Mo. Rev. Stat. § 303.350
Notwithstanding anything else herein contained, this chapter shall not apply with respect to any motor vehicle owned by the United States, the state of Missouri, or any political subdivision of this state, or any municipality therein, nor shall this chapter apply to any common carrier or contract carrier whose operations are subject to the jurisdiction of and are regulated by the interstate commerce commission or the public service commission of Missouri, or by regulatory ordinances of the municipalities served by such common or contract carrier, and which shall have satisfied any applicable requirements concerning bond, insurance or proof of financial responsibility imposed by the regulatory authority having jurisdiction over the carrier's operations.
§ 303.350, RSMo