Driving under the influence of drugs or alcohol is prohibited in every state. But most states also make it illegal for drivers and passengers to possess open containers of alcohol in a vehicle. And the open container laws of some states even apply to containers of marijuana.
In most states, a person commits an open container violation by possessing an open container of alcohol in the passenger area of a vehicle. (Many open container laws also prohibit drinking alcohol in a vehicle.) Drivers and passengers are subject to the restriction. And the vehicle doesn't have to be in motion for a person to be cited for an open container violation: Open Container laws generally apply to vehicles that are in motion and parked.
In many states that have legalized marijuana for recreational or medical use, there are laws that prohibit possessing an open container of marijuana in a vehicle. Generally, these laws mirror their alcohol-open-container counterparts.
State laws vary somewhat. But the laws of most states define "open container" as any alcoholic beverage that has a broken seal, has been opened, or has had some of the contents removed. It's also common for state laws to exempt alcoholic beverages that contain a very small amount of alcohol such as non-alcoholic beer and kombucha.
Open container laws prohibit possession of open containers in a vehicle. So it's technically the person—whether the driver or a passenger—with actual possession of the alcoholic beverage who's responsible.
But of course, if an officer finds an open container in a vehicle and no one owns up to it being theirs, it might be hard to determine who was actually in possession of the beverage. In such a case, the officer might look to circumstances like who was closest to the container and whether the container was within reach of one or more persons. It might even be possible for more than one person to be cited for a single open container in a car.
There are also states that make the driver responsible for all open container violations within the vehicle.
Open container restrictions typically apply only to the passenger area of a vehicle. Basically, the passenger area of a vehicle includes all areas that might be occupied or within reach of the driver or a passenger. So, putting an open container in the trunk of a vehicle is usually a safe bet. And for cars without trunks, the laws of some states allow open containers behind the last row of seating.
Open container laws also normally have exceptions. For example, most states allow open container in the living area of a motorhome and in the passenger areas of vehicles-for-hire such as limousines and party buses.
The penalties for open container violations vary by state. However, the consequences are generally far less serious than those for a DUI conviction. Typically, an open container ticket carries only a small to moderate fine—normally about $100 or less. Although jail time is a possibility in some states, it's probably quite unlikely that an open container conviction would actually result in a person going to jail.