Mo. Rev. Stat. § 91.840

All such cities are hereby authorized and empowered by ordinance to create and establish a rapid transit commission and determine the number of members thereof, or, in lieu of such commission, create the office of rapid transit commissioner; provide for the appointment and removal of such commission or commissioner, prescribe their qualifications, fix their term of office and compensation, define their powers and duties, provide for the employment of assistants, and do all other things necessary for the proper and efficient functioning of such commissioner or commission, and for carrying out effectively the provisions of sections 91.780 to 91.840.