Texas Transportation Code - TRANSP § 622.062. Time of Operation;  Lighting Requirements

(1) two red lamps visible at a distance of at least 500 feet from the rear;

(2) two red reflectors that indicate the maximum width and are visible, when light is insufficient or atmospheric conditions are unfavorable, at all distances from 100 to 600 feet from the rear when directly in front of lawful lower beams of headlamps;  and

(3) two red lamps, one on each side, that indicate the maximum overhang and are visible at a distance of at least 500 feet from the side.