Where a highway or part thereof is altered or stopped up or interfered with under this Act, the Board may enter into and carry into effect agreements with the highway authority with respect to such alteration, stopping up or interference, or the construction of any new highway to be made under this Act, contributions to the costs thereof or any other matters relating thereto.

The Board may by agreement delegate to the highway authority the power of constructing and maintaining any such alterations or new highway, 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.