Tennessee Code Title 65. Public Utilities and Carriers § 65-11-112

(1) The railroad company owning or operating the track at any such crossing shall maintain in good and safe repair at its sole expense all that part of any underpass or overpass and the approaches thereto on its rights-of-way, and also that part of any overpass structure or the approach thereto not supported by a fill, whether on its right-of-way or not, except the surface of the highway; provided, that the flooring of any overpass which supports the surface of the highway or which may constitute the surface of the highway shall be considered as a part of the structure to be maintained by and at the expense of the railroad company; and

(2) The commissioner of transportation or the commissioner's designee shall maintain in good and safe repair out of the public funds, any fill, approach to any such crossing not on the right-of-way of the railroad company, and also the entire surface of the highway at all points.