OK HB3766

Creates new offense of driving under the influence of a controlled substance with two-tier threshold system: Tier 1 (5+ ng/ml active delta-9-THC) creates rebuttable presumption of impairment; Tier 2 (2-5 ng/ml) requires additional evidence of actual impairment such as field sobriety tests or Drug Recognition Expert evaluation

Specifies that non-impairing metabolites (including Carboxy-THC and other inactive metabolites) cannot constitute a per se DUI violation and are insufficient evidence for conviction without proof of actual impairment

Authorizes the Oklahoma Board of Tests for Alcohol and Drug Influence to promulgate rules adjusting THC concentration thresholds based on new scientific research

Allows registered medical marijuana patients to present evidence of lawful therapeutic use and tolerance to rebut the presumption of impairment, including medical authorization, dosage history, or expert testimony

Updates statutory references throughout Oklahoma criminal offense classifications (Class B3, B4, and C2 offenses) to reflect reorganized DUI provisions, changing subsection references from "C" to "H" and "D" to "I" in Section 11-902