The Kansas turnpike authority is hereby authorized to contract for the services as set out in Kan. Stat. Ann. § 68-2021, which contracts shall provide, on behalf of the Kansas turnpike authority as follows: (1) That it shall reimburse the secretary of transportation out of the proceeds of the sale of bonds for any such project or, from any other funds available for the purpose, the amount so expended by the secretary on said particular project for such services rendered prior to the sale of such turnpike revenue bonds, and (2) it shall pay to the secretary of transportation, as billed by the secretary, all charges made for such services done and rendered as a part of or necessary to the construction of such project.