Section 5. The department may, in order to provide for unusual, sudden or unforeseen transportation needs, or to avoid interruption of existing transportation facilities, issue such temporary licenses as it deems that public convenience and necessity may require over such route or routes as it shall specify. An applicant for such temporary license shall serve a copy of the application on all affected cities and towns. Applications filed with the department shall be accompanied by a certification that such service has been completed. All temporary licenses issued under the provisions of this section shall be limited to such period as the department shall specify, not exceeding one hundred and twenty days. No such license shall be renewed, nor shall more than one such license for substantially the same route be granted to the same person because of the same emergency.