(a) A vehicle shall display each lighted lamp and illuminating device required by this chapter to be on the vehicle:
(1) at nighttime; and
(2) when light is insufficient or atmospheric conditions are unfavorable so that a person or vehicle on the highway is not clearly discernible at a distance of 1,000 feet ahead.
(b) A signaling device, including a stoplamp or a turn signal lamp, shall be lighted as prescribed by this chapter.
(c) At least one lighted lamp shall be displayed on each side of the front of a motor vehicle.
(d) Not more than four of the following may be lighted at one time on the front of a motor vehicle:
(1) a headlamp required by this chapter; or
(2) a lamp, including an auxiliary lamp or spotlamp, that projects a beam with an intensity brighter than 300 candlepower.
Official text of the Texas Transportation Code as published by the Texas Legislative Council.