(a) If requested by an authority, the department may agree to assume all or part of the duty to maintain or operate a turnpike project or ferry of the authority.
(b) The authority shall reimburse the department for necessary costs of maintaining or operating the turnpike project or ferry as agreed by the department and the authority.
(c) Money received by the department under Subsection (b) shall be deposited to the credit of the state highway fund and is exempt from the application of Sections 403.095 and 404.071, Government Code.
(d) If the department assumes all of the duty to maintain or operate a turnpike project or ferry under Subsection (a), the authority is not liable for damages resulting from the maintenance or operation of the turnpike project or ferry.
(e) An agreement under this section is not a joint enterprise for purposes of liability.