Mich. Comp. Laws § 247.438

Sec. 38. 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.