Construction Updates

A worker prepares a concrete cylinder for installation underground. The cylinder is one component of a wall that will eventually be integrated into the Union Square/Market Street Station.

During the next 10 days, construction to prepare for tunneling will continue in SoMa and Union Square. No Central Subway construction is planned in Chinatown or North Beach; however, demolition of the Pagoda Palace in North Beach is slated to begin in mid-June.

For descriptions of construction impacts in each neighborhood, click here or on the links below. We also post construction information on our project Google Map.

Construction impacts are planned to change at these locations by May 27:

• Northern SoMa (Market to Harrison): On 4th Street between Howard and Folsom, two lanes of traffic will remain open, but the traffic configuration will change starting Thursday, May 23 (details at the Northern SoMa link). On 4th Street between Market and Stevenson, the sidewalk and two traffic lanes will remain closed on the eastern side of the street.
• North Beach: No construction planned before May 27, but demolition of the Pagoda Palace is scheduled to begin in mid-June. For more information, check out this construction notice.

At these locations, current construction impacts are planned to continue until May 27:

• Southern SoMa (Harrison to King/Berry): Full closure of 4th Street between Harrison and Bryant will continue on some evenings and weekends. Two lanes of traffic will remain open at all other times. Please contact us at central.subway@sfmta.com if you have questions about the closure schedule. On Bryant Street at 5th Street, the left lane and several parking spaces will remain closed.
• Union Square: Stockton Street between Geary and Ellis will remain closed to vehicle traffic. Ellis Street between Stockton and Powell will remain closed to westbound traffic.
• Chinatown: No construction planned

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

Crews continue to install subsurface pipes on 4th Street between Market and Stevenson. When the tunnel boring machines pass below, we will use to inject grout into the ground and improve soil conditions here.

During the next 10 days, construction to prepare for tunneling will continue in SoMa and Union Square. No Central Subway construction is planned in Chinatown or North Beach.

For descriptions of construction impacts in each neighborhood, click here or on the links below. We also post construction, traffic detour and Muni impact information on our project Google Map.

Construction impacts are planned to change at these locations by May 20:

• Southern SoMa (Harrison to King/Berry): The on-ramp to westbound I-80 will remain open next week. Full closure of 4th Street between Harrison and Bryant will continue on some evenings and weekends. Two lanes of traffic will remain open on this block on at all other times. Please contact us at central.subway@sfmta.com if you have questions about the closure schedule. On Bryant Street at 5th Street, the left lane and several parking spaces will remain closed.

At these locations, current construction impacts are planned to continue until May 20:

• Northern SoMa (Market to Harrison): On 4th Street between Market and Stevenson, the sidewalk and two traffic lanes will remain closed on the eastern side of the street. Two lanes of traffic will remain closed on 4th Street between Howard and Folsom.
• Union Square: Stockton Street between Geary and Ellis will remain closed to vehicle traffic. Ellis Street between Stockton and Powell will remain closed to westbound traffic.
• Chinatown: No construction planned
• North Beach: No construction planned

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

Crews are excavating a shaft on Ellis Street near where the Central Subway tunnels will pass beneath the existing BART and Muni tunnels. Crews will perform ground improvements here.

During the next 10 days, construction to prepare for tunneling will continue in SoMa and Union Square. No Central Subway construction is planned to occur in Chinatown or North Beach.

Descriptions of construction impacts in each neighborhood are available here or at the links below. We also post construction, traffic detour and Muni impact information on our project Google Map.

Construction impacts are planned to change at these locations by May 13:

• Construction impacts continuing at all sites.

At these locations, current construction impacts are planned to continue until May 13:

• Southern SoMa (Harrison to King/Berry): Full closure of 4th Street between Harrison and Bryant will be in effect some evenings and weekends while we lower parts of the tunnel boring machine into the excavation beneath the roadway. Two lanes of traffic will remain open on this block on at all other times. Please contact us at central.subway@sfmta.com if you have questions about the closure schedule. On Bryant Street at 5th Street, the left lane and several parking spaces will be closed for use as a staging area for tunnel boring machine installation.
• Northern SoMa (Market to Harrison): On 4th Street between Market and Stevenson, the sidewalk and two traffic lanes will remain closed on the eastern side of the street. Two lanes of traffic will remain closed on 4th Street between Howard and Folsom.
• Union Square: Stockton Street between Geary and Ellis will remain closed to vehicle traffic. Ellis Street between Stockton and Powell will remain closed to westbound traffic.
• Chinatown: No construction planned
• North Beach: No construction planned

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

On Ellis Street, crews continue to excavate and stabilize a shaft that will be used to perform ground improvements.

During the next 10 days, construction to prepare for tunneling will continue in SoMa and Union Square, and we will perform a soil boring in North Beach. No Central Subway construction is planned to occur in Chinatown.

Descriptions of construction impacts in each neighborhood are available here or at the links below. We also post construction, traffic detour and Muni impact information on our project Google Map.

Construction impacts are planned to change at these locations by April 29:

• Southern SoMa (Harrison to King/Berry): Starting Monday, April 20, full closure of 4th Street between Harrison and Bryant will be in effect some evenings and weekends while we install a gantry crane and lower a tunnel boring machine into the tunnel launch box. Two lanes of traffic will remain open on this block at all other times. Please contact us at central.subway@sfmta.com if you have questions about the closure schedule.
• Northern SoMa (Market to Harrison): On 4th Street between Folsom and Harrison, all lanes are planned to reopen to traffic on Friday, April 26. On 4th Street between Market and Stevenson, the sidewalk and two traffic lanes will remain closed on the eastern side of the street. Two lanes of traffic will remain closed on 4th Street between Howard and Folsom.
• North Beach: To facilitate a soil boring, the parking lane on Powell Street between Union and Columbus may be closed during construction hours (7 a.m. to 7 p.m.) from Monday, April 22, until Wednesday, April 24.

At these locations, current construction impacts are planned to continue until April 29:

• Union Square: Stockton Street between Geary and Ellis will remain closed to vehicle traffic. Ellis Street between Stockton and Powell will remain closed to westbound traffic.
• Chinatown: No construction planned

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

Construction of underground walls is in progress on 4th Street between Howard and Folsom.

During the next 10 days, construction to prepare for tunneling will continue in SoMa and Union Square. No Central Subway construction is planned to occur in Chinatown or North Beach.

Descriptions of construction impacts in each neighborhood are available here or at the links below. We also post construction, traffic detour and Muni impact information on our project Google Map.

Construction impacts are planned to change at these locations by April 22:

• Southern SoMa (Harrison to King/Berry): Full closure of 4th Street between Harrison and Bryant will be in effect the weekend of April 13-14. Starting Wednesday, April 17, a gantry crane will be installed over 4th Street at the southern end of the block. 4th Street will be closed at night to install the crane. At all other times, two lanes of traffic will remain open on this block.
• Union Square: Starting Saturday, April 13, Saturday work hours at this site will be from 6 a.m. to 10 p.m. Stockton Street between Geary and Ellis will remain closed to vehicle traffic. Ellis Street between Stockton and Powell will remain closed to westbound traffic.

At these locations, current construction impacts are planned to continue until April 22:

• Northern SoMa (Market to Harrison): On 4th Street between Market and Stevenson, the sidewalk and two traffic lanes will remain closed on the eastern side of the street. Two lanes of traffic will remain closed on 4th Street between Howard and Folsom. One lane will remain closed on 4th Street between Folsom and Harrison.
• Chinatown: No construction planned
• North Beach: No construction planned

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

Beneath 4th Street, crews are pouring concrete to build the floor of the tunnel launch box between Harrison and Bryant.

During the next 10 days, construction to prepare for tunneling will continue in SoMa and Union Square. No Central Subway construction is planned to occur in Chinatown or North Beach.

Descriptions of construction impacts in each neighborhood are available here or at the links below. We also post construction, traffic detour and Muni impact information on our project Google Map.

Construction impacts are planned to change at these locations by April 15:

• Southern SoMa (Harrison to King/Berry): Full closure of 4th Street between Harrison and Bryant will be in effect the weekend of April 13-14 to accommodate sewer work. On weekdays and on the weekend of April 6-7, two lanes of traffic will remain open on this block. Launch box construction will continue. Starting Monday, April 15, a gantry crane will be installed over 4th Street at the southern end of the block. 4th Street may be closed at night to install the crane.
• Northern SoMa (Market to Harrison): The temporary taxi stand on 4th Street between Market and Stevenson has been removed due to safety and traffic flow concerns. On that block, the sidewalk and two traffic lanes will remain closed on the eastern side of the street. Two lanes of traffic will remain closed on 4th Street between Howard and Folsom. One lane will remain closed on 4th Street between Folsom and Harrison.
• Union Square: Starting next Saturday, April 13, Saturday work hours at this site will be from 6 a.m. to 10 p.m. Stockton Street between Geary and Ellis will remain closed to vehicle traffic. Ellis Street between Stockton and Powell will remain closed to westbound traffic.

At these locations, current construction impacts are planned to continue until April 15:

• Chinatown: No construction planned
• North Beach: No construction planned

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

On Ellis Street, crews are excavating this shaft to perform ground improvements.

During the next 10 days, construction to prepare for tunneling will continue in SoMa and Union Square. No Central Subway construction is planned to occur in Chinatown or North Beach.

Descriptions of construction impacts in each neighborhood are available here or at the links below. We also post construction, traffic detour and Muni impact information on our project Google Map.

Construction impacts are planned to change at these locations by April 8:

• Construction impacts continuing at all sites.

At these locations, current construction impacts are planned to continue until April 8:

• Southern SoMa (Harrison to King/Berry): On 4th Street between Harrison and Bryant, launch box construction will continue. Two lanes of traffic will remain open. The on-ramp to westbound I-80 may be closed from 8 p.m. to 4 a.m. on weeknights and all day Saturday and Sunday.
• Northern SoMa (Market to Harrison): The sidewalk and three traffic lanes will be closed on the eastern side of 4th Street between Market and Stevenson streets, with a temporary pedestrian walkway around the construction zone and a temporary taxi stand next to the pedestrian walkway. Two lanes of traffic will remain closed on 4th Street between Howard and Folsom. One lane will remain closed on 4th Street between Folsom and Harrison.
• Union Square: Stockton Street between Geary and Ellis will remain closed to vehicle traffic. Ellis Street between Stockton and Powell will remain closed to westbound traffic.
• Chinatown: No construction planned
• North Beach: No construction planned

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

At the site where tunneling will begin, crews have started to build a floor known as a mud slab on the bottom of the excavation.

During the next 10 days, construction to prepare for tunneling will continue in SoMa and Union Square. No Central Subway construction is planned to occur in Chinatown or North Beach.

Descriptions of construction impacts in each neighborhood are available here or at the links below. We also post construction, traffic detour and Muni impact information on our project Google Map.

Construction impacts are planned to change at these locations by April 1:

• Southern SoMa (Harrison to King/Berry): Full closure of 4th Street between Harrison and Bryant may be in effect the weekend of March 30-31 to accommodate sewer work (tentative). On weekdays and on the weekend of March 23-24, two lanes of traffic will remain open on this block. Launch box construction will continue.
• Union Square: Starting Monday, March 25, weekday construction hours will be 6 a.m. to 12:30 a.m. Stockton Street between Geary and Ellis will remain closed to vehicle traffic. Ellis Street between Stockton and Powell will remain closed to westbound traffic.

At these locations, current construction impacts are planned to continue until April 1:

• Northern SoMa (Market to Harrison): The sidewalk and three traffic lanes will be closed on 4th Street between Market and Stevenson streets, with a temporary pedestrian walkway around the construction zone and a temporary taxi stand next to the pedestrian walkway. Two lanes of traffic will remain closed on 4th Street between Howard and Folsom. One lane will remain closed on 4th Street between Folsom and Harrison.
• Chinatown: No construction planned
• North Beach: No construction planned

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

At Union Square, the contractor is continuing to construct below-ground walls in preparation for tunneling.

During the next 10 days, construction to prepare for tunneling will continue in SoMa and Union Square. No Central Subway construction is planned to occur in Chinatown or North Beach.

Descriptions of construction impacts in each neighborhood are available here or at the links below. We also post construction, traffic detour and Muni impact information on our project Google Map.

Construction impacts are planned to change at these locations by March 25:

• Southern SoMa (Harrison to King/Berry): Full closure of 4th Street between Harrison and Bryant may be in effect the weekend of March 23-24 to accommodate sewer work (tentative). On weekdays and on the weekend of March 16-17, two lanes of traffic will remain open on this block. Launch box construction will continue.
• Northern SoMa (Market to Harrison): By Monday, March 25, the sidewalk and three traffic lanes will be closed on 4th Street between Market and Stevenson streets. A temporary pedestrian walkway will be in place around the construction zone when the sidewalk is closed. A temporary taxi stand will be established next to the pedestrian walkway, in the nearest traffic lane. Two lanes of traffic will remain closed on 4th Street between Howard and Folsom. One lane will remain closed on 4th Street between Folsom and Harrison.

At these locations, current construction impacts are planned to continue until March 25:

• Union Square: Stockton Street between Geary and Ellis will remain closed to vehicle traffic. Ellis Street between Stockton and Powell will remain closed to westbound traffic.
• Chinatown: No construction planned
• North Beach: No construction planned

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

A covered walkway has been installed on Stockton Street next to the site where crews are installing underground walls.

During the next 10 days, construction to prepare for tunneling will continue in SoMa and Union Square. No Central Subway construction is planned to occur in Chinatown or North Beach.

Descriptions of construction impacts in each neighborhood are available here or at the links below. We also post construction, traffic detour and Muni impact information on our project Google Map.

Construction impacts are planned to change at these locations by March 18:

• Southern SoMa (Harrison to King/Berry): Full closure of 4th Street between Harrison and Bryant will be in effect from Friday, March 8, at 8 p.m. until Sunday, March 10. At all other times, two lanes of traffic will remain open on this block. Launch box construction will continue.
• Union Square: Starting next week, the contractor will begin working extended hours (until 10 p.m.) on weekdays and during the day on Saturdays. Stockton Street between Geary and Ellis will remain closed to vehicle traffic. Ellis Street between Stockton and Powell will remain closed to westbound traffic.

At these locations, current construction impacts are planned to continue until March 18:

• Northern SoMa (Market to Harrison): One lane will remain closed to traffic on 4th Street between Market and Stevenson. Two lanes of traffic will remain closed on 4th Street between Howard and Folsom. One lane will remain closed on 4th Street between Folsom and Harrison.
• Chinatown: No construction planned
• North Beach: No construction planned

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

Later this year construction of the Central Subway tunnels will begin on 4th Street beneath the I-80 overpass, within a major excavation known as a launch box. Excavation and construction of the launch box began last spring and is expected to continue through spring 2013. When it is complete, the launch box will reach a depth of about 50 feet and span almost the entire block between Harrison and Bryant streets. Tunnel boring machines will then excavate and construct the Central Subway tunnels, one for northbound trains and another for southbound trains.

The underground walls around the perimeter launch box have been completed. Now crews are excavating the launch box, and they recently completed construction of an access ramp.

Check out this video for a view beneath the roadway and to see the ongoing construction at the launch box site.

Today we are excited to announce the debut of our Central Subway construction update emails. These emails will provide information about Central Subway construction along the project alignment in SoMa, Union Square, Chinatown and North Beach.

Starting today, we will email these updates weekly on Fridays to provide an overview of the Central Subway construction that is planned to occur in the next 10 days. To subscribe to the emails, please fill out this online form. If you prefer to view the weekly updates online, we will post links to them here, on Facebook and on Twitter.

The emails will include information about ongoing and upcoming construction; traffic, transit and pedestrian impacts; community meetings and more.

Below is a preview of this week’s debut construction update email. You can view the full version online here.

This rebar cage was installed to form a subsurface wall on 4th Street between Howard and Folsom streets.

Dec. 29, 2012- Jan. 7, 2013

During the next 10 days, construction to prepare for tunneling will continue in SoMa and recommence in Union Square. No Central Subway construction is planned to occur in North Beach or Chinatown.

On New Year’s Day, no Central Subway construction is planned.

For descriptions of construction impacts in each neighborhood, click on the links below. We also post construction, traffic detour and Muni impact information on our project Google Map.

Construction impacts are planned to change at these locations by January 7:

• Southern SoMa (Harrison to King/Berry): No evening or weekend closure of I-80 on-ramp from Dec. 29 to Jan. 1
• Union Square: Construction to resume, with partial closures of Stockton and Ellis streets recommencing Jan. 2

At these locations, current construction impacts are planned to continue until January 7:

• Northern SoMa (Market to Harrison): Continued construction on 4th Street between Howard and Folsom
• Chinatown: No construction planned
• North Beach: No construction planned

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

The tunneling contractor has begun installing below-ground walls to prepare for tunneling at this site on 4th Street between Howard and Folsom streets.

Since our last update, construction in Union Square and North Beach has paused for the holiday season, while work at two sites in SoMa has continued to move forward. In addition, work to install subsurface monitoring equipment has commenced in Chinatown.

Here’s what you can expect in the next three weeks as construction continues in SoMa and Chinatown:

• Tunnel Launch Box (4th Street between Harrison and Bryant streets): The contractor will install beams across the below-ground walls that have been constructed around the perimeter of this site. Excavation and construction of an access ramp is also planned to begin. To facilitate construction, this block of 4th Street will remain closed to all vehicle traffic. The on-ramp to westbound I-80 at 4th and Harrison streets may be closed on weeknights from 8 p.m. to 4 a.m. and all day Saturday and Sunday. The sidewalk on the east side of the block will remain open to pedestrians. Traffic and pedestrian controls are in place. For more information on current construction impacts at this site, please check out this construction notice.

• Yerba Buena/Moscone Station Tunnel Pre-Construction (4th Street between Howard and Folsom streets): The tunneling contractor has commenced installation of below-ground walls, called headwalls, at the site of the future Yerba Buena/Moscone Station. The walls will cross 4th Street at two points on this block. At least two lanes of traffic on 4th Street will remain open at most times; however, the block may be reduced to one lane for one night to facilitate work involving large cranes. The contractor will continue working on the western side of the block, with at least two lanes open on the east side of the street (left lanes for southbound traffic). Pedestrian controls will be in place during periods of sidewalk impact.

• Chinatown Subsurface Instrument Installation (Stockton Street between Sacramento Street and Broadway): Crews will continue installing subsurface instruments that will measure ground conditions related to the Central Subway tunnel. One lane of traffic on up to two approximately half-block sections of Stockton Street may be closed at a time during construction hours. Construction hours are Monday to Friday, 10 p.m. to 7 a.m. More information is available in this construction notice.

We also post construction, auto detour and Muni impact information on our project Google Map.

We appreciate your continued patience while construction is in progress.

This construction site near Union Square will be restored and reopened to traffic during the holiday season.

During the holiday season, construction at some currently active Central Subway construction sites will pause, with roadways and pedestrian walkways restored to regular use. At other sites, construction will continue.

This blog post provides a summary of construction impacts between Thanksgiving and New Year’s Day. For a complete listing of construction impacts, including work hours and traffic and pedestrian impacts, check out this press release from the SFMTA.

No construction will occur at any sites on Thanksgiving, Black Friday, Christmas Day or New Year’s Day.

Construction will continue at this site in SoMa, with the full closure of this block of 4th Street planned to remain in effect between Thanksgiving and New Year’s Day.

Here’s what you can expect in SoMa, Union Square, Chinatown and North Beach during the holiday season:

• Union Square (Stockton Street between Ellis and Geary, Ellis Street between Stockton and Powell): Construction will pause at the site of the future Union Square/Market Street Station. Stockton Street and Ellis Street will be paved and reopened to traffic by Thanksgiving Day. After New Year’s Day, this section of Stockton Street will again close to traffic, and construction on Ellis Street will also begin again.

• SoMa (4th Street between Harrison and Bryant): The contractor will work through the holiday season to construct a major excavation known as a launch box. 4th Street will remain closed to vehicle traffic. The sidewalk on the east side of the street will remain open to pedestrians. The on-ramp to westbound I-80 at 4th and Harrison may be closed on evenings and weekends.

• SoMa (4th Street between Folsom and Harrison): Starting in December, the contractor will be excavating shallow trenches on the east side of the road and installing pipes to be used for ground improvement related to tunneling. The easternmost lane (left lane for southbound traffic) may be closed during limited times during construction hours (Monday to Friday, 6 a.m. to 10 p.m.).

• SoMa (4th Street between Folsom and Howard): Construction of below-ground walls, called headwalls, at the site of the future Yerba Buena/Moscone Station will continue through the holiday season. At least three lanes on 4th Street will be open to traffic during regular construction hours (Monday to Saturday, 7 a.m. to 10 p.m.). Night work may occur, and traffic may be reduced to two lanes between 10 p.m. and 7 a.m. The sidewalk on the western side of the street may be impacted. Pedestrian detours will be provided.

• Chinatown (Stockton Street between Sacramento and Vallejo): Construction will commence in December to install subsurface monitoring instruments related to the Central Subway tunnel. One lane on Stockton Street may be closed during construction hours in the vicinity of construction zones. Lane closures will impact traffic on up to two approximately half-block sections of Stockton Street at a time during construction hours (Monday to Friday, 10 p.m. to 7 a.m.)

• North Beach (Columbus Avenue between Union and Filbert): This construction site will be paved and reopened to traffic by Thanksgiving. Central Subway crews will not be working in this area during the holiday season; however, AT&T may be performing work related to the Central Subway. AT&T’s work will involve a crew of approximately two people working inside manholes. No street excavation will occur as part of AT&T’s work.

We wish you a happy holidays, and we thank you for your continued patience as construction progresses.

Construction at the site where tunneling will begin next year.

Along the Central Subway Project alignment, tunnel pre-construction has continued to progress at the four active construction sites. Since our last update, crews have completed construction of a sewer manhole and a sewer line in North Beach, and a portion of 4th Street has closed to facilitate construction of a major excavation known as a launch box at the site where tunneling will begin next year.

This construction update covers construction that will be underway from Saturday, November 10, until Wednesday, November 21. We will post an additional update soon with information about construction during the holiday season.

In the next week and a half, work will continue at the four active Central Subway construction sites, with traffic impacts planned to change at the following location:

• North Beach Utility Relocation (Columbus Avenue between Union and Filbert streets): The contractor plans to begin work on the western (southbound) side of Columbus Avenue on Tuesday, November 13. The right lane for southbound traffic will be closed during construction hours (Monday to Friday, 7 a.m. to 3:30 p.m.). To facilitate construction, the southbound bus stop on Columbus Avenue at Union Street will be closed during construction hours. The nearest alternate bus stop for the 30 Stockton is on Columbus Avenue at Filbert Street. The nearest alternate stop for the 8X/8BX Bayshore Express is on Powell Street at Filbert Street. ***Update November 13: In North Beach, the contractor will no longer begin work on the western side of Columbus Avenue today. Work will continue on the eastern side of the street and in the median. The left lane for northbound traffic and the northbound bus stop on Columbus Avenue at Union Street will remain closed during construction hours. Both southbound lanes of traffic and the southbound bus stop on Columbus Avenue at Union Street will remain open.***

Construction at the site in SoMa where tunneling will begin next year.

Here’s what to expect in the next week and a half as tunnel pre-construction continues in SoMa, Union Square and North Beach:

• Tunnel Launch Box (4th Street between Bryant and Harrison streets): The contractor will continue constructing below-ground walls around the perimeter of this major excavation site. In addition, at the southern end of the block, crews are building a structure that will support the decking that will eventually cover the launch box, allowing traffic to travel over the excavation. To facilitate construction, this block of 4th Street is closed to all vehicle traffic. The on-ramp to westbound I-80 may be closed on weeknights from 8 p.m. to 4 a.m. and all day Saturday and Sunday. The sidewalk on the east side of the block remains open to pedestrians, and traffic and pedestrian controls are in place. For more information on construction impacts near this site, please check out this construction notice.

• Yerba Buena/Moscone Station Tunnel Pre-Construction (4th Street between Folsom and Howard streets):  The tunneling contractor will continue preparing to install below-ground walls, called headwalls, at the site of the future Yerba Buena/Moscone Station. The walls will cross 4th Street at two points on this block. At least two lanes of traffic on 4th Street will remain open at all times. The contractor plans to remain on the eastern side of the street until November 21, with two lanes on the west side of the street (right lanes for southbound traffic) open.

• Union Square Tunnel Pre-Construction (Stockton Street between Ellis and Geary streets and Ellis Street between Stockton and Powell streets): The contractor will continue preparing to construct below-ground walls at the future site of the Union Square/Market Street Station. Stockton Street between Ellis and Geary streets will remain closed to all traffic except emergency vehicles. Ellis Street between Powell and Stockton streets will remain closed to westbound traffic. Sidewalks in the area will remain open to pedestrians. For more information about the traffic modifications now in effect in the Union Square area, check out this blog post.

• North Beach Utility Relocation (Columbus Avenue between Union and Powell streets): The contractor will continue with utility relocation. On Monday, November 12, the left lane for northbound traffic will be closed during construction hours. Starting Tuesday, November 13, the work area will shift to the southbound side of the street. The right lane for southbound traffic will be closed during construction hours (Monday to Friday, 7 a.m. to 3:30 p.m.).  To facilitate construction, the southbound bus stop on Columbus Avenue at Union Street will be closed during construction hours. Signage will be in place directing Muni customers to the closest alternate bus stops. For more information on construction in North Beach, check out this blog post. ***Update November 13: In North Beach, the contractor will no longer begin work on the western side of Columbus Avenue today. Work will continue on the eastern side of the street and in the median. The left lane for northbound traffic and the northbound bus stop on Columbus Avenue at Union Street will remain closed during construction hours. Both southbound lanes of traffic and the southbound bus stop on Columbus Avenue at Union Street will remain open.***

We also post construction, auto detour and Muni impact information on our project Google Map.

We appreciate your continued patience while construction is in progress.

This construction site on Stockton Street recently hosted an event to celebrate approval of major federal funding for the Central Subway.

Tunnel pre-construction remains underway at four construction sites along the Central Subway Project alignment, including the site shown above, which last week hosted a ceremony to celebrate approval of federal funding to extend the T Third Line through SoMa, Union Square and Chinatown.

In the next three weeks, work will continue at the four Central Subway construction sites, with traffic impacts planned to change at the following two:

• Tunnel Launch Box (4th Street between Bryant and Harrison streets): Beginning Monday, October 29, this block of 4th Street will be closed to traffic to facilitate construction of the Central Subway tunnel. The closure is anticipated to be in effect for approximately three months. In addition, the on-ramp to I-80 West may be closed on weeknights and weekends. During Giants games, two lanes of traffic on 4th Street will be open. For additional information, check out this construction notice.

• North Beach Utility Relocation (Columbus Avenue between Union and Filbert streets): The contractor expects to begin work on the eastern side of Columbus Avenue during the next three weeks. We will provide additional details about traffic, transit and pedestrian impacts in advance of this change.

Next year tunneling will begin at this site in SoMa. To prepare for tunneling, this block of 4th Street will be closed to traffic for about three months, beginning October 29.

Here’s what to expect in the next three weeks as tunnel pre-construction continues in SoMa, Union Square and North Beach:

• Tunnel Launch Box (4th Street between Bryant and Harrison streets): The contractor will continue performing ground-stabilization work and constructing below-ground walls around the perimeter of this major excavation site. To facilitate construction, this block of 4th Street will be closed to traffic beginning Monday, October 29, and continuing for approximately three months. In addition, the on-ramp to westbound I-80 may be closed on weeknights from 8 p.m. to 4 a.m. and all day Saturday and Sunday. For more information on this closure, please check out this construction notice. The sidewalk on the east side of the block will remain open to pedestrians, and traffic and pedestrian controls will be in effect.

• Yerba Buena/Moscone Station Tunnel Pre-Construction (4th Street between Folsom and Howard streets):  The tunneling contractor will continue preparing to install below-ground walls, called headwalls, at the site of the future Yerba Buena/Moscone Station. The walls will cross 4th Street at two points on this block. At least two lanes of traffic on 4th Street will remain open at all times. During the next three weeks, the contractor expects to remain on the eastern side of the street, with two lanes on the west side of the street (right lanes for southbound traffic) open.

• Union Square Tunnel Pre-Construction (Stockton Street between Ellis and Geary streets and Ellis Street between Stockton and Powell streets): The contractor will continue preparing to construct below-ground walls at the future site of the Union Square/Market Street Station. Stockton Street between Ellis and Geary streets will remain closed to all traffic except emergency vehicles. Ellis Street between Powell and Stockton streets will remain closed to westbound traffic. Sidewalks in the area will remain open to pedestrians. For more information about the traffic modifications now in effect in the Union Square area, check out this blog post.

• North Beach Utility Relocation (Columbus Avenue between Union and Powell streets): The contractor will continue with utility relocation, constructing a sewer line and two sewer manholes. Currently the left lane for northbound traffic is closed, and work is underway in the intersection of Columbus Avenue and Union Street. To facilitate construction, the southbound bus stop on Columbus Avenue at Union Street will be closed during construction hours. In the next three weeks, the contractor plans to move to the eastern side of Columbus Avenue between Union and Filbert streets, and new traffic and transit impacts will be in effect. We will provide additional details in advance of these changes. For more information on construction in North Beach, check out this blog post.

A complete, current three-week construction schedule, including detailed, site-specific transit and traffic impacts, is available online for the tunnel contract. We also post construction, auto detour and Muni impact information on our project Google Map.

We appreciate your continued patience while construction is in progress.

The traffic configuration near this construction site in SoMa will be modified starting Saturday.

Starting Saturday, September 29, a new traffic pattern will be established on 4th Street between Harrison and Bryant streets, at the site where tunneling will begin next year. To facilitate construction in the northwest and southeast sections of the block, vehicles traveling through the area will be directed as follows:

• On the northern part of the block, between Harrison and Perry streets, two lanes on the eastern side of the street (left lanes for southbound traffic) will be open.
• Near the intersection of 4th and Perry streets, traffic will be shifted toward the western side of the street.
• On the southern part of the block, between Perry and Bryant streets, two lanes on the western side of the street (right lanes for southbound traffic) will be open.

In addition, work will be underway in the intersection of 4th and Harrison streets near the entrance to westbound I-80, and one lane of traffic on Harrison Street between 4th and Lapu Lapu streets may be closed.

This lane of traffic on Harrison Street may remain closed while construction is in progress.

Traffic controls and directional signage will be in place, and the speed limit through this area will be reduced to 20 MPH.

This traffic configuration is expected to be in effect for approximately six weeks. Motorists are advised to exercise caution while traveling through the area.

This block of Columbus Avenue in North Beach is temporarily restored for traffic at the end of each work day.

With autumn just around the corner, tunnel pre-construction continues to move forward in SoMa, Union Square and North Beach. As tunneling contractor Barnard Impregilo Healy JV completes work along the alignment, new traffic configurations are being established at three construction sites.

• At the construction site on 4th Street between Bryant and Harrison streets where tunneling will begin next year, the contractor expects to finish installing below-ground walls for the tunnel boring machine launch box on the west side of the block by the end of September. The construction zone will then move to the east side of the block, and a new traffic configuration will be established. We will provide additional details in advance of this change.

• Farther north on 4th Street, the contractor completed installation of guide walls on the western portion of the block between Folsom and Howard streets. This week the contractor moved to the east side of the block and has begun demolishing utilities to prepare for guide wall installation. Two lanes remain open on the west side of the block. Guide walls are shallow, subsurface walls that help guide the equipment that will be used to construct the much deeper headwalls.

• In North Beach, the contractor plans to begin installing a sewer manhole on Columbus Avenue between Union and Powell streets next Thursday, September 13. To accommodate construction, the left lane for northbound traffic will be closed on this block during construction hours. Currently the right lane for northbound traffic is closed during construction hours on this block.

The contractor completed construction of these guide walls on the west side of 4th Street between Folsom and Howard streets. Work is now underway on the east side of this block.

Here’s what to expect in the next three weeks as tunnel pre-construction continues in SoMa, Union Square and North Beach:

• Tunnel Launch Box (4th Street between Bryant and Harrison streets): The contractor will continue constructing below-ground walls around the perimeter of this major excavation site. Current work hours here are 5 a.m. to 1 a.m., Monday through Friday, and 6 a.m. to 4 p.m. on Saturday. At least two lanes of traffic on 4th Street will remain open at all times.

• Yerba Buena/Moscone Station Headwalls (4th Street between Folsom and Howard streets):  The tunneling contractor will install below-ground walls, called headwalls, at the site of the future Yerba Buena/Moscone Station. The walls will cross 4th Street at two points on this block. Current work hours at this site are 7 a.m. to 4 p.m., Monday through Friday. At least two lanes of traffic on 4th Street will remain open at all times.

• Union Square Tunneling Pre-Construction (Stockton Street between Ellis and Geary streets and Ellis Street between Stockton and Powell streets): The contractor is performing utility demolition and ground stabilization work, called jet grouting. Installation of below-ground walls, called headwalls, will follow. Current construction hours at this site are Monday to Friday, 6 a.m. to 5 p.m. For more information about the traffic modifications now in effect in the Union Square area, check out this recent blog post.

• North Beach Utility Relocation (Columbus Avenue between Union and Powell streets): The contractor will continue with utility relocation. Construction hours are Monday through Friday, 7 a.m. to 3:30 p.m. One lane of traffic will be closed at a time on one block of Union Street, Powell Street or Columbus Avenue during construction hours. For more information on construction in North Beach, check out this recent blog post.

A complete, current three-week construction schedule, including detailed, site-specific transit and traffic impacts, is available online for the tunnel contract. We also post construction, auto detour and Muni impact information on our project Google Map.

We appreciate your continued patience while construction is in progress.

To avoid traffic congestion on this section of 4th Street, we suggest using the detours described below.

As tunneling contractor Barnard Impregilo Healy Joint Venture continues to make progress on tunnel pre-construction work, traffic configurations at a construction site in SoMa will be modified next week, starting Tuesday, September 4.

No Central Subway construction will occur on Monday, September 3, in observance of Labor Day.

At the future site of the Yerba Buena/Moscone Station, the contractor will start work on the east side of 4th Street.

• Traffic impacts: Two lanes will remain open to traffic on the west side of 4th Street. (Currently the two open lanes are on the east side of the street.)  Temporary lane striping will be in place at and around the intersection of 4th and Howard streets to direct traffic to the appropriate lanes.

• Parking impacts: Parking will be impacted on 4th Street between Folsom and Howard streets and on Clementina Street near the intersection with 4th Street.

• Suggested detours for freeway access: Traffic delays are anticipated. Motorists are encouraged to use the onramp at Harrison and 7th streets as an alternative to access westbound I-80 while launch box construction is in progress. Those traveling to the peninsula may prefer to access the I-280 via 6th Street or Highway 101 via 10th Street.

• Pedestrian impacts: The sidewalks on the west side of 4th Street will be restored for pedestrian use.

More information about the work currently underway at this site is available here.

This entrance to the Powell Street Station, located next to the Apple Store at Stockton and Ellis streets, will close next Monday.

Starting next Monday, August 27, the entrance to the Powell Street Station located at Stockton and Ellis streets will close to accommodate Central Subway construction. The closure of this entrance, also known as the Apple Store entrance, will be in effect for approximately six years to facilitate construction of the Central Subway tunnel and Union Square/Market Street Station.

When the Central Subway opens in 2019, this entrance will provide convenient access to the T Third Line at the future Union Square/Market Street Station. An underground concourse connection will link the Union Square/Market Street and Powell Street stations, allowing customers to transfer easily between the T Third Line and the BART and Muni Metro lines operating in the Market Street tunnel.

To facilitate access to Powell Street Station while the Apple Store entrance is closed, signage will direct customers to the nearest alternate entrance at 4th and Market streets.

More information is available in this press release from the SFMTA.

We appreciate your continued patience while construction is in progress.