Mich. Comp. Laws § 67.11: Sidewalks; regulation of things on, over and under.

Sec. 11.

The council shall have power to regulate and prohibit the placing of signs, awnings, awning posts and other things upon or over sidewalks, and to regulate or prohibit the construction and use of openings in the sidewalks, and of all vaults, structures and excavations under the same.