A ‘Grand Bayway’ is envisioned for Highway 37

A massive, two-decade, $1 billion project to widen Highway 101 through Sonoma County is wrapping up now that officials have secured funding for the last piece of the project in Petaluma. Transportation officials are now beginning in earnest to turn their attention to the next big regional infrastructure challenge: a redesign of Highway 37, an effort they acknowledge could take as long and cost more than the Highway 101 project.

North Bay leaders have been meeting regularly for the past several years, imagining the future of Highway 37, a major transportation route along the top of San Pablo Bay, but one that is prone to flooding as sea levels rise and congestion as the population increases.

“I think it will be the next big regional project we will have to address,” said Petaluma Councilwoman Kathy Miller, a representative on the Sonoma County Transportation Authority. “It’s going to be complicated and expensive.”

One bold concept for Highway 37 emerged out of a Bay Area design contest, Resilient By Design. The winning entry came from a team led by TLS Landscape Architecture, which envisioned a sweeping causeway with rail access and pedestrian boardwalks.

Designers have pitched the proposal, called The Grand Bayway, in various North Bay cities recently. Decision makers are generally impressed with the concept, but realized that it is well beyond their funding level.

“I’ve looked at the drawings and thought, ‘Wouldn’t that be cool,’” said Supervisor David Rabbitt, who leads the committee of transportation officials studying the options. “But the money, even for the right of way, the dollars don’t fall in line with that particular project.”

The current highway between Sears Point and Vallejo is a two-lane bottleneck on a low levee system that is prone to flooding. The Grand Bayway project would move the right of way to the north, eliminate the levees to allow for bay water to flow more naturally, and make the road a four-lane elevated causeway.

It includes elevated trails for walkers and cyclists to enjoy the wetlands.

Kushal Lachhwani, a project designer with TLS Landscape Architecture, who worked on The Grand Bayway, said it would fix the flooding and traffic problems, but also serve as a statement piece for the North Bay.

“It’s an opportunity not just to solve the flooding, but to add an iconic front door to the North Bay,” he said. “It could be like the Golden Gate Bridge.”

Lachhwani said the team did not put a price tag on construction of their design - it is more conceptual, a think piece that officials could use to guide their policy discussions. He said the team has been in communication with the committee studying Highway 37 about building parts of the design.

“Realistically, the project can’t be completed in one go,” he said. “It would be completed in phases.”

The attention to Highway 37 comes with additional funding. A bridge toll increase that voters approved in June will provide $100 million for Highway 37 improvements, and Rabbitt said officials are discussing how best to spend the money.

The corridor has been divided into three segments - from Highway 101 to Sears Point, which is prone to flooding; Sears Point to Mare Island, which is prone to flooding and traffic; and Mare Island to Highway 80, which has congestion issues. The middle section through the wetlands is the top priority, officials say.

As part of the discussion, officials are considering turning the highway over to the Bay Area Toll Authority, which operates other Bay Area bridges. Tolls from other bridges could build the causeway, and tolls from Highway 37 could pay back the cost.

While construction of the causeway is still several years away, the first Highway 37 improvements could come much sooner. Caltrans has initiated a project that would add a two-lane roundabout at Highway 37 and Highway 121, a major bottleneck, especially during events at the nearby Sonoma Raceway.

“This is a project we are very interested in,” said James Cameron, director of projects and programming at the Sonoma County Transportation Authority. “It’s a near term solution.”

The project initiation document is the first phase in a lengthy Caltrans project that includes environmental review, relocating utilities and obtaining right of way. If all goes well, Caltrans could fund the construction phase of the new roundabout in 2020, Cameron said.

Highway 37 was built between 1917 and 1928, and has changed little since then. Though a redesign will likely cost more than $1 billion, and the timeline remains unclear, the new roadway will likely be drastically different.

“It’s an interesting exercise,” Rabbitt said. “Every now and then you have to look at, if you did it all over again, what would it look like.”

(Contact Matt Brown at matt.brown@arguscourier.com.)