(1) Before entering into a lease-purchase agreement with any county, road and bridge district, or any other agency covering any road, bridge, ferry, or other transportation facility or facilities, which agreement pledges rental and purchase payments by the Department of Transportation to apply on retirement of the debt incurred or to be incurred for the construction or supplying of such transportation facility, and which debt will, in consequence of s. 344.26, be administered by the State Board of Administration, the department shall first secure from the State Board of Administration a statement approving the legal and fiscal sufficiency of such bonds or debentures and the plan for their retirement.
(2) This section shall be considered as supplementing and cumulative to existing laws and shall be effective as to any agreements entered into after June 9, 1951.