Wildlife underpass

A black bear crosses under U.S. Highway 93 through one of 41 under- and overpasses designed to separate motorists from wildlife on a dangerous stretch of roadway. While wildlife collisions are a significant threat to motorists, few transportation departments around the world consider changing designs to reduce the problem.

BRASILIA, Brazil – Rob McInerney had a safety-code rating for everything happening in a photo of a roadway – until he saw the goat.

The CEO of the International Road Assessment Program looked for speed limit signs, how the road lanes were divided, whether there were parking or sidewalk areas, the presence of pedestrian crossing facilities and how closely people appeared to be following the rules.

The answers boil down to a star ranking of that road’s safety, which guides transportation engineers on how to make things better. But the goat wandering on the asphalt didn’t fit into any of the categories.

“We don’t generally code for animals,” McInerney acknowledged. “That’s generally a land-use issue, not a matter for road construction.”

There was no workshop dedicated to animal crashes at the Second Global High-Level Conference on Road Safety that brought delegates from 116 nations to Brazil recently. Yet when asked, many quickly observed how animals were a regular hazard for their drivers.

Whether it was rural Brazilians running into herds of huge rodents called capybara, or Saudi Arabians hitting black camels while driving at night (like North American moose, a camel is just the right height to go straight into the windshield when struck), roadkill isn’t just for people.

“When you serve up a lot of land that’s ripe for sheep and cattle, it’s also ripe for kangaroos,” said Soames Job, the World Bank’s global leader for road safety. “They’re Australia’s biggest animal hazard – kangaroos and wild boars.”

But Job noted there are other aspects of wildlife on roads – which Montanans are very familiar with. Motorways can be just as bad for wildlife as wildlife is for motorists. That has led Australia to take extraordinary measures to protect its iconic koala bears, among other species.

“We have 100 species of eucalyptus trees, but koalas only eat about five of them,” Job said. “Koalas aren’t endangered, but if you have a particularly viable population, you don’t want to just split them up with a road. So we started looking at the viability of a koala community’s genetic pool if a roadway split their habitat.”

Where a road might do damage to the koala community, Australian transportation engineers are required to provide solutions. Koalas don’t like tunnels, or walking on the ground for that matter.

“They need trees that go over the road,” Job said. “On the most complicated of these mitigations, it looks like the road has been turned into a tunnel with great wide strips of trees for a bridge for the koalas.”


The challenge to those kinds of projects is fitting them into the planning debate, according to Marcel Huijser, a road ecologist with the Western Transportation Institute at Montana State University. And as with the IRAP star rating system, animals often don’t have a place on the checklist.

“In many parts of the U.S., wildlife-vehicle collisions are categorically excluded when we evaluate road sections for road safety,” Huijser said. “Older engineers are educated with the notion wildlife-vehicle collisions are random, and you can’t do anything at any specific location. But if you use human injuries and fatalities as an indicator, it's true wildlife-vehicle collisions influence where you have road safety improvement projects. On certain sections, 30 (percent) to 50 percent of all crashes relate to wildlife.”

Huijser just finished a study on the Brazilian capybara problem, and found it made economic sense to provide crossings for the rodents rather than keep hitting them.

“These are substantial animals – 120 to 140 pounds – and you can have whole herds on roads where people drive small cars with no seat belts,” Huijser said. “Whole families have died as result of crashing into capybara. We investigated to see if it was less expensive to allow them to cross than doing nothing. And the answer was yes – to do nothing is more expensive than implementing passes and fences for capybara.”

However, the things people do to make roads safer for vehicles usually make matters worse for wildlife. Erin Edge at Defenders of Wildlife said the concrete “Jersey barriers” used to divide traffic lanes are particularly troublesome.

“It’s hard enough for a cow moose to get over those, let alone its calf or deer or bear or wolf,” Edge said. “The animal tries to make a run for it, gets hung up on the Jersey rail and then it’s like being in the middle of a bowling alley.”

Traffic engineers typically attempt to find specific spots – intersections or water crossings – where specific problems can be fixed, Huijser said. But animals may regularly cross a road within a half-mile or larger stretch. That tends to blur their statistical signal. And the result is they don’t show up as the safety hazard they really are.


“About 10 years ago was very first time in Montana where folks got serious about considering the issue of wildlife road safety,” said Montana Fish, Wildlife and Parks bear manager Jamie Jonkel. “The Flathead Indian Reservation really drove that. The Montana Department of Transportation project on the Flathead is a real good example of agencies and communities working together, coming up with a real sweet highway that addresses all issues in modern-world heavy traffic.”

The 56-mile stretch of U.S. Highway 93 from Evaro Hill to Ronan has 41 wildlife crossing structures, ranging from small tunnels for turtles to the “Animal’s Bridge” overpass. The structures have been credited with an at least 40 percent annual reduction in animal collisions in the area.

Other areas aren’t so adaptive. Jonkel said he has picked up 14 road-killed black bears in one short stretch between Clinton and Bonner this fall. His colleagues in FWP Region 1 have collected three grizzly bear carcasses – a federally threatened species – from the sides of Montana Highway 83.

But the Highway 93 project probably wouldn’t have happened if the Confederated Salish and Kootenai Tribes hadn’t insisted the Montana Department of Transportation consider wildlife in its highway reconstruction plans.

In Brasilia, road safety advocates bemoaned how difficult it is to focus on a problem where traffic engineers, law enforcement officers and hospital doctors rarely compare notes. Road ecologists such as Huijser struggle to be heard in the clamor for more and faster motorways.

“As more and more folks move to the West and populations increase, a big item is making highways even better,” Jonkel said. “But that’s only going to get harder and tougher for wildlife. That’s why it was great when we had other governments like the tribes, that can demand certain actions that may not fit standard practices in a department of transportation. They can say if you are to do something with a road on our reservation, we want you to implement mitigations. We care about wildlife. It’s a value we have as a people, and we will not allow you to take action unless you include mitigations that allow for wildlife.”

“A similar thing happened on Interstate 90 at Snoqualmie Pass, but there it was the U.S. Forest Service that said you can’t upgrade the road without mitigations for wildlife,” Jonkel added. “It takes a variety of pressures to make sure that mitigations are included.”

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