Yes. Recreational cannabis legalization did not eliminate DUI liability. A driver over 21 who legally purchased cannabis at a licensed Illinois dispensary can still be charged under 625 ILCS 5/11-501 if THC blood concentration hits 5 ng/mL or if actual impairment is shown. Legality of possession and legality of driving are separate legal questions. The chicagoduilawyer.net network sees a common client pattern: consumption at home the night before, morning commute, traffic stop, blood draw still shows residual THC. Legal purchase does not shield against per se detection windows that outlast psychoactive effect.
