15.—(1) Where a National Park authority has made an order relating to any road, the authority must take such steps as are necessary to secure—
(a)before the order comes into force, the placing on or near the road of such traffic signs in such positions as the National Park authority may consider necessary for securing that adequate information as to the effect of the order is made available to persons using the road;
(b)the maintenance of such signs for so long as the order remains in force; and
(c)in a case where the order revokes or amends another traffic regulation order, the removal or replacement of such existing traffic signs as the authority considers requisite in consequence of that revocation or amendment.
(2) The National Park authority must consult the appropriate Crown authority before carrying out the requirements of sub-paragraphs (a) and (c) of paragraph (1) in relation to a Crown road.