SR 131 Capital Preventive Maintenance

Project Overview

Caltrans District 4 (Bay Area) reached 100 percent design in the State Route 131 (SR-131) in the Capital Preventive Maintenance Project in the town of Tiburon. Phase 1 is scheduled to go into construction in mid- to late-summer of 2026.

The purpose of the project is to improve serviceability and ride quality on SR-131 and restore existing drainage systems to reduce the potential for highway flooding and to increase the safety for the public.

In addition, the project will enhance and complete streets and support active modes of transportation by bridging a gap in the transportation network and improve bicycle access throughout the area.

The location is approximately 1,000 feet west of US-101 interchange to the Tiburon Boulevard/Main Street intersection.

The project is broken down into three segments: The western segment includes Class I, II and IV bikeways, intersection modification as well as curb ramps, pedestrian refuge islands and sidewalk modifications. The central segment includes Class II and IV bikeways and intersection modifications. The eastern segment includes intersection modifications.

The Draft Environmental Document (DED) for the project was released and Caltrans held a public comment period from Sept. 29 through Nov. 3, 2023. The link to the DED can be found here: https://bit.ly/3FoHdsj

Project Schedule for Phase 1 of SR-131 CAPM project

The final environmental document was released in January of 2024.
The final design phase was complete in early 2026.
Construction is targeted to begin in September 2026.
The project is scheduled to be completed in the winter of 2027.

Project Contact

Matt O’Donnell
Marin County Public Information Officer
Email: matt.odonnell@dot.ca.gov
Phone: (510) 852-5113