Mo. Rev. Stat. § 229.210
It shall be unlawful for any person to drive a vehicle, an animal or animals or a load of any kind upon a highway bridge or culvert recently constructed or repaired wholly or partly of concrete or upon the surface of any improved highway of macadam, concrete, brick or bituminous material; and which has not been opened to traffic after the construction or repair, by order of the county highway engineer of the county in which such bridge or culvert or improved highway is situated, or by order of any other person having charge of the construction or repair of said bridge or culvert or improved highway; provided, due notice to the public has been given that the bridge or culvert or improved highway is closed to traffic, by placing barriers across the entrances to the bridge or culvert or improved highway and by written or printed handbills placed at either entrance to the bridge or culvert or improved highway stating that the bridge or culvert or improved highway is closed to traffic and mentioning the date on which same will be opened to traffic signed by the county highway engineer or by the person in charge of the construction or repair of the bridge or culvert or improved highway.
§ 229.210, RSMo