(1)A constable, or a person acting under the instructions (whether general or specific) of the chief officer of police, may place on a highway, or on any structure on a highway, traffic signs of any size, colour and type prescribed or authorised under section 54 of this Act, being signs indicating prohibitions, restrictions or requirements relating to vehicular traffic, as may be necessary or expedient to prevent or mitigate congestion or obstruction of traffic, or danger to or from traffic, in consequence of extraordinary circumstances ; and the power to place signs conferred by this subsection shall include power to maintain a sign for a period of seven days or less from the time when it was placed, but no longer.
(2)Section 14 of the Road Traffic Act 1960 (drivers to comply with traffic directions) shall apply to signs placed in the exercise of the powers conferred by this section.