Maryland, like most states, makes it illegal to drive with an open container of alcohol. This includes beer, wine, and liquor. An open container is defined as an alcoholic beverage that has been partially consumed, where the seal has been broken, or is open.

There are exceptions if the bottle is in the trunk or a locked glove compartment. My recommendation is always to keep alcoholic beverages in the trunk and there should be no issues. There are also exceptions for vehicles for hire (taxi cabs, Uber, etc.) and RV's. A driver also cannot be held liable for a passenger having an open container.

Many counties also have local laws prohibiting open containers on streets, sidewalks, and beaches. Anyone violating these laws can be fined.