The DPS notes that Texas Transportation Code Chapter 547 contains detailed requirements for trailer brake lights. Unless specifically exempted, Section 547.323 of the code requires two stop lamps for every "trailer, semitrailer, or pole trailer." Each stop lamp must emit a red or amber light "visible in normal sunlight at a distance of at least 300 feet" and that displays when the vehicle service brake is used. The stop lamp can be part of another rear-mounted lamp.
The exceptions to the code, by which certain Texas boat trailers do not need brake lights, applies to trailers of a certain weight operated at certain times. Boat trailers with a gross weight of 3,000 pounds or less not operated at night or when light or weather make a vehicle on a highway "not clearly discernible at a distance of 1,000 feet ahead" are exempt from electric light requirements under transportation code 547.304.
Texas farm and fertilizer trailers enjoy the same exemption as boat trailers weighing less than 3,000 gross pounds. For a no-brake-lights exception, the farm or fertilizer trailer has to be operated during daylight hours when visibility is at least 1,000 feet. These trailers can weigh between 4,000 and 34,000 pounds when loaded. These rural trailers are exempt from brake light requirements when transporting seasonal agricultural products or livestock from the farm or ranch to processing, market, or storage, when moving farm supplies "from the place of loading to the farm," and when doing a few other short term hauling duties.
