How wildlife crossings protect both animals and people

Interstate 90 is the longest interstate highway in the United States. Spanning more than 3,000 miles, it connects Seattle in the west to Boston in the east. But it also serves as a huge concrete division. For the animals that live north and south of the interstate, this road has completely destroyed their route.

The U.S. Forest Service and the Washington State Department of Transportation have teamed up to develop a network of “creature crossings” in Washington – overpasses and underpasses designed to provide safe passage for wildlife.

The crossing project, with structures in identified areas where animals are likely to cross, spans 15 miles of I-90 near Snoqualmie Pass, Washington, flanked by large chunks of what is mostly national forest land — habitat for all manner of creatures. , big and small. .

But if animals are protected on both sides of I-90, why does it matter if they’re not connected? “Because we lose genetic variability,” said Patty Garvey-Darda, a wildlife biologist with the Forest Service, “and we gradually start to experience localized extinction and populations get further apart and smaller.”

Across the country, most animals see a busy road and turn around. Some brave people may try to cross, but they run the risk of being run over. A wildlife crossing is supposed to make this process much less treacherous. But there is no guarantee that if you build it, they will come. Thus, kilometers of fences along the road serve to channel animals to crossing points. High concrete walls block headlights and reduce traffic noise.

“We want to mimic the habitat on both sides, with native plants and everything, so the animals don’t even see the transition,” Garvey-Darda said.

It worked. As of 2022, cameras have captured animals — including deer, elk and coyotes — using these crossings more than 5,000 times.

According to Brian White of the Washington DOT, the wildlife crossings in Banff, Alberta, Canada, were a success story to emulate. Banff’s 38 underpasses and six overpasses along a stretch of the Trans-Canada Highway through Banff National Park have reduced wildlife collisions by 80% and have been used as a model for crossings around the world.

Back in the US, there are now about 1,500 wildlife crossing structures in 43 states. In Wyoming, the pronghorn runs across Highway 191. In Florida, panthers and alligators crawl under I-75. They can be subtle; drivers may have no idea they are driving over moose in Montana or tunnels full of turtles in Utah.

But it will be hard to miss the crossing being built not far from Los Angeles; Once completed in late 2025 or early 2026, the Wallis Annenberg Wildlife Crossing will span more than 200 feet across 10 lanes of Highway 101, which could handle up to 400,000 vehicles per day. It will be the largest wildlife corridor in the country.

Beth Pratt, who serves as regional executive director of the National Wildlife Federation in California, said, “I think it’s a real miracle, that on one of the busiest highways in the world you’re driving underneath it, and a mountain lion, fox, might be walking, or a fence lizard, or a ground squirrel might have a family at the top. That’s a really promising project.

P-22 was the famous mountain lion that roamed Griffith Park in Los Angeles. When he was younger, he somehow managed to cross two highways, only to end up a lonely bachelor in Hollywood until his death in 2022.

But even for those mountain lions that do manage to find mates, the dates are a little too close together and biologists worry that the small population here could soon go extinct. The crossing, estimated to cost US$90 million, will expand the range of encounters. This is important for all types of creatures, even those that aren’t so obviously charismatic.

Back on I-90, professor Jason Irwin and his team of Central Washington University students are focusing on everything from frogs to salamanders making use of an underground passage. “It’s been really fantastic to work on a project where they value the little boy,” he said.

There are also human lives at stake. There are approximately one million collisions involving large wildlife on United States roads each year, resulting in approximately 200 human deaths.

Last year, Transportation Secretary Pete Buttigieg announced a federal grant program that awards a total of $350 million for states looking to build crossings and improve safety.

White has already seen a reduction in collisions where crossings have been built. “If you think about it that way, and think about how many accidents haven’t happened, these crossing structures pay for themselves very quickly,” he said.

And fewer road closures mean faster commutes for everyone.

Although construction of the Los Angeles intersection has meant occasional slowdowns and lane closures, Pratt said the public has been able to stay focused on the benefits in the future.

“Wildlife crossings are something, no matter if you’re Republican or Democrat, or what political affiliation — people really support them,” she said. “I think there are very few people who don’t get upset when they see a dead animal on the side of the road. So, I think this is something that in a time where we agree very little, we are practically in agreement. wildlife crossings.”

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Story produced by Michelle Kessel. Editor: José Frandino.