18.—(1) Where under an order under Article 15 vehicles may not be left at all times in a designated parking place—
(a)the parking place shall for the purposes of Articles 16, 17 and 19 be treated, as respects any time during which vehicles may not be left there in pursuance of the order, as if it were not designated by the order;
(b)any vehicle left in the parking place which remains there at the beginning of a period during which vehicles may be left there in pursuance of the order shall for the purposes of those Articles be treated as if it had been left there at the beginning of that period, but without prejudice to any rights or liabilities in respect of anything done or omitted to be done at any time before the beginning or after the end of that period.
(2) An order under Article 15 may vary or revoke—
(a)any traffic regulation order prohibiting or restricting the waiting of vehicles in any road; or
(b)any order under Article 10(4) authorising the use of any part of a road as a parking place,
and any such order as is mentioned in sub-paragraph (a) or (b) may provide that the order shall not have effect as respects any time as respects which provision is made by an order under Article 15 for the leaving of vehicles in that part of the road.
(3) A constable may suspend the use of a designated parking place for not more than seven days in order to prevent or mitigate congestion or obstruction of traffic, or danger to or from traffic, in consequence of extraordinary circumstances.