Mich. Comp. Laws § 124.463

Sec. 13. A public authority formed under this act shall be a corporate body with power to sue and be sued in any court of the state and shall be considered to be an agency and instrumentality of the state. The public authority shall possess all the powers necessary to carry out the purposes of its formation and all things incident to carrying out the purposes of its formation. The public authority shall be administered in the manner determined by the board and as provided in its articles of incorporation. The public authority by contract may employ a management firm, either corporate or otherwise, to operate the public transportation system, under the supervision of the public authority. The enumeration of powers of this act shall not be construed as a limitation on the general powers of the public authority.