In most jurisdictions, laws have been enacted that dictate the legal obligations of the owner of a vehicle or vessel, or of the driver or pilot of the same, towards the passengers. With respect to passengers riding in cars and vans, the driver may owe a duty of care to passengers, particularly where the passenger's presence in the vehicle can be seen to "confer some benefit on the driver other than the benefit of his or her company or the mere sharing of expenses". In other situations, however, guest statutes may limit the ability of passengers to sue the driver of the vehicle over an accident. Many places require cars to be outfitted with measures specifically for the protection of passengers, such as passenger-side air bags. With respect to passengers on commercial vehicles or vessels, both national laws and international treaties require that the carrier act with a certain standard of care. The number of passengers that a vehicle or vessel may legally carry is defined as its seating capacity.