4.—(1) The Department may by order provide for the construction as part of a road or as part of a new means of access to any land from a road—
(a)of a bridge over any navigable waters specified in the order (whether the sea, a river or other navigable waters); or
(b)of a tunnel under any such waters.
(2) An order under paragraph (1)—
(a)shall include such information as may be necessary to indicate the position and minimum dimensions of the bridge or tunnel (including, for a bridge, its minimum spans, headways and waterways and, for a tunnel, its minimum depth below the bed of the navigable waters); and
(b)shall, if it relates to the construction of a swing bridge, contain such provisions as the Department considers expedient for regulating the operation of the bridge.
(3) Before making an order under paragraph (1) the Department shall take into consideration the reasonable requirements of navigation over the waters affected by the order.