15.—(1) Where the Department considers it expedient that—
(a)any existing road;
(b)any road in the course of construction; or
(c)any road proposed to be constructed,
should be designated as a special road, the Department may make an order (a “designation order”) designating that road or proposed road as a special road.
(2) The Department shall not make a designation order in respect of an existing road unless it is satisfied that adequate alternative facilities for traffic, other than traffic authorised to use the road on its being opened for use as a special road, are available or will be made available before the date on which the road is opened for use as a special road.
(3) Without prejudice to any other provision of this Part, a designation order may authorise the Department to construct a new road where it appears to the Department to be necessary or desirable for any purpose connected with a special road and, where any such new road is constructed for temporary purposes, to close that road after such period as may be specified in or determined under the order.