Certain vehicles must stop at all railroad grade crossings

(a) The driver of any motor vehicle carrying passengers for hire, or of any school bus whether or not the school bus is carrying any school child, or of any vehicle carrying explosive substances or flammable liquids as a cargo or part of a cargo, before crossing at grade any track or tracks of a railroad, shall stop the vehicle within fifty feet (50′) but not less than fifteen feet (15′) from the nearest rail of the 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, except as provided in this section, and shall not proceed until the driver can do so safely. After stopping as required in this section and upon proceeding when it is safe to do so, the driver of any such vehicle shall cross only in such gear of the vehicle that there will be no necessity for changing gears while traversing the crossing and the driver shall not shift gears while crossing the track or tracks. (A) For purposes of a conventionally operated vehicle, every person who drives or is in actual physical control of a vehicle. See Tennessee Code 55-8-101Police officer: means every officer authorized to direct or regulate traffic or to make arrests for violations of traffic regulations. See Tennessee Code 55-8-101Railroad: means a carrier of persons or property upon cars, other than streetcars, operated upon stationary rails. See Tennessee Code 55-8-101School bus: means every motor vehicle owned by a public or governmental agency and operated for the transportation of children to or from school or privately owned and operated for compensation for the transportation of children to or from school. See Tennessee Code 55-8-101Traffic: means pedestrians, ridden or herded animals, vehicles, streetcars and other conveyances either singly or together while using any highway for purposes of travel. See Tennessee Code 55-8-101Traffic-control signal: means any device, whether manually, electrically or mechanically operated, by which traffic is alternately directed to stop and to proceed. See Tennessee Code 55-8-101Vehicle: means every device in, upon or by which any person or property is or may be transported or drawn upon a highway, excepting devices used exclusively upon stationary rails or tracks. See Tennessee Code 55-8-101(b) No stop need be made at any crossing where a police officer or a traffic-control signal directs traffic to proceed. (c) A violation of subsection (a) is a Class B misdemeanor.