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Highway 101 Construction Projects

Highway 101 construction may affect traffic to/from SFO. Please plan accordingly


Alemany Project

On April 24, Caltrans will begin construction work to replace the U.S. 101 bridge deck at San Francisco’s Alemany Circle. Construction is expected to be completed on April 30.

During this timeframe, traffic leaving SFO and typically using northbound 101 to access San Francisco or the Bay Bridge should take the I-380 exit to northbound I-280 to the northbound 101 connector. This will connect motorists immediately after the Alemany Deck Replacement onto northbound 101 to downtown San Francisco and the Bay Bridge. A secondary detour route from Northbound 101 to Northbound I-280 is recommended for certain destinations in the southeastern part of the City. View map.

Additional traffic detours may also be in place during the construction period. Please refer to Caltrans' US 101 Alemany Project information for detour updates.

San Mateo 101 Express Lanes Project 

Caltrans is constructing express lanes on U.S. 101 from Redwood City to I-380 in South San Francisco.  During the project, freeway lane and ramp closures will occur on northbound and southbound U.S. 101. At times, lanes and exits at or near SFO will be impacted. Most work is scheduled to take place between 8:00 p.m. and 6:00 a.m., Sunday through Thursday. Closures will be marked by roadway signage, with detour signs posted. 

Please note that the southbound 101 Domestic Terminal On Ramp to the Airport will be closed on Monday, April 20 from 8:00 p.m. to 5:00 a.m. Detours will be in place.

Please view Caltrans’ construction schedule for closure information and plan any travel to/from SFO accordingly.