State officials released new details on a plan to upgrade and eventually rebuild one of the Bay Area’s most vulnerable and traffic-congested suburban thoroughfares: the Highway 37.
By 2040, rising sea levels threaten to routinely flood the 21-mile highway used daily by tens of thousands of commuters, according to Caltrans.
After years of discussion, the state is beginning to study several options to rebuild or reroute the highway, including raising the existing road, rerouting it farther north, and even building a new bridge over San Pablo Bay.
While the reconstruction project would take decades, Caltrans is also proposing a plan in the coming years to widen a bottleneck section of the freeway that is slowing traffic for more than an hour in some cases.
“State Route 37 is a beautiful but unique corridor with many serious challenges,” Sen. Bill Dodd, D-Napa, said during a presentation on the plans Wednesday. “However, I truly believe that the solutions to these short-term and long-term challenges can be a model for the rest of the country and of course the state of California.”
Caltrans has developed eight concepts for how it might reroute or rebuild Highway 37 in the coming decades. Options range from diverting the highway to other routes further north; maintaining the route by raising the highway or building a new system of dykes; or building a new bridge north of San Pablo Bay connecting Marin to Solano County. The plan also calls for the construction of a separate cycle and pedestrian path along the new corridor as well as the integration of public transport options such as bus lines, trains and ferries.
the to studyscheduled for completion in late summer or early fall, will help narrow down the options, which will then undergo a full environmental review.
To address traffic issues, Caltrans proposes to begin widening a 10-mile section of the freeway from Sears Point to Mare Island in 2025. The bottlenecks section from two lanes to one lane each, increasing times travel time of 30 minutes during the morning commute and up to 80 minutes during the afternoon commute, according to the Metropolitan Transportation Commission, the Bay Area’s primary transportation planning agency.
To reduce travel time, Caltrans wants to add at least one carpool lane that would also allow transit buses to use the freeway for the first time. Caltrans presented four construction options on Wednesday that would cost between $256 million and $415 million and be paid for by the highway’s toll.
A draft environmental review of the proposals is undergoing public review and comment until February 28.
One option would be to add a moveable barrier to the freeway — similar to the one used on the Golden Gate Bridge — to move the extra carpool lane during rush hour west and east. The project would cost approximately $256 million, including an additional $2 million per year for maintenance and personnel costs.
The second option would be to add a third lane to the freeway, which would be moved west or east depending on peak times. This option would cost approximately $306 million.
The last two options would widen the freeway to four lanes to add a carpool lane in each direction. One option would have shoulders of just 4 feet, while the other option would have an 8-foot shoulder and widen the Sonoma Creek Bridge. This fourth option would also be the only one to allow access to bicycles. These options would cost between $325 and $415 million.
Project consultant Jeff Zimmerman said electronic tolling would be added to the freeway to help pay for the project and the eventual rerouting or rebuilding of the freeway.
Anne Richman, executive director of the Transportation Authority of Marin, said the two project studies represent an important milestone after years of planning and will also help secure future funding.
“We are optimistic that state support and the influx of federal funding from the Infrastructure, Investment and Jobs Act will help these critical regional projects move forward in design and construction,” said Richman.
More information on both projects can be found online at bit.ly/3sir8NJ.