Tennessee Standard Track is a system of railroad tracks that are built and maintained by the state of Tennessee. It consists of more than 1,000 miles of track and is used by freight and passenger trains. The track is divided into two categories; mainlines and branch lines. Mainlines are the larger, more heavily trafficked routes running through the state, while branch lines are the smaller, less traveled routes which connect towns and cities throughout the state. Tennessee Standard Track is maintained by the Tennessee Department of Transportation, which periodically inspects and repairs the track to ensure its safety. The track is also subject to regular maintenance and upgrades to keep up with changing industry standards.