The costs of getting around keep rising—and we’re not just talking about gas. Take the materials required to build highway overpasses: Costs for cast-in-place concrete and steel have tripled in the past 12 years. As a result, wildlife crossings are viewed as luxury items, says Tony Clevenger, a wildlife ecologist with the Western Transportation Institute (WTI) at Montana State University. As Landscape Architecture (March 2011) reports, though, when animals can’t cross the road to reach their natural habitats, we all end up paying.
According to the Insurance Information Institute, deer collisions with vehicles account for 1.6 million crashes, about 200 human deaths, and more than $4.6 billion in medical costs and car repairs every year. Millions of other animals are also killed by drivers, and that’s taking a toll on species populations.
When Clevenger studied Canada’s Banff National Park, he found that its 22 underpasses and two overpasses that serve as wildlife crossings have reduced animal fatalities by 80 percent. Data like this prompted WTI and the Woodcock Foundation of New York City to sponsor the first ARC International Wildlife Crossing Infrastructure Design Competition in 2009. The organizers, who wanted to raise the profile of wildlife crossings, also hoped to encourage design that’s both affordable and ecologically minded.
Currently, most crossings feature a “green toupee” of soil and plants slapped on top of concrete, points out ecologist and planner Nina-Marie Lister, who served as a contest consultant. “Now we want to show what the possibilities are,” she says.
Engineering firm HNTB and landscape architects Michael Van Valkenburgh Associates with Applied Ecological Services won the first contest for their design of a crossing near Vail, Colorado, that will feature a wildlife overpass, understory planting, selective thinning of the tree canopy, controlled burns, fencing, and adaptable precast concrete modules, which lower future design costs. The design also aims to extend habitat corridors and encourage wildlife movement.
And that, says the deer that just dodged a pair of headlights, is priceless.