TN Code § 55-9-103 (2021)
2021 Tennessee Code|Title 55 - Motor and Other Vehicles|Chapter 9 - Equipment — Lighting Regulations|Part 1 - General Provisions|§ 55-9-103. Display of Warning Devices During Period of Disablement of Certain Vehicles

 Whenever any bus, truck, or truck tractor, except pickup trucks having not more than two (2) rear wheels and equipped with emergency flashing lights at front and rear, is disabled upon the traveled portion of the highway or the shoulder next thereto, except within a business or residential district of a municipality, the following requirements shall be complied with during the period of the disablement:   During the time when lights are required, that is, between one-half (½) hour after sunset and one-half (½) hour before sunrise and at all other times when there is not sufficient light to render clearly discernible a person two hundred feet (200') ahead, a lighted fusee shall be immediately placed on the roadway at the traffic side of the motor vehicle. As soon thereafter as possible, and in any case within the burning period of the fusee, three (3) lighted flares or pot torches shall be placed on the roadway as follows:  One (1) in the center of the line of traffic occupied by the disabled motor vehicle not less than forty (40) paces or approximately one hundred feet (100') distant therefrom in the direction of traffic approaching in that line;   One (1) not less than forty (40) paces, or approximately one hundred feet (100') from the vehicle in the opposite direction;   One (1) at the traffic side of the vehicle approximately ten feet (10') rearward or forward thereof;   If the motor vehicle is disabled within three hundred feet (300') of a curve, crest of a hill or other obstruction to view, the flare in that direction shall be so placed as to afford ample warning to other users of the highway, but in no case less than forty (40) paces, approximately one hundred feet (100') nor more than one hundred twenty (120) paces, approximately three hundred feet (300'), from the disabled vehicle;   Care should be taken in placing any flare, fusee, or any signal produced by a flame to prevent igniting any gasoline or other inflammable liquid or gas; and   As to every motor vehicle used for the transportation of inflammable liquids or inflammable compressed gas in cargo tanks, whether loaded or empty, the use of flares, pot torches, fusees or any signal produced by a flame is prohibited, and lighted red electric lanterns or red emergency reflectors shall be used in lieu thereof. Every motor vehicle, whether required to carry red electric lanterns or red emergency reflectors or not, may carry the red electric lanterns or red emergency reflectors in lieu of flares, pot torches and fusees. The placement of the red electric lanterns or red emergency reflectors in the event of disablement shall be the same as the requirements for the placing of pot torches, fusees or flares; and     During the time that lights are not required, red flags shall be placed in the manner prescribed for the lighted electric lanterns or flares, except that no flag shall be required to be placed at the side of the vehicle; however, if the disablement continues into the period when lights are required, lighted flares or lighted red electric lanterns or red emergency reflectors shall then be placed as prescribed.