Mo. Const. art. IV, § 29

The highways and transportation commission shall be in charge of the department of transportation. The number, qualifications, compensation and terms of the members of the highways and transportation commission shall be fixed by law, and not more than one-half of its members shall be of the same political party. The selection and removal of all employees shall be without regard to political affiliation. The highways and transportation commission (i) shall have authority over the state highway system; (ii) shall have authority over all other transportation programs and facilities as provided by law, including, but not limited to, aviation, railroads, mass transportation, ports, and waterborne commerce; and (iii) shall have authority to limit access to, from and across state highways and other transportation facilities where the public interests and safety may require. All references to the highway commission and the department of highways in this constitution and in the statutes shall mean the highways and transportation commission and the department of transportation. [Effective - 02 Dec 2004 , see footnote]