May 3, 2021 |Dr. Liz Rutledge | Wildlife

How a North Carolina Coalition Is Creating Safe Passage for Wildlife in the Great Smoky Mountains

Millions of miles, lives, and dollars

In our country, millions of miles of road networks divide large, contiguous areas of habitat into smaller fragments and create both physical and noise barriers for animals. Vehicle-wildlife collisions claim the lives of more than one million animals per day on U.S. highways, and cause billions of dollars in damages and human injuries and deaths each year. It isn’t just white-tailed deer getting hit by cars. Bees, butterflies, salamanders, snakes, turtles, birds, opossums, raccoons, and even black bear and elk are all at risk. Projects across the U.S. are working to improve wildlife species’ ability to navigate this patchwork landscape through proactive transportation planning and habitat connectivity—projects like Safe Passage: The 1-40 Pigeon River Gorge Wildlife Crossing Project.

5 3 21 Coyote at Double TunnelA coyote near the edge of a road. Photo courtesy of Wildlands Network and National Parks Conservation Association.

Carving out a path for wildlife

Animals travel for many of the same reasons people do—to eat, gather resources, and to meet with others. Animals also move to fulfill life functions like finding new territory, a mate, cover, or they may travel in search of food and water or other habitat types. The amount of movement required varies by species, and those resource needs may change daily, seasonally, or over the course of years. Factors that influence whether an animal attempts to cross a roadway—and if so, when and where—may include width of a road, amount of traffic, level of noise produced by vehicles, type and density of roadside vegetation, and any physical barriers used to separate lanes.

Habitat and connectivity are the keys to helping animals navigate a fragmented landscape. Maintaining natural areas for wildlife through conservation easements or other land acquisition programs is a great first step. Large, contiguous tracts of land supporting unique habitat types, high biodiversity of flora and fauna, or threatened or endangered species should be prioritized, followed by land with high potential for habitat restoration or improvement.

Connecting these natural areas or unique habitats through systems of corridors is an effective way to reconnect land for wildlife to travel unobstructed by roads and vehicles, reducing the risk of mortality. A corridor system is essentially a network of greenways to ensure safe, on-foot wildlife movement from one location to another. When roads are involved, crossing structures can assist animals in moving from one side to the other safely.

5 3 21 bear using culvertA black bear entering a culvert under a roadway. Photo courtesy of Wildlands Network and National Parks Conservation Association.

Safe Passage: The I-40 Pigeon River Gorge Wildlife Crossing Project

Over the last few years, a diverse group of biologists, wildlife managers, transportation planners, and wildlife advocates came together to develop feasible solutions to the increasing wildlife mortality, human injury, and rising costs of damages from wildlife-vehicle collisions in western North Carolina. This group developed the Safe Passage: I-40 Pigeon River Gorge Wildlife Crossing Project.

To identify where, when, and how wildlife are crossing roads, coalition partners employed camera trap surveys, GPS tracking, and personal observation to collect animal movement data. These science-based approaches allow researchers to take a closer look at mortality “hot spots” and prioritize where crossing structures may be most beneficial. Once these crossing-structure target areas are identified, the coalition can begin working toward inclusion of wildlife-friendly passage structures to enhance the ability of wildlife to move safely over or under roads.

Wildlife crossing structures come in a variety of shapes and sizes and should be tailored to the species to ensure successful use. Elk, black bear, and white-tailed deer are the focal species of the coalition; however, improvements in habitat and connectivity will benefit small mammals, reptiles and amphibians, and aquatic species as well.

Crossing structures could consist of overpasses and underpasses, with examples including naturally occurring land bridges, man-made bridges with dry pathways or ‘benching’ or aquatic, free-flowing water, and various types of culverts. The coalition is also working with the Departments of Transportation in NC and TN to make roadways more wildlife-friendly when repairing infrastructure like on- and off-ramps and bridges.

 Proactive planning for implementing crossing structures should consider whether the structures will support terrestrial or aquatic species, or both. Use of natural materials is best, when possible, as opposed to pavement or concrete which may feel unnatural to animals, possibly preventing individuals from utilizing the crossing structures. Wildlife crossings increase in effectiveness when adjacent to proper fencing and significant protected, natural lands. While expensive, these methods have shown to be cost-effective over the long-term.

5 3 21 Elk waterville 5Elk traveling under a highway. Photo courtesy of Wildlands Network and National Parks Conservation Association.

Strong partnerships between state and federal wildlife and transportation agencies, conservation groups, policy makers, and the public can ensure that wildlife species continue to flourish through coexistence. The coalition will continue to assist with proactive planning for new construction projects to reduce wildlife mortality on roads. With approximately 80,000 miles of state-maintained highways in North Carolina combined with projected human population growth, it’s imperative we implement effective mitigation strategies in the interest of wildlife conservation and diversity.

How you can help

  • Educate yourself, friends, and family on the topic and get involved to advocate for wildlife.
  • Volunteer and support organizations making a difference for wildlife, including the Safe Passage: I-40 Pigeon River Gorge Wildlife Crossing Project.
  • Drive safely! When traveling, look for wildlife crossing signs. By simply slowing down in areas where wildlife is known to cross you can reduce the risk of a wildlife-vehicle collision.


The collaborative nature of this project has shown that we can develop solutions to challenging human-wildlife issues when partnerships are formed, and stakeholder input is valued. We look forward to the analysis of the scientific data which will inform the next steps of the coalition’s effort to provide safe passage for wildlife.

Thank you to all the dedicated Smokies Safe Passage partners:

Defenders of Wildlife

Eastern Band of Cherokee Indians

Great Smoky Mountains Association

National Parks Conservation Association

National Park Service

NC Department of Transportation

NC Wildlife Federation

NC Wildlife Resources Commission

Rocky Mountain Elk Foundation

Southern Appalachian Highlands Conservancy

The Conservation Fund

TN Department of Transportation

The Wilderness Society

Wildlands Network

Written by

Dr. Liz Rutledge

Dr. Liz Rutledge is the Director of Wildlife Resources at the North Carolina Wildlife Federation. Dr. Rutledge grew up in North Carolina and has been involved in various forms of conservation for many years. She has a BS in Biology, a MS in Natural Resources, and a PhD in Fisheries, Wildlife and Conservation Biology. Since joining NCWF in 2014, she has led a deer management program resulting in tens of thousands of pounds of venison being donated to feed the hungry and collaborated on work benefiting elk, red wolves, coyotes, alligators, white-tailed deer and other wildlife. She is a certified Wildlife Biologist through The Wildlife Society and is a member of the NC Wildlife Resources Commission Nongame Wildlife Advisory Committee, the NC Chapter of The Wildlife Society’s Conservation Affairs Committee, and the NC Hunters for the Hungry Board of Directors.