A range of solutions, some expensive, are recommended to reduce wildlife-vehicle collisions near Great Smoky Mountains National Park/NPS file

A lengthy analysis of wildlife movements around Interstate 40 near Great Smoky Mountains National Park has pointed to sections where wildlife-vehicle collisions are a common occurrence and suggests solutions to reduce those deadly incidents.

Conducted by the Wildlands Network and the National Parks Conservation Association, the study's resulting 86-page report looks at 28 winding miles of Interstate 40 in Tennessee and North Carolina through the Pigeon River Gorge that is a hot spot for wildlife-vehicle collisions.

“When this highway was first built decades ago, wildlife wasn’t being considered,” said Dr. Liz Hillard, senior wildlife biologist for the Appalachian Region at Wildlands Network, and lead author of the report that was issued late last month. “We now know how detrimental roads are to wildlife, and have a tremendous opportunity to use our research to influence positive conservation outcomes on the ground by connecting wildlife habitat.”

The study identifies priority areas along I-40 where mitigation strategies, such as road crossing structures, could be best implemented to reduce wildlife-vehicle collisions and increase wildlife habitat connectivity. In order to do so, the research team amassed data on patterns and processes of elk, bear, and white-tailed deer’s interactions with the road using a variety of methods including:

• Analyzing roadkill data
• Monitoring wildlife activity with motion-activated trail cameras along the roadside and in existing culverts, tunnels and bridges
• Tracking elk using GPS-collars

In the mountainous region at the border of Tennessee and North Carolina, Interstate 40 winds through the steep and rocky Pigeon River Gorge (PRG, Gorge). The busy highway divides the Pisgah and Cherokee National Forests (512,758 and 650,000 acres, respectively) and is in close proximity to the 522,42-acre Great Smoky Mountains National Park (GSMNP). These protected areas exist in an ecologically diverse and important region and are home to a growing and dispersing elk population, a large and robust black bear (hereafter, bear) population, and modest numbers of white-tailed deer (hereafter, deer). Due to the abundance of large-bodied wildlife and increased traffic in the region, [wildlife-vehicle collisions] are frequent. -- Wildlife Corridors report.

"Wildlife-vehicle collisions are not inevitable. Roads and cars can coexist with the beautiful wildlife that wander in and around Great Smoky Mountains National Park for food, mates, and more. Our research findings reveal where and how the North Carolina and Tennessee Departments of Transportation can act to both improve public safety and wildlife's ability to safely cross this highway," said Jeff Hunter, senior program manager for the National Parks Conservation Association. “We know that experts at these two transportation agencies are deeply committed to working to solve this problem. Together, we know we can.”

The solutions are not inexpensive, as the Wildlife Corridors report calls for projects ranging from directional fencing to funnel wildlife to desired crossings and larger culverts to overpasses for wildlife to avoid highway crossings. There also are calls for purchasing land or seeking conservation easements to provide additional habitat for species.

The entire report can be found here.

The two groups say the Pigeon River Gorge is ecologically significant, not only because of the diversity of wildlife that live there, but also due to its strategic location in the Southern Appalachian mountains, a key corridor for species movement, particularly as habitats shift due to human development and climate change. In addition to large mammals like black bears, deer and elk, the area’s vast array of species includes many smaller animals like bobcats, red foxes, Northern river otters, timber rattlesnakes and Eastern box turtles.

Wildlife crossings are a proven solution to reducing wildlife-vehicle collisions (in some cases by more than 90 percent) and promoting connectivity among wildlife habitats, the groups added. The report’s findings will provide the North Carolina and Tennessee departments of transportation with the data they need to incorporate wildlife mitigation strategies into future transportation plans.

Traveler postscript: NPCA's Jeffrey Hunter discussed the need for wildlife overpasses with the Traveler's Lynn Riddick in this podcast from March 2021.