(1)Subject to and in conformity with such general directions as may be given by the Minister and the Secretary of State acting jointly, or such other directions as may be given by the appropriate Minister, a highway authority may cause or permit traffic signs to be placed on or near any road in their area.
(2)The appropriate Minister may give directions to a highway authority—
(a)for the placing of a traffic sign of any prescribed type or authorised character specified in the directions;
(b)for replacing a sign so specified by, or converting it into, a sign of another prescribed type or authorised character so specified.