101 Alemany Construction Information & FAQs
The project area for the U.S. 101 Deck Replacement at San Francisco’s Alemany Circle is from the U.S. 101 and I-280 connector on northbound and southbound 101.
To complete the project as safely and efficiently as possible, construction is scheduled to take place 24 hours a day. We will make every effort to minimize the disruption and thank you in advance for your understanding.
Construction will take place over the following key phases:
Rebuilding Northbound 101
With the I-280 detour in place and northbound U.S. 101 lanes closed, the northbound deck will be demolished and reconstructed. To minimize noise, dust, and vibrations from the project, Caltrans will be sawing away sections of the bridge deck and removing them whole, rather than jackhammering to demolish the bridge deck.
We want to acknowledge that while there will be less noise by using the sawing method, it will still be noisy in the surrounding neighborhoods. We thank you in advance for your patience as we work to complete this project as safely, swiftly, and quietly as possible.
Shifting Southbound 101 Traffic
After the northbound deck is completed, southbound 101 traffic will be diverted onto the new northbound deck at the I-280 connector.
A truck will put in a temporary median for the traffic detour. Installation of the median may have minimal noise impacts, but there may be traffic delays as drivers adjust to the detour. Signs alerting northbound drivers to the detour will be placed on U.S. 101 ahead of the I-280 connector.
Rebuilding Southbound 101
After southbound 101 traffic is shifted onto the newly completed northbound deck, construction will start to demolish and reconstruct the southbound deck. Again, to reduce noise, dust, and vibrations from the project, Caltrans will be sawing away sections of the bridge deck and removing them whole, rather than jackhammering to demolish the bridge deck. We recognize that while sawing the deck sections will result in less noise, it will still be noisy in the surrounding
neighborhoods. We thank you in advance for your patience as we work to complete this project as safely, swiftly, and quietly as possible.
Restoring U.S. 101 Traffic
With completion of both the northbound and southbound bridge decks, U.S. 101 traffic will be shifted back to its original configuration.
Check back here for additional information and updates about construction.
Frequently Asked Questions
Why does the Alemany Deck need to be replaced?
Investing in Bay Area infrastructure is critical to the safe movement of people and goods through our region. The U.S. 101 Alemany Project is required to maintain the safety of the bridge deck, originally constructed in 1950. Inspection reports for the Alemany bridge deck noted cracking and corrosion and recommended replacement.
The columns and foundation are in good condition, then will construction work be taking place?
The construction team will work 24/7, beginning in late April, and will continue through early May.
How will traffic be impacted?
Because construction is happening during the state-wide stay at home order, while traffic levels are down 40-60 percent, traffic impacts will be significantly reduced for the duration of this project. Northbound 101 traffic will be rerouted onto 280 at the highway interchange. Once construction of the northbound deck
is finished, southbound 101 traffic will be rerouted onto the completed northbound deck at the 280 interchange. Caltrans revised its construction plan to reduce the traffic impact of construction while stay-at-home measures are in effect and minimize the need for local road detours.
What are the expected noise, light, dust, and vibration impacts of construction? How is Caltrans working to minimize those impacts?
Caltrans is taking several measures to limit the effects of construction. While the response to COVID-19 has reduced traffic, it also means that nearby residents will be home during the 24/7 construction. Construction measures include:
- Removal of the existing bridge beck by sawing away section by section instead of jackhammering to reduce noise, dust, and vibrations. Some jackhammering is necessary to demolish structures i.e. median barrier.
- The use of light balloons where possible. Light towers will focus light down on the worksite, not out into the surrounding neighborhood.
- By replacing the deck rather than rebuilding the entire bridge, we in will not only reduce construction noise and vibrations, but we are able to use lighter equipment that will be quieter as it travels to the site.
This project is 24/7 so there still be noise at night even though measures are being taken to perform as much noisy work during the daytime.
Will pedestrian access be impacted?
The project is planning to provide 10-foot wide access along westbound Alemany that will be open to bicycles and pedestrians.
Will there be a noise compliance monitor on site?
The lead engineer on site will be responsible for monitoring noise and working with the construction crews to minimize noise whenever possible. That said, we know that portions of this project will be noisy and we thank you in advance for your patience.
Will businesses be open?
Yes, San Bruno and Bayshore businesses and the Alemany Farmers’ Market will be open.
Is there a possibility of power and water disruptions?
No, we do not anticipate any power or water disruptions to the surrounding neighborhood as a result of this project.
Where are workers parking?
Workers will park at the Caltrans Maintenance yard on Rickards Street.
Where is equipment being staged?
Equipment is being staged in an area adjacent to the bridge repair area between Alemany Eastbound and Westbound.
How will the removed sections of bridge deck be collected?
Debris will be trucked out to local recycling center. None of the material being removed is toxic.
Why is this work continuing under the shelter-in place-order?
The U.S. 101 Alemany Project is part of continuing Caltrans’s essential work to maintain more than 50,000 miles of California’s highway and freeway lanes. In response to Governor Newsom’s Executive Order N-33-20 classifying the transportation sector as “Essential Critical Infrastructure,” Caltrans is moving forward on the project to help pave the way for a fully open U.S. 101 when we emerge from the health and economic crisis of COVID-19.
How many people are expected to work on this construction project?
There will be 80-100 people on the Meyers &Sons Construction team and 20 Caltrans employees overseeing the work.
How can the public get more information, ask questions not included here, or register complaints or concerns about the project?
The project webpage (101alemanyproject.com) will be updated with new information over the course of the project.