17.—(1) Subject to the following provisions of this Part and, in particular, to such directions and guidelines as may be given by the Minister under section 41, it shall be the general duty of the Authority to secure the provision of a safe and efficient network of national roads and for that purpose it shall have—

(a) overall responsibility for the planning and supervision of works for the construction and maintenance of national roads, and

(b) such other functions in relation to the construction or maintenance of national roads as are assigned to it by or under this Act.

(2) In the performance of its functions under subsection (1), the Authority shall consider the needs of all road users.

(3) The Minister may, by regulations, assign to the Authority such additional functions in relation to the construction or maintenance of national roads as from time to time he considers appropriate.

(4) The Minister may make regulations providing that any function relating to national roads conferred on him or on a road authority under any enactment (including this Act), or on the Commissioner under the Road Traffic Acts, 1961 to 1987, shall, where the Minister is satisfied that the function could be more effectively performed by the Authority, in lieu of being performed by him or by that authority or by the Commissioner, be performed by the Authority with effect from a date specified in the regulations.

(5) Whenever regulations under subsection (4) are in force in relation to a particular function, a reference in any enactment concerned to the Minister, to the road authority concerned or to the Commissioner shall be construed as including a reference to the Authority and the function to which the regulations relate shall be a function of the Authority.

(6) Regulations under subsection (3) or (4) may contain such incidental, supplementary, consequential and transitional provisions as appear to the Minister to be necessary for the purpose or in consequence of, or to give full effect to, the regulations.