The foregoing sections of this act shall be deemed to provide an additional and alternative method for the doing of the things authorized thereby, and shall be regarded as supplemental and additional to powers conferred by other laws: Provided, however, That the issuance of highway bonds or highway refunding bonds under the provisions of this act need not comply with the requirements of any other law applicable to the issuance of bonds, notes or other obligations.

Except as otherwise expressly provided in this act, none of the powers granted to the secretary of transportation under the provisions of this act shall be subject to the supervision or regulation or require the approval or consent of any municipality or political subdivision or any commission, board, bureau, official or agency thereof or of the state.