All such openings, excavations, maintenance and/or obstructions shall be properly and substantially barricaded, signed and marked at the contractor’s expense pursuant to the Manual of Traffic Controls for Street and Highway Construction and/or Maintenance Operations by the Michigan Department of State Highways, Traffic Control Devices, or any applicable successor document thereto, specifically pursuant to §§ 6-Al, 6-A2, 6-A3, 6-A4, and 6-A5, which sections of the Municipal Department of State Highways Manual are incorporated herein by reference and made a part hereof.
(1990 Code, § 4.32)