Tennessee Code Title 55. Motor and Other Vehicles § 55-8-148

(a) No person shall operate or move any crawler-type tractor, steam shovel, derrick, roller, or any equipment or structure having a normal operating speed of ten (10) or less miles per hour or a vertical body or load clearance of less than one-half inch ( 1/2 ") per foot of the distance between any two (2) adjacent axles or in any event of less than nine inches (9"), measured above the level surface of a roadway, upon or across any tracks at a railroad grade crossing without first complying with this section.

(b) Before making any such crossing, the person operating or moving the vehicle or equipment described in subsection (a) shall first stop the same not less than fifteen feet (15′) nor more than fifty feet (50′) from the nearest rail of such railroad, and while so stopped shall listen and look in both directions along the track for any approaching train and for signals indicating the approach of a train, and shall not proceed until the crossing can be made safely.

(c) No such crossing shall be made when warning is given by automatic signal or crossing gates or a flagger or otherwise of the immediate approach of a railroad train or car. If a flagger is provided by the railroad, movement over the crossing shall be made under the flagger's direction.