Mich. Comp. Laws § 247.957

Sec. 7. After a 30-day comment period and an opportunity for a public hearing, the department may make additions, deletions, or changes in the Pure Michigan byway system for 1 or more of the following reasons: (a) By resolution, the governing body of a county or city requests that a particular named route lying within its jurisdictional boundaries be added to or deleted from the Pure Michigan byway system. The department shall not add a route to the system if the governing body of a county or city adopts a resolution requesting that a route not be added. The department shall remove a route from the system within 1 year after a resolution is adopted by a county or city requesting removal. (b) The department proposes to add or delete any named route or portion of a route to the Pure Michigan byway system. (c) The department proposes any action that would result in a change in the scenic, historical, or recreational character of any route on the Pure Michigan byway system that is determined to be substantial by the department.