NASHVILLE, Tenn (WTVF) — A proposed underground tunnel project in Nashville is facing major geological challenges—challenges even the project’s developers are acknowledging upfront.
The Boring Company, founded by Elon Musk, wants to build a 10-mile, zero-emissions tunnel system that would connect downtown Nashville with the airport and other key locations using electric vehicles.
But Steve Davis, President and CEO of the company, admits Nashville is far from ideal when it comes to tunneling.
“By the way, tough place to tunnel in Nashville,” Davis said. “If we were optimizing for easiest places to tunnel, it would not be here.”
One major obstacle: Tennessee’s bedrock.
“You have extremely hard rock,” Davis added. “Like way harder than it should be. We've done a lot of boring so I was, oh man. It's an engineering problem that's pretty straightforward to solve.”
That rock is mostly limestone—the state’s official rock—and it presents not just hardness, but unpredictability.
Dr. Kallina Dunkle, a geology professor at Austin Peay State University, said the rock formations in Middle Tennessee were heavily shaped by tectonic activity tied to the formation of the Appalachian Mountains.
“They tend to form in layers,” Dunkle explained. “They're more likely to break when they're bent, and this particular area has, you know, Appalachians forming in the geologic past. There has been a lot of bending and tilting of those layers.”
Aerial footage from Sky 5 captured images of a rock quarry showing the many layers of rock stacked on top of each other, illustrating the geological complexity.
Water adds another layer of complexity. Unlike drier climates such as Las Vegas—where The Boring Company has completed other projects—Middle Tennessee’s water table is significantly closer to the surface.
“If you're somewhere in a desert environment like Las Vegas, that might be hundreds or even thousands plus feet to get to where that water is at,” Dunkle said. “Somewhere in Tennessee like this, it might be tens of feet to maybe a hundred feet at best—most commonly less than that.”
While Dunkle isn’t ruling out the project entirely, she questions its feasibility from a geological standpoint.
“Seems like the amount of cost in engineering that would go into trying to do something like that may not really be feasible,” she said. “But I'm also not an engineer... from a geology perspective, it would really be a challenge.”
The Music City Loop, as the project is known, has drawn attention for its potential to ease congestion and revolutionize urban transit—but the rock beneath Nashville may prove to be its biggest hurdle.
This story was reported on-air and written by Kelsey Gibbs and has been converted to this platform with the assistance of AI. Our editorial team verifies all reporting on all platforms for fairness and accuracy.
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