Amends GS 20-138.1 (Impaired driving) and GS 20-138.2 (Impaired driving in a commercial vehicle) to expand the offenses to include driving any vehicle or a commercial motor vehicle, respective to the offense, upon any highway, street, or public vehicular area within the State: (1) with any amount of a specified substance in the person's urine or blood, including a Schedule I controlled substance as listed in GS 90-89 or its metabolites, cocaine or its metabolites, phencyclidine (PCP) or its metabolites, methamphetamine or its metabolites, or ketamine or its metabolites; or (2) with a concentration of delta-9-tetrahydrocannabinol (THC) or its metabolites in the person's blood or urine that reaches the specified levels. Makes clarifying and technical changes. Effective December 1, 2017, and applies to offenses committed on or after that date.