County of Marin - News Releases - Muir Woods Road

For Immediate Release
April 04, 2017

Alternatives to be Evaluated for Muir Woods Road

One of Mount Tam’s primary roadways enters next stage of rehabilitation

San Rafael, CA – The Marin County Department of Public Works (DPW) has been working with several federal and state agencies on an extensive rehabilitation project for Muir Woods Road, a heavily used artery for traffic over Mount Tamalpais.

Road shoulder deterioration and erosion is shown along Muir Woods Road.Shoulder deterioration and erosion exists along Muir Woods Road.

In a follow up to the November 2016 public scoping meeting, a second public meeting will take place at 6 p.m. April 18 at the Muir Woods Park Community Association, located at 40 Ridge Avenue, Mill Valley. DPW staff will present five project alternatives developed to address the road’s deteriorating condition.

Improvements to the 2.4-mile section of road, including fixing a substandard bridge, would allow for safer access to state and federal lands, including Muir Woods National Monument and Muir Beach. Due to decades of extensive use and weather damage, the road’s structural integrity has degraded at seven distinct locations, to the extent of restricting traffic to a single lane at one location. Redwood Creek’s embankment, which is parallel to the road, has eroded significantly, resulting in slope failures and the loss of functionality at key culverts. The issues were exacerbated during the recent storm season because of the road’s deteriorated drainage capabilities.

Preliminary engineering, aided by input from last fall’s public scoping, has resulted in five possible options for addressing Muir Woods Road and the bridge over Redwood Creek. The alternatives, to be discussed during the April 18 meeting, include engineering and environmental choices such as roadway width adjustments, bicycle safety considerations, and a conversion to a one-way system, as well as degrees of hillside rehabilitation.

Following the meeting, an environmental assessment will be conducted to evaluate the potential impacts that the project will have on the surrounding ecosystem. Pending completion of the study, the construction would start in 2019.

Marin County has been approved for more than $5.2 million in grant funds for the project through the Federal Lands Access Program (FLAP). The cost of the rehabilitation project is estimated to be $5.9 million for the roadway and $2.2 million for the bridge, of which the FLAP grant covers 88.5 percent. The County of Marin will commit local funds for the remaining 11.5 percent.


RJ Suokko
Senior Civil Engineer
Public Works

3501 Civic Center Drive.
San Rafael, CA 94903
(415) 473-4399
Email: RJ Suokko
DPW webpage