(1) The Chief Executive of the National Roads Authority may, where he or she considers it is in the interests of road safety on a national managed road, or part of a national managed road where road works are being carried out, by order apply to that road or part of it, subject to section 10C, a special limit being a speed limit of not less than 20 kilometres per hour, as the speed limit on the national managed road for mechanically propelled vehicles, in lieu of the speed limit provided or having effect under this Act in respect of the national managed road or part of it.

(2) An order under subsection (1) is in force for the duration of the road works, subject to no such order having effect for a period of more than 12 months from the date of its making.

(3) The Chief Executive of the National Roads Authority shall not make an order under subsection (1) in respect of a national managed roadwithout giving, or causing to be given, prior written notification to the county council or city council, within whose administrative area the road works occur in writing of his or her intention to make the order.

(4) Before making an order under subsection (1) the Chief Executive of the National Roads Authority shall notify the Commissioner in writing of his or her intention to make the order.