Road Traffic Act 1972

79 Power to impose additional requirements for vehicles over prescribed length and trailers

(1) The Secretary of State may by regulations provide that, subject to any exemptions prescribed by the regulations,—

(a) where the length of a vehicle, or the overall length of two or more vehicles of which one is drawing the other or others, inclusive of any load on the vehicle or vehicles, exceeds a length so prescribed, the vehicle or vehicles shall when on a road during the hours of darkness carry such lamps or reflectors each showing a light, or as the case may be facing, to the side as may be so prescribed;

(b) a vehicle constructed or adapted so as to be drawn by another vehicle shall when on a road during the hours of darkness carry such lamps each showing a light to the front or the side, or both, as may be prescribed;

and any such regulations may prescribe the conditions with which lamps or reflectors carried on a vehicle in pursuance of the regulations must comply and the position and manner in which they are to be attached, and may make different provision in respect of vehicles of different classes or in respect of vehicles of the same class in different circumstances.

(2) Any lamps or reflectors required to be carried by virtue of this section shall be carried in addition to, and not instead of, those required to be carried by or by virtue of the provisions of sections 68 to 78 of this Act, and accordingly any such lamps or reflectors shall for the purposes of those provisions, and in particular section 70 of this Act, be treated as not snowing a light to the front or to the rear.