Mich. Comp. Laws § 257.1577

Sec. 7. (1) Except as provided in subsection (2), a person operating or riding in an electric patrol vehicle shall wear a crash helmet on his or her head. The crash helmet shall meet the requirements of the rules promulgated by the department of state police under section 658 of the Michigan vehicle code, 1949 PA 300, MCL 257.658. (2) Subsection (1) does not apply to a person operating or riding in an electric patrol vehicle equipped with a roof that meets or exceeds the standards for roof-crush resistance, provided under 49 C.F.R. 571.216, or to an incapacitated person being transported to a place of safety.