Caltrans Launches Harbor Bay Bridge Replacement Project


District: 4 – Marin 
Contact: La-Tanga Hopes 
Phone: (510) 715-8865 

Starting Monday, February 1, 2021

Marin County – On Monday, February 1, 2021, the California Department of Transportation (Caltrans) will begin the Harbor Bay Bridge Project in the City of San Rafael.  Using new and innovative construction technology, the project team will perform removal and replacement of the original bridge, located at the northbound off-ramp on US Highway 101.  Additionally, project work will include construction improvements at 2nd and Irwin Street intersection as well.  


There will be a series of lane and full ramp closures throughout the project along with a significant amount of temporary lane shifts.  Motorists are advised to drive with caution and follow all posted directional signs.  Traffic advisories and detour routing options will be utilized to keep the public and all motorists updated, safe, and thoroughly informed throughout the life of the project.  More information about the Caltrans Harbor Bay Bridge Project can be found using the following link:

Standard operational construction hours are Monday – Friday starting at 7AM4PM.  However, some late night and weekend work will be required.  The public will be notified in advance.  

Meanwhile, initial lane and bridge closures will take place in the following stages:

February 1st4th 

  • 3 lane closure from 9PM -11PM
  • Full ramp closure 11PM6AM

February 5th

  • 3 lane closure only from  9PM - 11pm 

February 7th

  • 3 lane closure from 8 PM – 11PM
  • Full ramp closure 11PM –  6AM

Standard traffic control measures will include:  Traffic Cones, Barricades, Crash Cushion Trucks, and portable changeable message signs (PCMS’s).  California Highway Patrol (CHP) will also be on location patrolling the scene and enforcing traffic ordinances.