Michigan Compiled Laws, Chapter 560. Subdivision Control Act of 1967 § 560.183

Sec. 183. (1) The county road commission may require the following as a condition of approval of final plat for all highways, streets, and alleys in its jurisdiction or to come under its jurisdiction and also for all private roads in unincorporated areas:

(2) If all improvements required under subsection (1) are not made before the final plat is submitted to the board for approval, the board nonetheless shall promptly approve the final plat if the final plat otherwise meets the requirements of this act and if the proprietor posts a deposit with the board in an amount that the board determines to be sufficient to ensure performance of the proprietor's obligation to make the required improvements within the time specified.Regardless of the deposit amount, the actual cost to complete all of the improvements remains the responsibility of the proprietor or its surety agent.

(3) The deposit required under subsection (2) shall be in the form of cash, a certified check which the board shall promptly convert to cash, or an irrevocable letter of credit, as selected by the proprietor, or a surety bond as prequalified by the state transportation department and acceptable to the board. Any surety bond shall be underwritten by a surety acceptable to the board.

(4) The board shall rebate to the proprietor, as the work progresses, amounts of any cash deposits equal to the ratio of the work completed to the entire project.

(5) The board shall reject a final plat isolating other lands of the proprietor within or adjoining the plat from existing public streets or roads unless the proprietor provides suitable access by easement or suitable access dedicated to public use.

(6) As used in this section, “county road commission” means the board of county road commissioners elected or appointed pursuant to section 6 of chapter IV of 1909 PA 283, MCL 224.6, or, in the case of a charter county with a population of 2,000,000 or more with an elected county executive that does not have a board of county road commissioners, the county executive for ministerial functions and the county commission provided for in section 14(1)(d) of 1966 PA 293, MCL 45.514, for legislative functions.