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.

     Any act or proceeding herein directed or authorized to be performed or conducted by the state highway commissioner, may be done by said commissioner in person, or by 1 of his deputies or by any other person generally or specifically deputized by him for the doing of such work. Any determination made by such deputy, or any hearing or other proceeding conducted by him shall be deemed to be for the purpose of this act, and have the same legal force and significance as though personally performed by said commissioner.

     All highways improved under the provisions of this act by the county road commissioners, or by the state highway commissioner, where more than 1 county is affected, that are parts of county roads shall be and remain under the jurisdiction of the county road commissioners of the county in which such highway is situate. Any township road improved hereunder shall be and remain subject to the jurisdiction or authority of the proper township officials after such improvement: Provided, however, That in all cases, the jurisdiction of the county and township officials shall be subject to the right to make proper repairs out of the maintenance fund, if any, hereinbefore provided for. In any highways improved along a county line, jurisdiction over the portion improved shall remain the same as though no improvement had been made upon such highway.