101-express-lanes-overnight-closures-feb-2021

 

Overnight Closures on U.S. 101 - Week of February 28th from 11:00 PM to 4:00 AM

As part of the San Mateo 101 Express Lanes Project, Caltrans will be replacing five overhead sign structures (that span the width of one side of the freeway, from the shoulder to the median) on U.S. 101. The first step of this work is to safely remove the sign structures and install temporary orange roadside signs along the freeway shoulder. Due to the large size of these sign structures, it is necessary to close one direction of the freeway at a time between Millbrae Avenue and South Airport Boulevard, for five nights.

 

Sign structures are being replaced to make room for the new express lane throughout the corridor.

highway sign across highway 101

Overnight closures on U.S. 101 will occur each night during the week of February 28th (from 11:00 PM to 4:00 AM), when traffic volumes are usually light.

Motorists are advised to be familiar with the proposed detour routes and allow extra travel time.  

  • Southbound U.S. 101 from South Airport Boulevard to San Bruno Avenue is anticipated to be closed overnight on Sunday, February 28th, Monday, March 1st, and Tuesday, March 2nd to safely remove three sign structures.
  • Northbound U.S. 101 from Millbrae Avenue to San Bruno Avenue is anticipated to be closed overnight on Wednesday, March 3rd and Thursday, March 4th to safely remove two sign structures.

Closure locations and times will be displayed on changeable message signs at least one week in advance.

Motorists will be directed to exit the freeway in advance of the closed freeway sections, and detour signs will be in place to clearly guide them through city streets until they get back on the freeway. Detour routes have been carefully selected with input from local jurisdictions to minimize impacts to nearby residents. See the detour maps below for the exact detour routes.

At no point will both the northbound and southbound directions of U.S. 101 be closed at the same time.

All construction activities are subject to change without notice

Learn More

  • Check out the Project’s video on the freeway closures and detour routes. Click here to watch!
  • Access real-time traffic conditions on the Caltrans QuickMap: quickmap.dot.ca.gov
  • Sign up for weekly updates by emailing with the subject line “weekly” to 101express@dot.ca.gov
  • Follow @CaltransD4 on Twitter for the most update to date information on full freeway closures and other construction activities planned each week. 

photo of crane lifting 101 sign structure | photo of mounted 101 sign structure

Detour Routes

Southbound U.S. 101 from San Mateo Avenue to San Bruno Avenue (Overnight February 28th, March 1st, and March 2nd from 11:00 PM to 4:00 AM)

Southbound Detour Route: 

Southbound 101 closure map

 

During southbound closures, anticipated to occur overnight February 28th, March 1st, and March 2nd from 11:00 PM to 4:00 AM, motorists will be directed to exit southbound U.S. 101 at the Produce Avenue/South Airport Boulevard Off-Ramp, in the City of South San Francisco. Motorists will then be guided by detour signs to South Airport Boulevard and diverge at the South Airport Boulevard/I-380 intersection. Motorists may choose to return to Southbound U.S. 101 by way of the (SFO Airport) San Jose On-Ramp from San Bruno Avenue, or access other destinations. Northbound traffic will be unaffected.

During this closure, the following freeway ramps will be closed:

  • Southbound U.S. 101 On-Ramp from Produce Avenue
  • Southbound U.S. 101 Off-Ramp to Westbound I-380
  • Southbound U.S. 101 Off-Ramp to San Bruno Avenue/SFO/ North Access Road

Northbound U.S. 101 from Millbrae Avenue to San Bruno Avenue (Overnight March 3rd and March 4th from 11:00 PM to 4:00 AM)

Northbound Detour Route:

Northbound 101 closure map

During northbound closures, anticipated to occur overnight March 3rd and March 4th from 11:00 PM to 4:00 AM, motorists will be directed to exit northbound U.S. 101 at the Millbrae Avenue Off-Ramp, in the City of Millbrae. Motorists will then be able to choose between two detour routes, diverging east and west, to either return to northbound U.S. 101, or reach their destination. The detour route on El Camino Real will cross through the cities of Millbrae and San Bruno, while the detour route on McDonnell Road will keep drivers on the frontage road adjacent to SFO Airport. Southbound traffic will be unaffected.

During this closure, the following freeway ramps will be closed:

  • Northbound U.S. 101 On-Ramp from Millbrae Avenue
  • Northbound U.S. 101 On-Ramp from SFO
  • Northbound U.S. 101 Off-Ramp to San Bruno Avenue/Westbound I-380 Connector

Upcoming Freeway Closures

Northbound U.S. 101 from East Hillsdale Boulevard to SR-92 is also anticipated to be closed in order to remove a sign structure in this area. This closure is tentatively planned for April 2021. Check back for more information.

To install new sign structures, where sign structures were removed, additional freeway closures will need to occur. Closures of the below sections of freeway are currently scheduled to occur in late 2021 to complete installation of new sign structures. Check back for more information.

  • Northbound U.S. 101 from Millbrae Avenue to San Bruno Avenue
  • Southbound U.S. 101 from San Mateo Avenue to San Bruno Avenue
  • Northbound U.S. 101 from East Hillsdale Boulevard to SR-92