37 Tex. Admin. Code § 16.62
The Commercial Driver's License Act, Texas Transportation Code, Chapter 522, defines certain motor vehicle offenses as "serious traffic violations" for the purpose of administering the Act. An improper or erratic traffic lane change is one of the definitions of a "serious traffic violation" as set out in the Act. Since an improper or erratic lane change is not an offense title in Texas, the department has designated the specific sections of the Texas Transportation Code, Chapter 545, as improper or erratic traffic lane changes for disqualification purposes pursuant to Texas Transportation Code, § 522.081. This interpretation is also meant to apply to the defensive driving section of the Texas Transportation Code, §§ 543.111 - 543.114. A conviction of either of these offenses will be considered by the department as a "serious traffic violation":
37 Tex. Admin. Code § 16.62