(a) In this section:
(1) “Electronic message” means data that is read from or entered into a wireless communication device for the purpose of communicating with another person.
(2) “Wireless communication device” has the meaning assigned by § 545.425.
(b) An operator commits an offense if the operator uses a portable wireless communication device to read, write, or send an electronic message while operating a motor vehicle unless the vehicle is stopped. To be prosecuted, the behavior must be committed in the presence of or within the view of a peace officer or established by other evidence.

(c) It is an affirmative defense to prosecution of an offense under this section that the operator used a portable wireless communication device:
(1) in conjunction with a hands-free device, as defined by § 545.425;
(2) to navigate using a global positioning system or navigation system;
(3) to report illegal activity, summon emergency help, or enter information into a software application that provides information relating to traffic and road conditions to users of the application;
(4) to read an electronic message that the person reasonably believed concerned an emergency;
(5) that was permanently or temporarily affixed to the vehicle to relay information in the course of the operator’s occupational duties between the operator and:
(A) a dispatcher; or
(B) a digital network or software application service; or
(6) to activate a function that plays music.
(d) Subsection (b) does not apply to:
(1) an operator of an authorized emergency or law enforcement vehicle using a portable wireless communication device while acting in an official capacity; or
(2) an operator who is licensed by the Federal Communications Commission while operating a radio frequency device other than a portable wireless communication device.
(e) An offense under this section is a misdemeanor punishable by a fine of at least $25 and not more than $99 unless it is shown on the trial of the offense that the defendant has been previously convicted at least one time of an offense under this section, in which event the offense is punishable by a fine of at least $100 and not more than $200.
(f) Notwithstanding Subsection (e), an offense under this section is a Class A misdemeanor punishable by a fine not to exceed $4,000 and confinement in jail for a term not to exceed one year if it is shown on the trial of the offense that the defendant caused the death or serious bodily injury of another person.
(g) If conduct constituting an offense under this section also constitutes an offense under any other law, the person may be prosecuted under this section, the other law, or both.
(h) The Texas Department of Transportation shall post a sign at each point at which an interstate highway or United States highway enters this state that informs an operator that:
(1) the use of a portable wireless communication device for electronic messaging while operating a motor vehicle is prohibited in this state; and
(2) the operator is subject to a fine if the operator uses a portable wireless communication device for electronic messaging while operating a motor vehicle in this state.
(i) A peace officer who stops a motor vehicle for an alleged violation of this section may not take possession of or otherwise inspect a portable wireless communication device in the possession of the operator unless authorized by the Code of Criminal Procedure, the Penal Code, or other law.
(j) This section preempts all local ordinances, rules, or other regulations adopted by a political subdivision relating to the use of a portable wireless communication device by the operator of a motor vehicle to read, write, or send an electronic message.