Lawsuit Challenges California Highway Expansion Project

ALAMEDA COUNTY, Calif., May 30, 2024 — Environmental groups filed suit today to challenge the Yolo I-80 highway expansion project. Citing a flawed environmental impact report that understates the true effects on traffic, climate and air quality, the groups petitioned the courts to require Caltrans to redo the analysis of the project and fully mitigate its environmental harms.

The project to expand I-80 from Davis to Sacramento through the Yolo Bypass Wildlife Area would increase greenhouse gas pollution and harm sensitive wildlife.

NRDC (Natural Resources Defense Council), representing the Planning and Conservation League, along with the Center for Biological Diversity, raised several issues in its complaint.

First, Caltrans improperly chopped this project into two pieces to use funding in illegitimate ways and obscure environmental impacts, as documented by a Caltrans whistleblower. The first project, already underway, is using maintenance-only transportation dollars to strengthen the shoulders of the highway so they can accommodate heavy vehicle travel. The second project would restripe the road to accommodate the additional lane of traffic in each direction.

“This is a classic example of Caltrans hiding the ball about the true impacts of these projects,” said Carter Rubin, director of state transportation advocacy at NRDC. “It’s time for Caltrans to own up. After decades of expanding our freeway system, they’ve only made traffic worse. Californians deserve real solutions for getting out of traffic, not more false hope from Caltrans.”

Second, Caltrans used inappropriate and flawed models to evaluate alternatives and significantly overstated the traffic benefits of the alternatives that add new vehicle lanes.

“The congestion and smog we suffer from today are consequences of yesterday’s bad planning, and this project will fuel tomorrow’s pollution problems,” said J.P. Rose, policy director at the Center for Biological Diversity. “Caltrans completely missed the mark by approving a freeway expansion that will only put more pollution-spewing cars on the road. Let’s take the climate crisis seriously and find alternatives that don’t make a mockery of California’s climate goals.”

Today’s suit, filed in Alameda County Superior Court, also states that Caltrans did not fully disclose and adequately analyze the project’s impacts, because the environmental impact report relied on flawed modeling that led to significant undercounts of vehicle miles traveled, traffic impacts, greenhouse gas emissions, air quality and energy impacts.

“California needs to quit its addiction to ever-expanding highways if we are ever going to achieve our greenhouse gas reduction mandates,” said Matt Baker, policy director at the Planning and Conservation League. “This change needs to begin with Caltrans fully accounting for and mitigating its projects’ impacts.”

Finally, Caltrans failed to adequately mitigate the additional driving that the project will cause, even though there are feasible mitigation measures. Specifically, the project would mitigate only half the vehicle miles traveled that it would cause, by Caltrans’s own count, and an even smaller percentage when correcting for Caltrans’s modeling flaws.

The Sierra Club and the Environmental Council of Sacramento (ECOS) are also expected to file suit to challenge the Yolo I-80 highway expansion project.


The Center for Biological Diversity is a national, nonprofit conservation organization with more than 1.7 million members and online activists dedicated to the protection of endangered species and wild places.

NRDC (Natural Resources Defense Council) is an international nonprofit environmental organization with more than 3 million members and online activists. Established in 1970, NRDC uses science, policy, law and people power to confront the climate crisis, protect public health and safeguard nature. NRDC has offices in New York City, Washington, D.C., Los Angeles, San Francisco, Chicago, Beijing and Delhi (an office of NRDC India Pvt. Ltd).

Planning and Conservation League was founded in 1965 to protect and restore California’s natural environment, and to promote and defend the health and safety of Californians through legislative and administrative action.


https://biologicaldiversity.org/w/news/press-releases/lawsuit-challenges-california-highway-expansion-project-2024-05-30/