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 Delaware, the laws that apply to driving under the influence (DUI) of alcohol or drugs also apply to cycling under the influence (CUI). Delaware Code Title 21, Section 4177, prohibits operating a vehicle while under the influence of alcohol or drugs. The term 'vehicle' under Delaware law is broad enough to include bicycles. Therefore, a person can be charged with a DUI while riding a bicycle if they are found to be under the influence of alcohol or drugs to a degree which impairs their ability to ride safely. It is important for cyclists in Delaware to be aware that the same legal standards and potential penalties that apply to motor vehicle drivers when it comes to DUI can also apply to them.