When a road or footpath or portion thereof will be altered or stopped up or interfered with under this Act, the appropriate authority may enter into and carry into effect agreements with the highway authority in reference to the construction or contribution towards the costs of such alteration or of any new road or footpath to be made under this Act and in reference to any other matters relating thereto.

The appropriate authority may by agreement delegate to the highway authority the power of constructing and maintaining all or any of such alterations or new road or footpath in which they may be interested including the structure of any bridge over or under any railway.

The purposes of this section shall be deemed to be purposes for which a highway authority may incur expenditure and borrow money.