Skip to main content

San Mateo 101 Express Lanes Closure Project

Caltrans is scheduled to implement full Highway 101 North and South closures near the Airport starting Sunday, February 28 through Thursday, March 4, 2021, between the hours of 11:00 p.m. to 4:00 a.m. The full freeway closures are needed to remove five overhead sign structures which span the Highway 101 traffic lanes near the Airport. This work is part of the San Mateo 101 Express Lanes Closure Project which will reduce traffic congestion, encourage transit use and carpooling on Highway 101 in San Mateo County.

During the closures, traffic will be detoured using the Airport’s frontage roads, South Airport Boulevard and El Camino Real as shown in the maps below. 

SB101 map
NB101 map


Caltrans will implement the full Southbound closures from South Airport Boulevard to San Bruno Avenue on the first three nights of the project (Sunday, February 28, Monday, March 1, and Tuesday, March 2). The full Northbound closures from Millbrae Avenue to San Bruno Avenue will be implemented on the last two nights (Wednesday, March 3 and Thursday, March 4). At no point will the Southbound and the Northbound directions on Highway 101 be closed simultaneously.

Closure locations and times will be displayed on freeway overhead signs and changeable message signs at least one week in advance. During the closures, 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 to direct them back onto the freeway.

For additional project updates and information, please refer to Caltrans webpage at: