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for people who care about the West

Safe crossing

Armed with new research, traffic engineers are finding ways to stop highway carnage


The 600-pound elk hesitates in the dark meadow, pausing in the doorway of the small mesh enclosure, tantalized by the smell of a pile of alfalfa. Not far away, Arizona Game and Fish wildlife biologist Jeffrey Gagnon sits in a trailer and watches the elk through a night-vision camera, his finger poised above the switch that will drop the door on the cage should the elk take the bait. 

The elk and Gagnon will both be up all night, playing their small but crucial role in curtailing a lopsided, messy war that kills some 200 humans and more than 1.5 million elk and deer each year. With each crash costing an estimated $2,300 in property damage, these wildlife encounters cause $10 billion in damages annually. Moreover, cars kill perhaps 1 million other vertebrates every day while creating barriers that fragment habitat and threaten some species with extinction, including high-profile ones like the Florida panther. 

This explains the importance of Gagnon and the elk he's about to trap, wrestle to the ground, radio-collar and then track for the next two years. He's one of the lead researchers in an attempt to build a network of wildlife-friendly underpasses beneath the newly widened State Route 260, which runs along the base of Arizona's Mogollon Rim. Stung by lawsuits and the deaths of up to five drivers annually, the Arizona Department of Transportation called in wildlife biologists to determine whether wildlife crossings could make a difference. Five years later, a combination of underpasses and fencing has reduced collisions by a heartening 83 percent. As a result, this 18-mile stretch of busy highway has provided a national model, as both the federal government and key states work to protect wildlife and drivers by retrofitting highways and considering wildlife issues at the drawing-board stage. 

"I'm so proud of Arizona," says University of Utah researcher Patricia Cramer, a passionate advocate for wildlife-friendly highway design. Spurred by 12,000 crashes a year involving deer in Utah, Cramer and fellow University of Utah researcher John Bissonette recently compiled a list of 400 road crossings built to protect wildlife. 

At this point, Arizona's high-tech set of crossings on Highway 260 is the best-studied system in the country, perhaps reflecting the impact of a multimillion-dollar jury verdict that caught the attention of highway designers nationwide. 

In December 1998, the car Jerry Booth was driving along I-40 near Flagstaff crashed into the carcass of an elk that had been hit by another motorist and left on the highway. Booth, who suffered serious injuries in the crash, sued the state for not keeping the roadway clear. A jury in 2004 awarded him some $3 million, agreeing that the state should have gotten the dead elk off the highway faster. When an appeals court upheld the verdict, it sent a chill through state highway departments nationwide, and gave an extra boost to research into ways to reduce wildlife-related car crashes. 

Meanwhile, state and federal governments grapple with an aging and deteriorating interstate highway system. One recent survey revealed the need to replace 59,000 bridges along interstate highways in the next decade. Each of these could become an effective wildlife crossing - if planners think ahead. 

"The number-one priority is to consider wildlife and ecosystems in the transportation-planning process - at the very beginning of that 15- to 20-year pipeline," says Cramer. "Now, wildlife isn't considered until it's too late to change anything." 

When it came time to widen Arizona's Highway 260, however, transportation planners turned to Game and Fish researchers Norris Dodd, Gagnon and others. The biologists have spent the past five years capturing, radio-collaring and monitoring more than 100 elk to study how the animals react to a combination of fences and wildlife-friendly underpasses. In areas where no streams or gullies offer the opportunity to construct an underpass, the biologists and traffic engineers have installed military-grade motion detectors that trigger warning lights on the highway when a large animal approaches the road. 

The satellite-connected radio collars record an elk's position every two hours for two years, allowing the biologists to accumulate a treasure trove of information about elk behavior. The collars, along with cameras that watch the underpasses, enabled the researchers to study how elk reacted to the highway and to different underpass designs. This detailed tracking revealed that elk won't detour very far to use an underpass, a fact that makes both fencing and the spacing of the underpasses crucial. It also revealed a simple answer to the question, "Why did the elk cross the road?" It crossed to get to the meadow on the other side, where the grass provides the most energy per mouthful to animals that must feed constantly. Thus, the most popular elk crossings are near meadows. 

Moreover, the radio collars showed that a small percentage of the elk cross repeatedly - and they're the ones most likely to end up getting smacked by a car. Although most elk won't go far out of their way to use an undercrossing, once funneled by fencing to one, they cross readily. The year-round elk act as pioneers and may speed the acceptance of the underpasses by other elk migrating through the area. The elk much prefer underpasses with an open design lacking high concrete walls, presumably because the dark ledges at the top of the wall look like a great place for mountain lions to lurk.

Once the tracking data pinpointed areas with high crossing rates that weren't close to any underpasses, the biologists added motion sensors linked to warning lights to cover those stretches. Measures of traffic speed demonstrated that stationary wildlife warning signs had virtually no impact on drivers. 

The crossings have proven so successful that Arizona now plans to install a similar network along Interstate 17 near Flagstaff. In addition, the state is working on crossings to protect a herd of bighorn sheep near Hoover Dam that frequently crosses Highway 92. 

The combination of new research, worrisome lawsuits and pressure from conservation groups has dramatically increased interest in wildlife crossings among traffic engineers. It's one of the rare environmental gains in recent years. 

"I've been working on this issue for seven years, and on every other issue conservationists have been getting hammered. But on this issue, there's actually been some progress," says Tricia White, director of the Habitat and Highways campaign for Defenders of Wildlife and author of Getting Up To Speed, an activist's guide to the topic. 

Specifically, conservationists won a provision in the 2005 highway bill that requires transportation planners to consult with environmental groups, land-use and wildlife agencies early in the planning process. Previously, pork-barrel politics forced dramatic changes in the original plans and engineers rarely even considered things like wildlife until well after budgets and alignments had already been set, says White. 

Cramer cites a list of projects that prove that careful, early planning not only saves lives; it can avert enough crashes to recover the cost of a project in 10 to 15 years. Although major wildlife crossings can cost millions to retrofit or design, those costs amount to small change on a multibillion-dollar highway, notes Cramer. 

She cites other model projects, including a network of 80 crossings in Florida to protect the endangered Florida panther and Florida black bear, a network of 52 wildlife crossings on Highway 93 in Montana, the Tijeras Canyon project in New Mexico outside of Albuquer-que, 17 crossings on Highway 90 in Washington state, the study of crossings as part of the Southern Rockies Ecosystem Project in Colorado, and landscaped overpasses in Banff National Park in Canada that allow notoriously road-shy grizzly bears to cross a major highway safely. 

Many of those projects have studied Arizona's careful redesign of Highway 260, in part because years of data from the radio-collared elk have provided remarkable insight into the reaction of animals to a busy highway. That underscored the complexity of animal behavior and the need to build that knowledge into the design of freeways, rather than relying on expensive stopgap measures once a highway has fragmented habitats, experienced accidents, and garnered a political constituency. 

The plight of the Florida panther provides one obvious example, notes Cramer. The population of panthers had declined to less than 100 in the 1980s, with rampant development restricting their habitat. After cars killed 16 panthers in a single year, the state built a network of 24 underpasses, dramatically reducing the roadway deaths and helping the nearly extinguished population begin to expand. Florida kept pace with additional underpasses, for both the panthers and for the endangered Florida black bear. The state now boasts 80 specially designed underpasses, making it the number-one state for wildlife crossings. However, continued development and new roads have so fragmented the habitat of the wide-ranging bears and panthers that they're now routinely killing one another in a grim struggle for territory, says Cramer. 

"The number-one solution is to consider wildlife early," says Cramer. "But sometimes that's going to mean maybe you don't build that road." 

Advocates note that careful planning for wildlife makes both environmental and economic sense. For instance, Vermont recently decided to stop putting bridge pilings in the middle of streams. When combined with a design that leaves a shoreline on each side of the stream to allow the passage of animals that don't like to swim, such a redesigned bridge provides a crossing point for a wide array of species. Moreover, Vermont soon discovered that a redesign intended to help fish and animals also saved money, by reducing the maintenance cost associated with the stream-scoured pillars planted in the water. 

Ultimately, planners must sometimes consider whether another highway is even needed, says White, no matter how politically appealing the pork-barrel payoff. 

"A lot of people see roads as inevitable, a necessary evil," says White. But the full impacts of major roads have become increasingly clear, right down to the documented effects on the soil far beyond the edge of the road itself. "So how many more roads are we going to build? The learning curve is very steep at this point; we're just starting to understand the impacts. So let's put the brakes on." 


A Phoenix based-freelance writer and former editor of Arizona Highways magazine, the author has covered environmental issues in the West for 20 years and written 12 books.