Rhode Island has no statutory per se THC blood limit for driving. Unlike alcohol DUI where 0.08 percent BAC is automatic per se DUI, marijuana DUI requires the prosecution to prove actual impairment of driving ability rather than just presence of THC in the body. This is a significant defense advantage in marijuana DUI cases because THC can remain detectable in blood and urine for days or weeks after use without producing any current impairment. The prosecution must show through officer observations, field sobriety performance, and other evidence that you were actually impaired while driving, not simply that you used marijuana at some point.
