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The Transportation Authority of Marin (TAM) has begun the planning and environmental phase of a proposed project to construct a direct highway connection from northbound US-101 to eastbound I-580 in Marin County. TAM will complete the environmental analysis to evaluate options and work with the community and stakeholders to select a preferred alternative. 

This project is a collaborative effort between TAM, the California Department of Transportation (Caltrans), and the cities of San Rafael and Larkspur.   

Currently, drivers who wish to access the Richmond-San Rafael Bridge (I-580) via northbound US-101 have to exit the freeway and travel on East Sir Francis Drake Boulevard or across Bellam Boulevard to the bridge entrance.  Having to drive on local streets causes congestion and traffic delays on northbound US 101 and on local streets, including Sir Francis Drake Boulevard and Bellam Boulevard. 

The proposed project will allow vehicles to continue along US-101 northbound onto a new highway connector in San Rafael and merge directly onto I-580 eastbound toward the Richmond-San Rafael Bridge. 


The objective of the proposed project is to reduce congestion and improve traffic flow on NB US-101 and local streets. TAM will accomplish this by providing a direct highway connection from northbound US-101 to eastbound I-580 and the Richmond-San Rafael Bridge. The project will also enhance existing multi-modal (bicycles pedestrian, and transit) connections.   

Bicycle and pedestrian connections will also be improved along Bellam Boulevard.  Additional benefits associated with this project include more efficient regional and local bus routes in the project vicinity and other project amenities, such as landscaping and streetscape beautification.  


TAM is working to reduce bottlenecks and back-ups on eastbound I-580 as it approaches the Richmond-San Rafael Bridge. In collaboration with the Metropolitan Transportation Commission (MTC), Caltrans and Contra Costa Transportation Authority, a third lane has been opened on the bridge to help alleviate heavy trafficThe third lane now extends from the existing I-580 onramp from East Sir Francis Drake Boulevard on to the bridge.   

As part of the new US-101 to I-580 connector project, a new auxiliary (extra) lane will be built along eastbound I-580 from the new entry point to the existing onramp from east Sir Francis Drake Boulevard. This will allow drivers to use three lanes from the new connector all the way onto the bridge and into Richmond


This project received voter support for funding in the local Marin Transportation Sales Tax Measure AA, approved in November 2018. TAM also advocated for this project to be included in Regional Measure 3which was approved in June 2018. 

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(Click to enlarge)

A Stakeholder Working Group has been created to provide community input to the project team. The SWG provides a forum for the project team to understand community concerns and issues early in the project development process and creates an ongoing communication channel.  The committee is comprised of volunteers representing a variety of interests in Marin County.

View the Membership List

Upcoming Meetings

SWG Meeting # 1 – Monday, June 29, 2020 at 3pm – SWG Introductions and Overview – Agenda and view the presentation and notes

SWG Meeting #2 – Tuesday, July 21, 2020 at 2pm – Project Alternatives and Discussion – Agenda and  view the presentation and notes

SWG Meeting #3 – Tuesday, August 25, 2020 at 3pm – Bellam Boulevard Improvements and Additional Information about Project Alternatives – Agenda and view the presentation and notes

SWG Meeting #4 – Wednesday, January 20, 2021 at 3pm – Equity Considerations –  Agenda and view the presentation and notes

SWG Meeting # 5 – Monday, April 26, 2021 at 3pm – Prior concepts, new and modified alternatives, review of all alternatives – Agenda and view the presentation and notes. To prepare for SWG #6, review the handbook.

SWG Meeting # 6 – Tuesday, May 18, 2021 at 3pm – Provide input on alternatives-  Agenda and view the presentation. Review this handbook for an overview and visuals of the alternatives. View the meeting notes, the summary slides of meeting input and background of funding commitments.

These meetings will be hosted as Zoom webinars with SWG members and the project team as panelists to share information and to allow interaction and input. SWG meetings are open to the public and public comments will be taken at the appropriate times.

Details regarding the meeting agendas and meeting access/log-in information will be posted on the Calendar Page at least 72 hours prior to each meeting.

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Connie Fremier, P.E., Project Manager
Dan Cherrier, P.E., Project Manager
Molly Graham, Public Outreach Coordinator