Plan to relieve traffic congestion between Vallejo and Marin raises environmental concerns

SACRAMENTO –  A proposed bill by state Assemblywoman Lori Wilson would expedite a project to widen Highway 37 between Vallejo and Marin County​​ by loosening California environmental laws designed to prevent harm to several protected species.

Project proponents say that the bill, AB 697, strikes a balance by providing the long awaited quality of life improvements for working class commuters and ensuring that any impacts to protected species are minimized and mitigated. 

“State Route 37 is the most frustrating traffic choke point in the Bay Area,” Wilson said. “Equity is at the forefront in terms of this project,” because many people commute to Sonoma and Marin counties for lower or moderate income jobs from areas like Vallejo where housing is more affordable.

However, a number of environmental organizations and climate action groups have expressed opposition to the bill, arguing that the legislation will erode environmental laws and lead the state in the direction of highway expansions rather than toward transit-oriented communities and affordable housing.  

Highway 37 connects I-80 to U.S. 101 and narrows to one lane in each direction as it traverses wetlands along the edge of San Pablo Bay. With more than 30,000 daily users, the highway is heavily congested during commute hours and sections are prone to flooding. 

The flooding problems are expected to increase with climate change and rising sea levels. At the highway's current level, it will face high flood risks after 2040 and portions of the roadway will be inundated by 2050, according to Caltrans. 

A project to elevate the highway is in the planning process but construction is still decades away due to its complexity and cost, projected to be as much as $11 billion. The project includes an option to expand SMART railway service across the bay alongside Highway 37, but a more northerly route is also under consideration.

To provide near-term traffic relief, a group of state agencies, including the Metropolitan Transportation Commission, Caltrans, California Natural Resources Agency, the Department of Fish and Wildlife and San Francisco Bay Conservation and Development Commission developed a plan for an additional interim project that would widen the highway to four lanes with minor height increases to certain portions of the roadway.

Caltrans officials estimate that interim highway widening will cost $500 million, which includes tens of millions of dollars in restoration projects to mitigate the habitat impacts of the project and to increase the ability of the wetlands to act as a sponge, reducing the effects of sea level rise. 

The California Transportation Committee approved a new $4 toll, collected in both directions, to pay for the necessary construction in 2023. The interim widening project would add a car pool or high occupancy vehicle lane in each direction which would not be tolled. 

Currently there is no bus service on the corridor because congestion on the highway makes regular scheduling difficult. The high occupancy vehicle lanes are intended to reduce traffic by allowing convenient and low-cost transit options for those who can commute by bus or carpool.  

The restoration elements include a project to lengthen the Tolay Creek bridge and open the creek’s water channel to increase tidal flows that will facilitate the restoration of wetland areas north of the highway. Restoration projects are also planned for Mare Island bayside wetlands known as the East Strip Marsh.

However, the project faces a major regulatory hurdle because it will disturb the habitat of the salt-marsh harvest mouse, the California Ridgway’s rail, the California black rail and the white-tailed kite, which are on a state list of 34 fully protected animal species. 

The California Department of Fish and Wildlife is prohibited from issuing permits that allow killing or harming fully protected species unless specific criteria are met. 

A 2023 state law, SB 147, expanded the criteria to include water infrastructure projects, solar and wind energy and transportation projects. However the law specifically excluded transportation projects that “increase highway or street capacity for automobile or truck travel.”

Wilson’s bill would create an exception specifically for the Highway 37 interim project. 

Caltrans officials estimate that construction could begin in 2026 with the opening of the new road projected for 2029. But that estimate is reliant on the passage of AB 697, which would allow for a 7-month construction window. 

According to Caltrans spokesperson Bart Ney, without the legislation, construction on the project would be limited to about two months out of the year to avoid mating and nesting periods when the protected species are vulnerable. 

“This would take our crews beyond 5 years to construct the project and more than double the current construction cost estimate.” Ney said in an email. “The increase in costs would be due to the need to use multiple crews, adding more overtime, and other methods needed to expedite the project.”

U.S. Rep. Jared Huffman, who represents Marin and the coastal region, has criticized the bill, saying it would make it easier to carve out exceptions to the state’s environmental laws for development projects.

“If you're going to create an endangered species carve out for this freeway widening, you pretty much have to do the same thing for every freeway widening in California,” Huffman said. There's no reason that this one would deserve special treatment, and that's a major policy change.”

Wilson said if legislators were to use the language of the bill to create additional exemptions it is unlikely that other projects would be a good fit. “They would have a high bar, we're being very mindful to keep in the environmental protections,” she said. 

Caltrans spokesperson Vince Jacala said that regardless of whether the bill passes biologists will conduct surveys to identify habitat that could be disturbed by the construction activities and if a protected species is discovered, the agency will consult with the Department of Fish and Wildlife before proceeding. 

"If a salt marsh harvest mouse is discovered, work would pause, and the animal would be allowed to leave the area on its own,” Jacala said in an email. 

However, it is not only the protections for specific species that opposition groups are concerned about. The main point of contention relates to the interim project’s limited lifespan combined with its half-billion dollar price tag. 

“It's going to make climate change worse on a corridor that Caltrans has said in their own documentation could be underwater because of sea level rise as soon as 2040,” said Jeanie Ward-Waller, an advocate with the climate strategy group Transform.

According to Ward-Waller, there is well established evidence that widening roads leads to an increase in vehicle miles traveled. The effect is known as induced demand which means that driving patterns shift when new capacity is added to a roadway and congestion quickly returns.

But a draft environmental impact report did not forecast a significant increase in vehicle miles traveled and carbon dioxide emissions once the project is complete. Those projections rely on the tolling and the high occupancy vehicle lanes that will allow transit service on the route to limit vehicle trips.

Bay Conservation and Development Commission Executive Director Larry Goldzband said that the project could actually be restorative for wetlands north of the roadway. Highway 37 acts as a barrier preventing tidal flows to the wetlands, but  widening the Tolay Creek bridge would allow more efficient tidal flows, restore 225 acres of wetlands and improve the ecosystem’s resilience to future changes.

“We need to start restoring those baylands ASAP, now, in order to beat rising sea level, because if we don’t they are simply going to drown.” Goldzband said in a November SR 37 Policy Committee meeting.  

Josh Quigley of Save the Bay said that even though the interim project does offer restoration benefits, raising the highway will provide the best opportunities to restore wetland habitat.

“I agree that the emphasis should be on maximizing the amount of nature based sea level rise adaptation in the North Bay,” Quigley said. “But, the interim project is not accelerating the maximum extent of sea level rise adaptation capacity by opening up the maximum amount of restorable wetland areas, it's continuing to build a larger berm, which is going to be an ongoing obstacle to further restoration.”

Thomas Bartee, who has been involved in the State Route 37 Policy Committee planning discussions as a former district director for Sen. Bill Dodd, said that the problem with skipping the interim project and moving ahead with elevating the highway is that it will take 15 years to fund and build the larger project while “people are suffering everyday waiting two hours on Highway 37.”

Wilson’s bill is scheduled for a final vote in the Assembly on Thursday and if it passes it will move on to the senate.

“This project allows us to improve the quality of life of the people who live in the area while protecting the environment,” Wilson said. “I look forward to getting this bill across the finish line so we can provide relief.”