Wildlife Crossings Save Lives

Animal crossing structures around the world save animals including bears, bobcats, coyotes, moose, wolves, elk and elephants. The animals intuitively use them to cross, even birds and insects prefer them, because they are more comfortable not having to cross over large expanses of concrete.

Wildlife crossings like these also save money, because removing dead animals from roadways and cleaning up roadways after accidents costs taxpayer money. Saving animal lives + safer roadways saving people lives + saving taxpayer money = a more beautiful place to live with happier people and happier animals.

Los Angeles is currently designing and building the biggest animal overpass in the world in an effort to help the endangered Santa Monica mountain lion and other species to avoid the constant dangers of LA traffic.

Twenty-four wildlife crossings (highway underpasses) and 12 bridges modified for wildlife have been constructed along a 40-mile stretch of Interstate 75 in Collier and Lee counties in Florida to protect the endangered Florida panther. The underpasses on I-75 have also benefit bobcats, deer, and raccoons – and, importantly, they have significantly reduced wildlife-vehicle collisions along the interstate.

Data shows that animals are using them, which means that close calls, like hitting a deer on the highway, are far less likely to happen.

Hitting an animal is a risk anywhere roads are built through animal habitats. And as more roads are built, there are more opportunities for collisions.

According to a 2008 study commissioned by the U.S. Congress, the number of animal-vehicle collisions was increasing. Experts blamed the rise on more vehicle miles traveled combined with the growing North American deer population. But the official tally excludes accidents that have less than $1,000 in property damage. If you account for minor collisions, unreported accidents, and other variables, experts estimate that at least one million collisions with large animals – deer, elk, and moose – occur every year in the United States.

While animal-vehicle collisions rarely cost human lives, they do cost money. In the U.S., wildlife vehicle collisions cost over eight billion dollars every year. Money that is spent on vehicle repairs, medical costs, and other expenses.

Although humans tend to survive, animals are often killed. In that same report, researchers found that vehicular traffic threatened 21 endangered species.

In some places, highway planners have solved the problem by building fences to keep animals off the road. A relatively cheap solution that has been proven to reduce roadkill by over 50%. Although fences reduce roadkill, they neglect a wider problem. Besides the risk of collision, roads harm animals by dividing wildlife populations and limiting their ability to find mates, food, and other necessities of life.

In Canada, wildlife scientist Tony Clevenger has been studying how road construction affects animals in Banff National Park and how it can have important impacts on the reproductive success. Females aren’t able to access the spring habit, because they’re not crossing the highway. It’s important that we maintain these movements and we maintain this access to the biological resources throughout the year. While crossing structures do that, beginning in the 1980s authorities began installing the system of underpasses and overpasses designed for animal use only and located them where animals were likely to cross the road.

The data speaks for itself. For example, on the Trans-Canada Highway in Banff National Park there were, on average, more than 100 vehicle collisions per year before the fencing and the wildlife crossing structures. Now it’s down to less than half a dozen. These are huge reductions made by having these mitigation measures in place. They’re improving motorist safety and they’re saving lives.

In places like Banff National Park it’s important because the objective is to protect wildlife. Instead of blocking the road entirely, planners used fences to funnel wildlife towards the crossing structures, which were planted with native vegetation. A few species, like deer, elk, and moose, immediately starting using them. They were followed by more skeptical species, like wolves and grizzly bears. Within a few decades, even the most reluctant animal species, like the Lynx, had adapted to using the crossings.

In 2012, a male grizzly was recorded crossing the structures 66 times in one Summer. By crossing the highway the bears habitat expanded to include potential mates on the other side of the road, which decreases the likelihood of inbreeding. These overpasses and underpasses have restored genetic connectivity in Banff National Park

Wildlife crossing structures are fairly common in some parts of the world. Particularly in the Western European countries, like the Netherlands. But, there are relatively few in North America. The success of the Banff crossings has encouraged similar projects in the United States, like an overpass being built in Washington State.

In 2012 the Wyoming Department of Transportation built an overpass that reconnected an ancient migration route of the Pronghorn Antelope.

If these crossings are improving safety and restoring habitats, why aren’t they everywhere?

Probably the biggest factor that would limit construction of wildlife crossings is cost and having the funding within the transportation agency budgets to build these structures. The crossing structures can save money in the long term, but the initial investment is significant. Constructing an overpass like the one in Banff National Park typically costs several million dollars. Parks Canada constructed the first two overpasses at Banff in 1997 for roughly $2.5 million USD each.

To create more cost effective solutions, Clevenger organized the ARC International Wildlife Crossing Infrastructure Design Competition. ARC is an international network whose mission is to identify and promote leading-edge solutions to improve human safety, wildlife mobility and long-term landscape connectivity.