KNOXVILLE, Tenn. (WATE) — A report released this summer is shedding more light on the effects of driver activity along Interstate 40 on wildlife in the Smokies near the Tennessee-North Carolina border. The report draws information from a study that was conducted by a team of researchers and scientists over a three-year period.

The study – one of the largest road ecology research projects ever completed in the eastern United States – is meant to offer a framework that identifies areas along the corridor where wildlife crossing structures could best be implemented. The goal is to reduce wildlife-vehicle collisions or WVCs and increase wildlife habitat connectivity in the area.

The I-40 Pigeon River Gorge Wildlife Crossing Project, which is spearheaded by the Safe Passage Coalition, is still in the works. New research from the study conducted on a 28-mile section of I-40 between Asheville, N.C. and Knoxville, Tenn. aims to improve wildlife connectivity and human safety along the corridor. The study specifically looks into how larger wildlife such as the bear, white-tailed deer and elk populations are affected in WVCs.

“Roads are now recognized as one of the most important and most lethal barriers to wildlife movement around the world,” the report introduction states. “In the mountainous region at the border of Tennessee and North Carolina, Interstate 40 winds through the steep and rocky Pigeon River Gorge. These protected areas (part of the Great Smoky Mountains National Park) are home to a growing and dispersing elk population, a large and robust black bear population, numerous white-tailed deer, and diverse species of mammals, reptiles, amphibians, birds, and other taxa.”

Experts argue these wild animals are in need of safer areas to cross the interstate that runs through the Smokies, and the report aims to highlight the locations where animals cross the most, which species are the most active, what parts of the roadway are permeable and determine where elk approach and cross the roadway. Much of the wildlife activity data was collected with the use of motion-detection cameras, GPS elk-collar tracking and traffic data regarding WVCs.

Wildlife-Vehicle Crashes

The WVCs data was focused on bear, deer and elk road mortalities from both Tennessee and North Carolina transportation departments; including carcass removals and law enforcement crash reports between 2001-2020. Using a formula, the researchers were able to calculate “hot spots” of WVCs and also evaluated road and landscape features.

The results have moved the Safe Passage Coalition to recommend 20 detailed mitigation recommendations for improvements to existing structures or the creation of new structures throughout the Pigeon River Gorge.

The research team recorded 336 incidents of WVCs in the Pigeon River Gorge from 2001-2021, with 304 of those incidents meeting the criteria for further evaluation. WVC counts were highest in October, November, and December. Of those incidents, there were 167 bears killed; 51 either bear or deer killed (they could not distinguish which); 85 deer were killed and 1 elk was killed in that timeframe. The number of incidents ramped up in 2018.

“Not surprisingly, the highest yearly WVC counts occurred during years 2018-2020, when roadkill surveys from our research and state agencies records were included in yearly totals,” the report states.

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Where to build the wildlife crossings?

Based on the research findings, the study also gives top-priority locations in both states where bridges and underpasses can be replaced so wildlife can cross I-40 in the Pigeon River Gorge safely – which also keeps humans safe from WVCs.

In Tennessee, three locations were listed as the highest priority recommendations for construction:

  • Waterville Bridge: Add a wildlife-friendly shoulder along the underpass road when the bridge is replaced, and consider a future wildlife and pedestrian overpass in the area.
  • Naillon Branch: Replace the existing culvert with a larger structure suitable for all target species or construct an elk-friendly overpass. Pursue land acquisition or conservation easements to stabilize the area for wildlife.
  • Laurel Hollow: Replace the existing culvert with a larger structure (culvert or small bridge) suitable for all target species.

In North Carolina, four locations were listed as the highest priority recommendations for construction:

  • Wilkins Creek Overpass: Construct an overpass over I-40 between Wilkins Creek Box Culvert A (i.e. north) and the NCDOT Rest Area. Pursue land acquisition or conservation easements to stabilize the area for wildlife.
  • Single Tunnel Overpass: Construct an overpass extending the existing Single Tunnel land bridge across the rest of I-40.
  • Cold Springs Creek Exit Culverts: Replace the existing culverts on both the entrance and exit ramps with larger structures to facilitate better terrestrial and aquatic wildlife passage.
  • Groundhog Creek: Replace the three small existing culverts with a larger structure suitable for all target species.

Details, supportive data, and additional steps recommended for each site are expanded upon within the report. Other sites for wildlife crossing areas in the Pigeon River Gorge are also shared. The report introduction and link to the full report can be viewed here.

Additional information on the Safe Passage Coalition and the work they’re continuing for the I-40 Pigeon River Gorge Wildlife Crossing Project can be found here.