605 ILCS 5/6-127
In any county in which a county unit road district is established, the county unit district roads shall be constructed, maintained and repaired by the county superintendent of highways, subject to the direction of the county board; and with the respect to the laying out, construction, repair and maintenance of such roads, the county superintendent of highways shall have the powers and perform the duties of the highway commissioners under the provisions of this Code.
The county unit road district shall be administered as a separate county agency by the county superintendent of highways, but the presiding officer of the county board, with the advice and consent of the county board, may appoint a committee from its membership representative of the territory in such county and delegate to such committee such authority as the county board may deem proper. The county superintendent of highways may divide the territory of the county into maintenance or operational units and may employ the necessary personnel in each such unit.
605 ILCS 5/6-127