to construct the station walls. For the month of July, Stockton Street between Post and Geary will be closed to vehicular traffic. Please use alternate routes and follow construction signs.

Pile installation takes place at the southwest intersection of Stockton and O’Farrell Streets until August 18. One lane of travel will be open. Expect delays and please use alternative routes.

Muni service impact:
Until August 1, the bus stop at Geary and Stockton will be temporarily discontinued. Please board bus at Geary and Powell. Please check back on our weekly Construction Update for the most current information on the re-opening of this stop.

Chinatown:  The contractor started station wall construction at the future station site and on the adjacent section of Washington Street. Work to replace high pressure water pipeline and install new fire hydrant on Washington is ongoing. Installation of observation wells at the corner of Washington and Stockton Streets may take place July 24 and July 25 from 7 p.m. to 3 a.m.

North Beach: Work continues at 1731-1741 Powell. Sustainable Streets is constructing bulbs on Columbus Avenue between Filbert and Union Streets, and widening the sidewalk on both sides of the street for this block. Street restoration work is expected to be completed by the Fall of 2014. More information is available in this notice.

We thank the businesses, residents, shoppers, and commuters of San Francisco for their continued engagement with this significant investment in the extension of our public transportation system.

Now that tunneling is complete, the TBM “Big Alma” is being prepped for removal.

During the next 10 days, Central Subway work will continue at sites in SoMa, Union Square, Chinatown and North Beach. This post contains brief updates about what is happening in each neighborhood. For more detailed information, click here or 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. Hydrant relocation work to occur at 4th and Bryant. On Brannan between 4th and 5th Streets, sidewalk construction to occur. Temporary walkways are in place around the construction zones.

Northern SoMa (Market to Harrison): At 4th and Folsom, work to build the Yerba Buena/Moscone Station continues. This includes construction of the station walls within the work site and water line replacement at the intersection of 4th and Folsom.

Union Square: To allow for construction of the Union Square/Market Street Station, Stockton Street between Ellis and Geary is closed to vehicular traffic. Work is underway for pile installation to construct the station walls. For the month of July, Stockton Street between Post and Geary will be closed to vehicular traffic. Please use alternate route and follow construction signs.

From July 7 to July 30, the bus stop at Geary and Stockton will be temporarily discontinued. Please board bus at Geary and Powell. Service at this stop may be resumed Thursday, July 31 at 5 a.m.

Starting Friday, July 11 through the weekend, pile installation will take place at the intersection of Stockton and O’Farrell Streets. Expect work 24 hours a day until Monday, July 14 at 5 a.m.

Chinatown:  The contractor has started station wall construction within the future station site and on the adjacent section of Washington Street. Work to replace high pressure water pipeline and install new fire hydrant on Washington is ongoing.

North Beach: At 1455 Stockton, the parking lot behind the Bank of America is now restored. The contractor has vacated this location. Work will continue at 1731-1741 Powell. Sustainable Streets is constructing bulbs on Columbus Avenue between Filbert and Union Streets, and widening the sidewalk on both sides of the street for this block. Street restoration work is expected to be completed by the 3rd Quarter of 2014. More information is available in this notice.

We appreciate your patience and support while we build this essential upgrade to San Francisco’s public transportation system.

-The Central Subway Team

Union Square/Market Street Detours

Starting July 1, Stockton Street between Post and Geary will be closed for one month to vehicular traffic. Please use alternate route and follow construction signs.

During the next 10 days, Central Subway work will continue at sites in SoMa, Union Square, Chinatown and North Beach. This post contains brief updates about what is happening in each neighborhood. For more detailed information, click here or 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. Hydrant relocation work to occur at 4th and Bryant. On Brannan between 4th and 5th Streets, sidewalk construction to occur. Temporary walkways are in place around the construction zones.

Northern SoMa (Market to Harrison): At 4th and Folsom, work to build the Yerba Buena/Moscone Station continues. This includes construction of the station walls within the work site and water line replacement at the intersection of 4th and Folsom.

Union Square: To allow for construction of the Union Square/Market Street Station, Stockton Street between Ellis and Geary is closed to vehicular traffic. Work is underway for pile installation to construct the station walls. Beginning June 30 to July 31, every Monday through Thursday, the bus stop at Geary and Stockton will be temporarily relocated to mid-block between Stockton and Grant from 8 p.m. to 4 a.m. From July 11 to July 25, the bus stop at Geary and Stockton will be temporarily relocated every Friday at 10 p.m. through the weekend. Service will resume every Monday at 5 a.m. Signage will be posted.

Chinatown:  The contractor has started station wall construction within the future station site and on the adjacent section of Washington Street. Work to replace high pressure water pipeline and install new fire hydrant on Washington is ongoing.

North Beach: At 1455 Stockton, the restoration of the parking lot behind the Bank of America will be completed. Work will continue at 1731-1741 Powell. Sustainable Streets is constructing bulbs on Columbus Avenue between Filbert and Union Streets, and widening the sidewalk on both sides of the street for this block. Street restoration work is expected to be completed by the 3rd Quarter of 2014. More information is available in this notice.

We appreciate your patience and support while we build this essential upgrade to San Francisco’s public transportation system.

On Wednesday, June 11, tunnel boring machine Big Alma joined her sister TBM Mom Chung to break through the concrete wall of the North Beach retrieval shaft.

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, click here or 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.

Northern SoMa (Market to Harrison): At 4th and Folsom, work to build the Yerba Buena/Moscone Station continues. This will include construction of the station walls within the work site and water line replacement at the intersection Fourth and Folsom. Night work is planned for these activities.

Union Square: Stockton Street between Ellis and Geary is closed to vehicular traffic and partial closure to vehicular traffic between Geary to Post to allow for construction of the Union Square/Market Street Station. Work is underway for pile installation to construct the station walls. Construction hours will be Monday to Saturday from 7 a.m. to 11 p.m. Beginning May 30 to July 25, the bus stop at Geary and Stockton will be temporarily be closed every Friday at 10 p.m. through the weekend. Service will resume every Monday at 4a.m. Muni service for this location will temporarily stop Mondays through Thursdays from 8 p.m. to 4 a.m.

Chinatown:  The contractor has started 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. Roadway and sidewalk restoration on Columbus and Union will continue and is expected to be completed by the 3^rd quarter of 2014.

We appreciate your patience and support while we build this essential upgrade to San Francisco’s public transportation system.

-The Central Subway Team

Work to prepare for surface track construction on 4th Street involves locating and moving underground utilities.

At 4th and Bryant I-80 off-ramp, three lanes may be closed on weeknights from 12 a.m. to 5 a.m. and one lane may be closed during the daytime from 10 a.m. to 3 p.m.

In Union Square, one traffic lane will be closed from Geary to Powell from 8p.m. to 4a.m. starting Tuesday, May 20.

At 1455 Stockton Street, the contractor will be demobilizing and delivering oversize equipment next Wednesday, May 21 to Friday, May 23 between the hours of 11 p.m. to 6 a.m.

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, click here or 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. Three lanes of the I-80 off-ramp at 4th and Bryant may be closed weeknights from 12 a.m. to 5 a.m. One lane of the I-80 off-ramp at 4th and Bryant may be closed during the daytime from 10 a.m. to 3 p.m.

Northern SoMa (Market to Harrison): At 4th and Folsom, work to prepare for the Yerba Buena/Moscone Station continues. This will include construction of the station walls within the work site and water line replacement at the intersection Fourth and Folsom. Night work is planned for these activities.

Union Square: Stockton Street between Ellis and Geary is closed to vehicular traffic and partial closure to vehicular traffic between Geary to Post 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 Monday to Saturday from 7 a.m. to 11 p.m. Starting Tuesday, May 20, one traffic lane will be closed on Geary between Stockton and Powell from 8 p.m. to 4 a.m.

Chinatown:  The contractor has started 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. Sewer, roadway and sidewalk restoration on Columbus and Union will continue and is expected to be completed by the 3^nd quarter of 2014.

We appreciate your patience and support while we build this essential upgrade to San Francisco’s public transportation system.

At the intersection of Ellis and Stockton, the tunneling contractor has restored this work zone and handed it over to the station contractor.

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, click here or 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. Three lanes of the I-80 off-ramp at 4th and Bryant may be closed Tuesday and Wednesday from 12 a.m. to 5 a.m. One lane of the I-80 off-ramp at 4th and Bryant may be closed Monday from 10 a.m. to 3 p.m.

Northern SoMa (Market to Harrison): At 4th and Folsom, work to prepare for the Yerba Buena/Moscone Station continues. This will include demolishing the roadway within the construction zone to prepare to construct underground station walls at 4th and Folsom at night. At 4^th and Jessie, crews are potholing for utilities and will be installing a manhole in the next few weeks.

Union Square: Stockton Street between Ellis and Geary is closed to vehicular traffic and partial closure to vehicular traffic between Geary to Post 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 Monday to Friday from 7 a.m. to 11 p.m.

Chinatown:  The contractor has started 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. Sewer, roadway and sidewalk restoration on Columbus and Union will continue and is expected to be completed by the 3^nd quarter of 2014.

We appreciate your patience and support while we build this essential upgrade to San Francisco’s public transportation system.