Traffic continues to be a concern in the growing area of Middle Tennessee, but more specifically in Rutherford County. To better handle traffic congestion, the idea of building a commuter rail line between Murfreesboro and Nashville has been suggested multiple times over the past few years. Rutherford County Mayor Joe Carr said… Carr said that Governor Bill Lee has shown interest in building Smart Lanes on the interstate, which would be paid for by a mixture of public and private dollars& .