Some states have laws against riding a bicycle on a street or highway while under the influence of drugs or alcohol (cycling under the influence, or CUI). Other states apply traditional DUI/DWI laws to cycling while under the influence of drugs or alcohol. And some states don't have a specific CUI law, and don't apply traditional DUI/DWI laws to riding a non-motorized vehicle, such as a bicycle.
In Illinois, the laws that apply to driving under the influence (DUI) of alcohol or drugs do not directly apply to cyclists. Illinois DUI statutes specifically refer to 'motor vehicles,' which does not include bicycles. However, local ordinances in some Illinois municipalities may have regulations regarding riding a bicycle while under the influence. Cyclists can still be stopped by law enforcement and potentially face other charges or citations if they are found to be riding unsafely due to impairment. It is important for cyclists to be aware of both state laws and local ordinances in the areas where they ride.