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Mountain News: Design teams working on wildlife overpasses



VAIL, Colo. - Trucks, cars, and pickups towing boats on Interstate 70 pushed up Vail Pass steadily on Saturday afternoon. Many drivers doubtlessly squinted at the roadside and wondered at the collection of people wearing hard hats.

Few could have guessed. Most fundamentally, those wearing hard hats were intent on figuring out ways to get wildlife across highways safely - and cheaply.

Teams of landscape architects and complementary disciplines from three counties and two continents had gathered at the "problem" site two miles from the summit of Vail Pass. The first roadkill after Canada lynx were reintroduced into Colorado in 1999 was squashed at the site. Cougar, moose and bears have also inadvertently testified to their use by tripping camera shutters. While I-70 is Colorado's major east-west highway, the Gore Range - which the highway traverses at Vail Pass - seems to be a major north-south route for wildlife.

Keeping hooves and hoods apart has long vexed both wildlife biologists and highway engineers. While many things have been tried, only the combination of highway overpasses and underpasses such as are found in Canada's Banff National Park have clearly worked.

Some species use the underpasses readily, but other species - especially Canada lynx, grizzly bears, and moose - seem to dislike them. For them to cross busy four-lane highways, overpasses work better.

In the West, the first overpasses were built in Banff. Some 100 to 125 collisions with elk were occurring annually during the early 1980s. Officials from Parks Canada feared eventual human fatalities as well as the more predictable death of elk.

The fear was no idle one. Wildlife biologists in the mid-1990s estimated 210 annual human fatalities in the United States from auto-animal encounters, plus 29,000 human injuries, and more than $1 billion in property damage.

The overpasses spanning the four-lane TransCanada Highway in Banff National Park certainly are impressive. Large and sturdy enough to accommodate 18-wheeled trucks, they are covered by vegetation and dirt.

But they are also very expensive. Tony Clevenger, a researcher with the Western Transportation Institute, says he believes highway engineers began sharing blueprints without rethinking the designs.

The result has been wildlife overpasses with heavy price tags, more than $12 million for the newest overpasses in Banff. As a result, there have been very few others: one each in Nevada, Utah and British Columbia, with another now under construction north of Missoula, Mont.

With that in mind, a consortium of interests sponsored the ARC: International Wildlife Crossing Infrastructure Design Competition. Announced last winter, it drew 36 applications from seven countries. From those entries were culled the five finalists: two from New York City, one from Philadelphia, with the final two from Toronto and Amsterdam.