Mich. Comp. Laws § 247.437
In case a petition is presented to the state highway commissioner where authority to act is hereby vested in the board of county road commissioners of the county wherein such road is situated, such petition shall be immediately transmitted to said board and action thereon is hereby authorized as though the said petition had been properly addressed and presented in the first instance. Should a petition be presented to these county road commissioners for the improvement of any highway, in any county, and in the judgment of the county road commissioners, there should be lands liable to an assessment for benefits situate in any other county, then the county road commissioners shall certify such petition to the state highway commissioner, who shall thereupon proceed to act upon the same as though the said petition had been addressed to him in the first instance.
MCL 247.437