Sir Francis Drake Boulevard Bridge Replacement Project
The County of Marin has received federal funding to replace local bridges that have been identified as structurally deficient and functionally obsolete. Sir Francis Drake Boulevard over Olema Creek is one of the bridges identified for replacement and a project has recently been initiated to conduct environmental studies and to begin design work. Protecting the riparian habitat, safeguarding the adjacent Point Reyes National Seashore, and minimizing disturbance during construction will be high priorities for the project.
Sir Francis Drake Boulevard Bridge is located just west of Highway 1 between the community of Point Reyes Station and Inverness. The bridge is just upstream of the confluence of Olema and Lagunitas Creek. Sir Francis Drake Boulevard is a narrow two-lane roadway that provides connectivity between the community of Inverness, as well as, the Point Reyes National Seashore and Point Reyes Station.
The existing bridge was built in 1930 and is a three-span, reinforced concrete slab structure. The bridge needs to be replaced for the following reasons:
- The structure has reduced load carrying capacity.
- Erosion at the easterly pier has resulted in exposure of the pier footing.
- The site is adjacent to the San Andreas Fault and the existing bridge was not designed to withstand the high seismic forces and liquefaction that are expected to occur during an earthquake.
The project improvements are anticipated to extend from 500 feet along Sir Francis Drake Boulevard form either side of Olema Creek.
To facilitate construction, Sir Francis Drake Boulevard may need to be temporarily closed to traffic. If a road closure were to occur, traffic would be detoured to Bear Valley Road and Highway 1. Access to residential properties will still be maintained at all times.
Alternatively the project improvements may be constructed in stages while maintaining a single lane of traffic through the project site. However, the overall duration in this scenario will take approximately twice as long.
The project is 88.5% federally funded through the Highway Bridge Program. The federal funds are being administered through the Caltrans Local Assistance Program. The remaining 11.5% is locally funded.
The anticipated project timeline is as follows:
|Begin Environmental Studies and Preliminary Engineering
|Initiate Detailed Design
|Conclude Environmental Review
||Final Design Plans
Note: Timing will be coordinated to avoid the construction period of the Green Bridge on Highway 1.
For information about the “Green Bridge” on Highway 1 just south of Point Reyes Station use the link below. The Green Bridge project is within the State right-of-way and thus that project is being managed by Caltrans. To be directed to their project webpage follow the link:
Community outreach and engagement are fundamental to developing the design of the new bridge. The project development process will integrate the community’s vision and resident needs so that they are reflected in the final design. Public meeting(s) will be scheduled and advertised at a later date.
For more information, contact Chris Good, Associate Civil Engineer.