The authority is hereby authorized to use the rights-of-way of all public roads in the state without securing the prior approval of the state or of its agencies or departments or the governing body of any county and subject only to the necessity of obtaining the municipal consent required by Section 220 of the Constitution of Alabama; provided, however, that nothing herein shall be construed to exempt the authority from the requirements of Section 23-1-4; and provided further, that the authority shall have the duty to restore at its expense all roads, highways and public rights-of-way in which it may have made excavations or done other work in laying pipes or performing any of its other corporate functions.