Photo of wildlife bridge over a freeway

California plans on world’s largest wildlife bridge

What's Happening

In April, conservationists and state officials alike celebrated the groundbreaking construction of a $90 million dollar wildlife bridge, the Wallis Annenberg Wildlife Crossing, in Los Angeles. The 210 foot long, 170 foot wide structure will span the 10-lane U.S. Highway 101 when completed, connecting two sections of the Santa Monica mountains – making it the largest bridge of its kind on Earth. Caltrans is overseeing the project, in collaboration with the California Dept. of Fish & Wildlife and the National Park Service, expects that the bridge will avoid thousands of wildlife collisions. More and more wildlife bridges are being built across the country, and, while this bridge was funded mostly by private donations, public investments in animal-friendly infrastructure (like funds in the Governor’s 2022 proposed state budget) may set the stage for larger-scale construction of wildlife bridges throughout California.  

Here's Our Take

The UC Davis Road Ecology Center, led by Dr. Fraser Shilling, is at the forefront on research surrounding both the impacts of our transportation system on habitat fragmentation and animal movement patterns, and on solutions to improve habitats and road safety. Regarding the Wallis Annenberg Wildlife Overpass, UC Davis researchers at the Road Ecology Center conducted a series of studies on the impacts of light and noise on wildlife behavior. They found that light- and noise-sensitive wildlife (e.g., mountain lions) are more likely to use crossings if the surrounding area is darker and quieter. From these studies, the researchers were able to provide specific recommendations for the placement of berms and barriers near the crossing, effectively designing the landscape to minimize light and noise from traffic on the highway.

For a more in-depth take on the fascinating work of the Road Ecology Center for the Wallis Annenberg wildlife crossing, check out this UC Davis Transportation and Climate Blog post.

Many projects like these require years of planning and preparation, and getting over the reticence and institutional inertia in changing transportation infrastructure funding and construction is quite a heavy lift. Californians are far past ready for these kinds of projects however, and with researchers like Dr. Shilling leading the way, we already have a solid grasp about what is happening, and more importantly, how to design and build solutions for wildlife and for people.