(1)If he considers it immediately necessary for the preservation of the peace or the maintenance of order, an officer may—
(a)wholly or partly close a road;
(b)divert or otherwise interfere with a road or the use of a road;
(c)prohibit or restrict the exercise of a right of way;
(d)prohibit or restrict the use of a waterway.
(2)In this section “officer” means—
(a)a member of Her Majesty's forces on duty, or
(b)a person authorised for the purposes of this section by the Secretary of State.