A person who believes they have had too much to drink to safely or legally drive may sit, lie, or fall asleep in their vehicle in a parking lot or parking space outside of a bar or restaurant, or may pull off the road and park to “sleep it off.” When the police observe a person occupying or sleeping in a parked car they may investigate if the car is illegally parked (on the side of the road or elsewhere) or for the stated purpose of checking on the well-being of the occupant of the vehicle.

After knocking on the window and attempting to wake the occupant of the vehicle the police will typically ask if the occupant was recently operating the vehicle and whether the occupant has had anything to drink. Based in part on the occupant’s answers to these questions the police may request the occupant submit to a breath or blood test, perform field sobriety tests, and may ultimately arrest the occupant for DUI/DWI.

Laws defining DUI/DWI criminal offenses vary from state to state and often include a person who is in physical control of a vehicle as being within the definition of operating a vehicle. Based on such a broad statutory definition of operating a vehicle—and depending on other factors such as (1) whether the occupant was in the driver’s seat of the vehicle or the back seat or passenger seat; (2) whether the vehicle’s engine was running; (3) whether the occupant was awake or asleep; and (4) whether the key, if any, was in the ignition—the police may arrest the occupant for DUI/DWI.

In Wyoming, DUI/DWI laws can apply to a person who is in 'actual physical control' of a vehicle, even if they are not driving it at the time. This means that if a person is found by police in a parked car and is deemed to be in physical control of the vehicle, they could potentially be arrested for DUI/DWI. Factors that law enforcement may consider include whether the person is in the driver's seat, whether the vehicle's engine is running, the person's location in the vehicle, and whether the keys are in the ignition. If an individual is found sleeping in their car, the police may investigate to determine if the car is illegally parked and to check on the well-being of the occupant. During this interaction, if the police suspect that the person has been drinking, they may ask questions, request the occupant to submit to a breath or blood test, perform field sobriety tests, and potentially arrest the person for DUI/DWI based on the evidence gathered. It is important for individuals to be aware that even if they are not driving, being in a parked car while under the influence can still lead to legal consequences under Wyoming's DUI/DWI laws.