(1)It shall not be lawful for a person to drive a motor vehicle of any class on a road at a speed greater than the speed specified in Schedule 5 to this Act as the maximum speed in relation to a vehicle of that class.
(2)The Minister may by regulations vary, subject to such conditions as may be specified in the regulations, the provisions of the said Schedule 5.
(3)Regulations under this section may make different provision as respects the same class of vehicles in different circumstances.
(4)Without prejudice to subsection (3) above, regulations under this section may make particular provision in relation to vehicles while being driven on special roads, but such provision shall not have effect in relation to any part of a special road until such date as may be declared by a notice published by the highway authority, in manner prescribed for the publication of notices under section 1(7) of this Act, to be the date on which it is open for use as a special road.
(5)The Minister shall not have power under this section to vary the speed limit imposed by section 71 of this Act.
(6)The Minister shall not have power under this section to impose a speed limit, as respects driving on roads not being restricted roads for the purposes of the said section 71, on a vehicle which is constructed solely for the carriage of passengers and their effects, is not adapted to carry more than seven passengers exclusive of the driver, is not a heavy motor car, is not an invalid carriage, is not drawing a trailer, and is fitted with pneumatic tyres on all its wheels.