All about safety:  Temporary Campaign Signs must be placed properly in the Right-of-Way

Road Commission of Kalamazoo County (RCKC):

The placement of temporary wire campaign signs within the right-of-way (county road right-of-way is typically 33 feet from the centerline) must not obstruct vision, especially at intersections. The placement of a large temporary sign supported more permanently in the ground is not allowed. Campaign signs that do not meet these criteria will be removed. Candidates are responsible for obtaining approval from adjacent property owners before placing signs, If the placement of a temporary sign is in the right-of-way and the property owner does not prefer that the sign be placed there, they should be immediately removed. Signs must be removed after the election.

Michigan Department of Transportation (MDOT):

Signs must be placed more than 30 feet from the edge of the roadway (or from the white line along the edge on highways) without barrier-type curbs. On highways that do have barrier curbs, the signs must be more than 3 feet from the back of the curb. Signs are not allowed within clear vision areas at intersections or commercial driveways, or within limited access rights of way. Campaign signs that do not meet these criteria will be removed. Candidates are responsible for obtaining approval from adjacent property owners before placing signs. Signs must be removed within 10 days after the election.

Courtesy of MDOT Press Release