Mo. Rev. Stat. § 300.135

All traffic control signs, signals and devices shall conform to the manual and specifications approved by the state highways and transportation commission or resolution adopted by the legislative body of the city. All signs or signals required hereunder for a particular purpose shall so far as practicable be uniform as to type and location throughout the city. All traffic control devices so erected and not inconsistent with the provisions of this ordinance shall be official traffic control devices.