It's too early to determine the effectiveness of a wildlife-detection system along U.S. Highway 160 east of Durango, a Colorado Department of Transportation traffic engineer said Tuesday evening.
"We don't have a data pool," Mike McVaugh said. "Anecdotally, there are fewer carcasses found in the detection area than in other (adjoining) areas."
McVaugh's comments followed a Western Transportation Institute film about road ecology at the Durango Arts Center. The institute is studying the reliability of the system - installed last fall in the heart of a deer migration corridor between mile markers 95 and 96. Seventy percent of vehicle accidents in that stretch reported to the Colorado State Patrol involve deer or elk - and only half of such collisions are reported, transportation officials say.
The $1.2 million Highway 160 wildlife-detection system exemplifies the thinking of a new breed of professionals who design and build highways keeping in mind the migration patterns of wildlife whose habitat is fragmented by their projects, the institute says.
Located at Montana State University in Bozeman, the Western Transportation Institute was founded in 1994 by the Montana and California departments of transportation. Its mission is oriented toward rural transportation, particularly safety, maintenance, infrastructure, transportation planning, public transportation and freight management. Its road ecology component covers the relationship between highways and natural resources, wildlife migration near highways and vehicle-wildlife collisions.
The institute's film, "Division Street," was produced by Eric Bendick, a graduate student at Montana State University. The 56-minute film chronicles Bendick's exploration of what transportation professionals and environmentalists from Canada to the Florida Everglades are doing to facilitate the safe migration of grizzly bears, panthers, alligators, deer and turtles, which, while following ancestral migration routes, end up under the wheels of semitrailer trucks.
Bendick also talked to people who lament urban sprawl and its accompanying highways that break up wildlife migration routes. As a counterpoint, he visited a spot in the southeast corner of Yellowstone National Park that is 22 miles from a road - reportedly the furthest point from a road in the Lower 48.
The Highway 160 detection system - never tried with wildlife before it was installed in September 2008 - operates on changes in the Earth's magnetic field. A cable buried 9 inches deep, 30 feet from either side of the highway records movement, and that movement lights signs that alert motorists to the presence of animals.
Feedback from motorists has been mixed. In a story in The Durango Herald in December - two months after the system was installed - one motorist said he'd seen a doe eating grass at the foot of an unlit warning sign; another said three elk has darted in front of his truck and the warning sign hadn't been activated.
Asked whether simply reducing the speed limit would cut down on wildlife-vehicle accidents, McVaugh said it couldn't be done easily because it would involve a traffic study.
Marcel Huijser of WTI addressed wildlife mortality and the effect of barriers. He said WTI evaluates commercial animal-detection systems at an abandoned air base. Video cameras record what happens when animals trip a release. Llamas substitute for deer, goats play the role of small deer, and cattle fill in for elk.
The WTI has tested about 10 wildlife-detection systems, all of them above-ground versions except for the Highway 160 apparatus. The film and a question-and-answer session were sponsored by the La Plata County Living with Wildlife Advisory Board.