101 Express Lanes Project Update

Caltrans is constructing express lanes on U.S. 101 from the Santa Clara/San Mateo County line to I-380 in South San Francisco. Construction is expected to be completed in 2022.
Construction Update – Week of April 26
Construction activities on U.S. 101 will include; continued work on the sound walls on Bayshore Boulevard in San Mateo (both from Newbridge Avenue to just past Dakota Avenue and from Dore Avenue to East Poplar Avenue), removing guard rails, installing temporary lighting, traffic signals on ramps, temporary detour signs, temporary traffic detectors, electrical service work, drainage systems, a new sewer system, and other related construction activities. Most of the work will occur on the freeway lanes, shoulders, and ramps, while the sound wall and sewer work will occur on city streets adjacent to U.S. 101.
Freeway Lane Closures: Nightly freeway lane closures will occur on northbound and southbound U.S. 101 from 7:00 p.m. to 5:30 a.m., Sunday through Thursday nights. Due to low traffic volumes, project related traffic delays are anticipated to be minimal. Caltrans will continue to monitor traffic delays and adjust as necessary.
Freeway Ramp Closures: Temporary ramp closures will occur during the night in/near Redwood City, San Carlos, Belmont, San Mateo, Foster City, Burlingame, Millbrae, San Bruno, and South San Francisco, and during the day in San Mateo. Ramp closures could occur on both the northbound and southbound directions of the freeway. However, consecutive interchanges for northbound and southbound ramps will not be closed at the same time.
Nighttime ramp closures:
  • Will be displayed at changeable message signs within the construction zone
  • will last three to ten hours
  • will begin after 7:00 p.m. and reopen by 6:00 a.m.
  • will have detour signs posted
Short-term nighttime ramp closures are possible this week (Sunday though Thursday night) at the following locations near Redwood City:
  • Eastbound/Westbound Whipple Avenue On Ramp
  • Northbound/Southbound Whipple Avenue Off Ramp
  • Northbound Holly Street Off Ramp
  • Eastbound/Westbound Holly Street On Ramp
For a full list of closures, click here.
For questions during construction, contact the Caltrans Public Information Officer: Alejandro Lopez at (510) 286-4948 or .