Drug-based DWI prosecutions in North Carolina operate under an evidentiary framework that differs substantially from alcohol enforcement. In DUI cases involving drugs (sometimes called DUID – driving under the influence of drugs) or “drugged driving” by the general public, the forensic analysis and legal issues tend to be significantly more complex.  

Unlike alcohol, for which decades of research have provided relatively clear thresholds (like 0.08 BAC) and relatively well-understood pharmacology, psychoactive drugs present a diverse and evolving challenge. 

Alcohol impairment is supported by decades of controlled laboratory research, standardized psychomotor testing models, and population-level epidemiology that correlate rising blood alcohol concentrations with relatively predictable losses of cognitive and motor functioning at certain BAC levels.