MO Rev Stat § 304.820 (2021)
2021 Missouri Revised Statutes|Title XIX - Motor Vehicles, Watercraft and Aviation|Chapter 304 - Traffic Regulations|Section 304.820 - Text messaging and using a hand-held mobile device while operating a motor vehicle prohibited, when — exceptions — definitions — violation, penalty.

Effective - 28 Aug 2013, 2 histories   304.820. Text messaging and using a hand-held mobile device while operating a motor vehicle prohibited, when — exceptions — definitions — violation, penalty. — 1. Except as otherwise provided in this section, no person twenty-one years of age or younger operating a moving motor vehicle upon the highways of this state shall, by means of a hand-held electronic wireless communications device, send, read, or write a text message or electronic message.  2. Except as otherwise provided in this section, no person shall operate a commercial motor vehicle while using a hand-held mobile telephone.  3. Except as otherwise provided in this section, no person shall operate a commercial motor vehicle while using a wireless communications device to send, read, or write a text message or electronic message.  4. The provisions of subsection 1 through subsection 3 of this section shall not apply to a person operating:  (1) An authorized emergency vehicle; or  (2) A moving motor vehicle while using a hand-held electronic wireless communications device to:  (a) Report illegal activity;  (b) Summon medical or other emergency help;  (c) Prevent injury to a person or property; or  (d) Relay information between a transit or for-hire operator and that operator's dispatcher, in which the device is permanently affixed to the vehicle.  5. Nothing in this section shall be construed or interpreted as prohibiting a person from making or taking part in a telephone call, by means of a hand-held electronic wireless communications device, while operating a noncommercial motor vehicle upon the highways of this state.  6. As used in this section, "electronic message" means a self-contained piece of digital communication that is designed or intended to be transmitted between hand-held electronic wireless communication devices. "Electronic message" includes, but is not limited to, electronic mail, a text message, an instant message, or a command or request to access an internet site.  7. As used in this section, "hand-held electronic wireless communications device" includes any hand-held cellular phone, palm pilot, blackberry, or other mobile electronic device used to communicate verbally or by text or electronic messaging, but shall not apply to any device that is permanently embedded into the architecture and design of the motor vehicle.  8. As used in this section, "making or taking part in a telephone call" means listening to or engaging in verbal communication through a hand-held electronic wireless communication device.  9. As used in this section, "send, read, or write a text message or electronic message" means using a hand-held electronic wireless telecommunications device to manually communicate with any person by using an electronic message. Sending, reading, or writing a text message or electronic message does not include reading, selecting, or entering a phone number or name into a hand-held electronic wireless communications device for the purpose of making a telephone call.  10. A violation of this section shall be deemed an infraction and shall be deemed a moving violation for purposes of point assessment under section 302.302.  11. The state preempts the field of regulating the use of hand-held electronic wireless communications devices in motor vehicles, and the provisions of this section shall supercede any local laws, ordinances, orders, rules, or regulations enacted by a county, municipality, or other political subdivision to regulate the use of hand-held electronic wireless communication devices by the operator of a motor vehicle.  12. The provisions of this section shall not apply to:  (1) The operator of a vehicle that is lawfully parked or stopped;  (2) Any of the following while in the performance of their official duties: a law enforcement officer; a member of a fire department; or the operator of a public or private ambulance;  (3) The use of factory-installed or aftermarket global positioning systems (GPS) or wireless communications devices used to transmit or receive data as part of a digital dispatch system;  (4) The use of voice-operated technology;  (5) The use of two-way radio transmitters or receivers by a licensee of the Federal Communications Commission in the Amateur Radio Service. ­­-------- (L. 2009 H.B. 62, A.L. 2013 H.B. 103)