Both tunnels, however, are longer than the Backbone Rock Tunnel near Shady Valley, Tennessee, which at around 20 feet (6.1 m) long, is the world's shortest railroad tunnel.

The title of the world's shortest train tunnel is often attributed to the Bee Rock Tunnel near Appalachia, Virginia, on the former Louisville and Nashville Railroad line. This "Lilliputian" tunnel measures only 47 feet (14.3 meters) in length. It was carved through a limestone "spine" in the late 19th century and is so short that a single modern locomotive would be longer than the tunnel itself. While it is no longer in active use for heavy freight, it remains a popular landmark for hikers and rail enthusiasts. Another contender for the "shortest in active use" is the West-Hafner-Tunnel in Austria, which is roughly 12 meters long. These tunnels are often called "accidental" tunnels, created when engineers decided to punch through a small rock outcrop rather than go around it or blast it away entirely. In 2026, many of these historic shortest tunnels are being preserved as part of "Rails-to-Trails" projects, allowing pedestrians to walk through a piece of engineering history that takes only a few seconds to traverse.