Crossing structures can reduce crashes by as much as 80 percent in some areas of the country
BY NATHAN DENZIN, The Badger Project
Deer cause more than 16,000 car crashes in Wisconsin every year, leading to millions of dollars in damage, and even a few lives lost. Yet the state has no wildlife crossing structures big enough for deer, which are effective in other states. The Wisconsin Department of Natural Resources says they’re not feasible.
Vehicles collide with deer somewhere in Wisconsin an average of about 45 times a day, according to records from the DNR. An average deer crash costs about $4,800, according to American Family Insurance. That puts the estimated total bill for deer crashes in Wisconsin at more than $75 million per year.
On top of the monetary damage, deer crashes kill an average of about eight people in Wisconsin every year, according to the Wisconsin Department of Transportation.
Some states around the country, such as Utah, Nevada and California, have embraced wildlife crossing structures to help reduce the problem. These are tunnels or bridges designed to move wildlife safely through roadways. Crossing structures can reduce crashes by as much as 80-90 percent in some areas, according to the Center for Large Landscape Conservation, a Montana group with a goal to unite American landscapes.
“The fact is that wildlife-vehicle collisions are expensive a lot of times, especially with these medium-to-larger size animals,” said Daniel Olson, Wildlife Migration Initiative Coordinator at the Utah Division of Wildlife Resources. “It doesn’t take avoiding very many crashes for [crossing structures] to pay for themselves, because the damage and injuries are so high for those types of events.”
Just as in Wisconsin, Utah’s deer population causes the majority of wildlife crashes. But the dominant species in Utah are mule deer, a migratory species. They account for about 10,000 crashes a year, according to Olson.
Utah has been constructing wildlife crossing structures since the 1970s, but the state has recently moved to build more. There are currently more than 50 in the state.
Fencing has to be installed along roadways for miles in either direction to ensure wildlife is properly funneled through the structure. Without it, animals would just shift the collision problem down the road, Olson said.
“We typically see a huge reduction in vehicle collisions when we use wildlife crossing structures, plus exclusionary fencing for the animals to cross,” Olson said. “Those are a really effective combo.”
In Wisconsin, the DOT has installed many wildlife crossings throughout the state for smaller animals like turtles, and deer are able to use the wildlife shelves or walkways built under waterway bridges, said Kristin McHugh, a spokesperson for the DOT.
But the DNR has decided larger wildlife crossings wouldn’t be effective in “significantly” reducing deer collisions, said Scott Roepke, a Wisconsin DNR Area Wildlife Supervisor in La Crosse.
Unlike mule deer out west, white-tailed deer in Wisconsin are not very migratory. So building costly crossing structures in the state would have minimal impact, Ropeke said. While Utah is able to track migration patterns and create models to predict where mule deer will cross, Wisconsin doesn’t necessarily have that opportunity.
The Wisconsin DOT does use fencing to try and funnel deer under bridges and away from high-traffic areas, according to the agency’s public affairs office.
Roepke’s district office in La Crosse is considering installing an elk crossing near Black River Falls and has submitted a project plan to their superiors, but no decisions have been made.
Also, the recently-passed federal infrastructure bill allocates $350 million to states specifically for the construction of wildlife crossings.
Success out west
While the impact of wildlife crossings for drivers can be beneficial, the structures can also help restore the historic migration patterns of local wildlife in some places.
When animals eventually figure out how to use a crossing structure, they use it a lot. A 2013 study in Utah showed that mule deer used crossing structures in the state a total of 31,000 times over five years.
“What that tells me is animals that were restricted now have access to a vastly bigger slice of habitat because we put that crossing in,” said Matt Howard, Natural Resource Manager at the Utah Department of Transportation. “It will help build healthier herds and populations going into the future.”
Despite seeing local reductions in wildlife-vehicle crashes around crossing structures, Utah hasn’t seen much change in crash trends throughout the state.
“Because [Utah] is growing so fast, the problem areas just shift — once we solve a problem in one area, a new one will pop up,” Olson said.
The number of crashes in Utah compared to 10 years ago has stayed relatively stable despite a fast-growing population because of the mitigation efforts, Olson added. On top of that, these structures can take years to plan and millions of dollars to construct — an average culvert or bridge takes five years to plan and as much as $7 million to build, Howard said.
“If you want to see a crossing structure up five or ten years from now, the work starts today,” he said.
The Badger Project is a nonpartisan, citizen-supported journalism nonprofit in Wisconsin.
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