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 Colorado, the state's DUI (Driving Under the Influence) laws do not apply to bicycles since they are not motor vehicles. However, Colorado does have a law that prohibits riding a bicycle under the influence of alcohol or drugs. This is known as the 'bicycling under the influence' (BUI) law. Under Colorado Revised Statutes 42-4-1412 (2016), it is illegal to ride a bicycle on a roadway while under the influence of alcohol or any other drug to a degree that renders the person incapable of safely riding. The penalties for BUI are less severe than those for DUI involving motor vehicles. A person cited for BUI may face a fine but will not face jail time, and the offense does not result in points against the cyclist's driver's license. It is important for cyclists to be aware of this law to ensure their safety and the safety of others on the road.