§ 530. Construction contracts. The authority shall construct the bridges pursuant to a contract or contracts. Such contracts shall be let under the supervision of the commissioner and shall be subject to his approval. Such contracts shall be let by the authority in the manner, so far as practicable, provided in § 38 of the highway law, but failure to comply with such section shall not invalidate such contracts. Requisitions for the payments to be made pursuant to such contracts shall be approved by the commissioner. The work under such contracts shall be subject to the supervision and approval of the commissioner.