(a) An authority may pay the expenses of studying the cost and feasibility and any other expenses relating to the preparation and issuance of bonds for a proposed turnpike project or system by:
(1) using legally available revenue derived from an existing turnpike project or system;
(2) borrowing money and issuing bonds or entering into a loan agreement payable out of legally available revenue anticipated to be derived from the operation of an existing turnpike project or system; or
(3) pledging to the payment of the bonds or loan agreements legally available revenue anticipated to be derived from the operation of an existing turnpike project or system or revenue legally available to the authority from another source.
(b) Money spent under this section for a proposed turnpike project or system must be reimbursed to the turnpike project or system from which the money was spent from the proceeds of bonds issued for the acquisition and construction of the proposed turnpike project or system.
(c) The use of any money of a turnpike project or system to study the feasibility of another turnpike project or system or used to repay any money used for that purpose does not constitute an operating expense of the turnpike project or system producing the revenue and may only be paid from the surplus money of the turnpike project or system.