Construction Update: Tunnel prep work progressing, full closure of 4th Street under I-80 overpass starting soon
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.