More than 1.5 million wildlife-vehicle collisions occur each year in the Unites States. As urban development spreads through wildlife habitats, this number will continue to increase. Urban sprawl brings with it roads that crisscross through the landscape, making it challenging for wildlife to safely maneuver to their natural homes. These roads carry more vehicles, driving longer distances at often higher speeds — a trend that is likely to continue.

The National Household Travel Survey of 2001, the U.S. Department of Transportation’s most recent inventory of national personal-travel patterns, reported the following:

• The rate of increase in cars, vans and SUVs for personal travel is six times the rate of population increase.

• In 1969 72.5 million household vehicles served 197.2 million people. In 2001 203.9 million household vehicles serve 277.2 million people.

• The average vehicle miles traveled per household have grown from 12,412 miles per year in 1969, to 21,252 in 2001.

These travel scenarios, though an innate part of the American Dream, are making it increasingly difficult for highway planners to build the roads America needs while providing safe passage for wildlife.

To find solutions to this conflict, the National Cooperative Highway Research Program and Utah State University funded a three-year research project, the “Evaluation of the Use and Effectiveness of Wildlife Crossings.” John Bissonette, unit leader of the U.S. Geological Survey’s Utah Cooperative Fish and Wildlife Research Unit, assembled an international team of experts in road ecology and transportation.

Bissonette, the project’s lead researcher, was aware the team would face challenges under NCHRP’s mandate to create a Decision Guide to help practitioners incorporate wildlife crossings into the building of roads. In his research proposal for the project he wrote, “In spite of a voluminous literature on ecological road effects, there remained an obvious lack of synthesis documents to inform and help guide highway planners and engineers with environmental mitigation and enhancement.”    

It took three years of gathering research findings from hundreds of projects while asking, “what works?” and “what doesn’t?” for the team to produce the Decision Guide. The guide provides information that could save road planners both time and money as they plan, build and maintain a wildlife crossing. It is available at www.wildlifeandroads.org.

“The guidance the Decision Guide could provide is very exciting,” said Chris Slesar, environmental specialist from Vermont Transportation Agency. “I am especially encouraged by the resources page. Having the ability to find up-to-date information on what one’s peers are doing in other parts of the country in terms of habitat connectivity is very powerful.”

With just a few mouse clicks the information sharing begins, as road planners learn from others’ triumphs and mistakes. Finding the right information at the right time diminishes the costly problem of recreating the wheel.

“It is imperative that study results and practices that are both successful and unsuccessful are communicated as quickly and effectively as possible…,” Bissonette said. The most successful wildlife-transportation mitigation programs across the world have communication networks that exchange information and experience.

With the sharing of information, agencies can avoid the pricey errors of building wildlife crossings that are ineffective. These projects are too large to be second guessing about what will meet their needs. Using the Decision Guide, road planners can obtain research findings specific to their state. The guide’s “search engine” provides literature and articles about local studies, a list of where the state’s current structures exist and state agency Web sites.

The challenge now facing the creators of the Decision Guide is how to get the tool into the right hands at the right time. If the practitioners use a directive tool such as the Decision Guide early in the planning process, they’ll stand to a greater chance of having wildlife crossings in the final blueprint.

“Unfortunately too often wildlife crossing plans are brought into the process too late,” said Mac Yowell, engineering group manager for the City/County Planning Commission in Bowling Green, Ky.  Time equals money, he said, so wildlife crossings not brought into road plans in the beginning aren’t included because of the expense of having to rewrite those plans.

Now is  the time to get into to planning rooms across the nation. “Currently 50,000 bridges and roads are up for reconstruction [in the United  States],” said Patricia Cramer, research associate on the NCHRP project.

This means hundreds of road planners are at the stage where it’s easiest to add a wildlife crossing to the construction plans – and many are doing just that. In May 2007, the Utah Department of Transportation held a workshop for road planners and scientists to discuss the “most appropriate” wildlife crossings for Interstate 70. I-70 runs 232.15 miles across the central part of the state The group attending the workshop included biologists, engineers, road maintenance supervisors, rangers and federal highway administrators.

“I-70 has one of the most serious collision records with elk in the United States,” wrote William Ruediger, Wildlife Consulting Resources, (retired USDA Forest Service). “Large numbers of mule deer are also killed.” Not only are there significant safety concerns for drivers on I-70, but the wildlife collisions reduce the population of elk and deer in one of Utah’s “most popular hunting units.”

For two days, the group traveled to the hot spots along the highway discussing what type of crossings would be most appropriate. On the last day, they shared their knowledge of what does and doesn’t work. “As a result of the workshop, UDOT and its resource agency partners have developed a wildlife crossing proposal for I-70 that will reduce collisions with mule deer and elk, reduce human injuries and deaths, and provide for wildlife populations and habitat connectivity,” Ruediger said.

Workshops such as these are important because they open the communication between researchers and practitioners who have the combined knowledge to bring about the best results. They “begin the hopeful continued dialogue in a newly developing ‘culture of conservation’ within our transportation and wildlife agencies,” Cramer said.  

Dedicated sportsmen are another group actively involved in the creating crossings for wildlife.

“They have helped build new highway fencing and escape ramps, and provided valuable monitoring so the Department of Transportation could supply maintenance where it is needed,” said Bruce Bonebrake, Southern Region habitat program manager for the Utah Division of Wildlife Resources.

Their influence is felt at all levels by “providing valuable information about wildlife use areas, as well as political pressure to do highway projects, Bonebrake said.  “This aids in funding efforts through local and legislature support.”

With the help of agencies and individuals, the nation has begun reversing the past trend of creating an environment permeable for humans but not animals. Although it will take years of concentrated effort to reverse the impermeable landscape, by including wildlife passages into early road planning and sharing information — the journey has begun.

To receive more information about wildlife crossings and how to use Decision Guide for Wildlife Mitigation, visit www.wildlifeandroads.org or call Patricia Cramer, NCHRP, at (435) 797-1289.