Mich. Comp. Laws § 224.8

Sec. 8. (1) If a vacancy occurs in the office of county road commissioner, the county board of commissioners shall appoint a county road commissioner to fill the vacancy. The county road commissioner who is appointed shall hold office for the unexpired portion of the term in which the vacancy occurs. Each county road commissioner shall hold office until his or her successor is elected or appointed and qualified. (2) The county board of commissioners shall fix the compensation of county road commissioners. (3) The county board of commissioners may authorize the participation of county road commissioners in an insurance or retirement program established under section 10a. Any such authorization granted by a county board of commissioners before this subsection was added is valid. The cost of participation in the insurance or retirement program shall be paid by the county road commission from county road funds.