Mich. Comp. Laws § 123.171
It shall be the duty of the common council of any city in this state, and of the board of trustees of any incorporated village, to cause to be constructed and maintained in such village or city not less than 1 public closet, commonly known and designated as a public convenience station, in such place or places as directed by the local board of health. Such closets or public convenience stations shall have thereon the proper signs and be so placed as directed by the local board of health as to be easily accessible from the business district or districts of such city or village, and shall be maintained in a sanitary manner under the supervision of the local board of health. Suitable and adequate accommodations shall be afforded at such public convenience station, to the members of both sexes.
MCL 123.171