Mich. Comp. Laws § 124.467

Sec. 17. Public transportation service, including any public transportation system and public transportation facilities, may be financed by the public authority by any 1 or more of the following means: (a) By service charges, fees, or fares to users of the public transportation services. (b) By funds disbursed by the state to the public authority and usable by the public authority. (c) By any other income or revenue, including appropriations or contributions, or other revenue of the members of the public authority and any political subdivisions. (d) By grants, loans, appropriations, payments, or contributions from the federal government, this state, another state or other governmental units and grants, contributions, gifts, devises, or bequests from public or private sources. (e) By proceeds of ad valorem taxes, special assessments, or charges imposed pursuant to law and collected by the state or a political subdivision or the public authority and returned or paid to the public authority pursuant to law or contract. (f) By proceeds of an income tax as may be provided by law. (g) By issuance of bonds or notes as provided by this act. (h) By means of land contracts, installment purchase contracts, or leases authorized by this act.