A passenger is a person who travels in a vehicle but bears little or no responsibility for the tasks required for that vehicle to arrive at its destination or otherwise operate the vehicle. The vehicles may be bicycles, buses, passenger trains, airliners, ships, ferryboats, and other methods of transportation. Crew members, as well as the driver or pilot of the vehicle, are usually not considered to be passengers. For example, a flight attendant on an airline would not be considered a passenger while on duty and the same with those working in the kitchen or restaurant on board a ship as well as cleaning staff, but an employee riding in a company car being driven by another person would be considered a passenger, even if the car was being driven on company business.
Railways
In railway parlance, passenger, as well as being the end user of a service, is also a categorisation of the type of rolling stock used. In the British case, there are several categories of passenger train. These categories include:
Local passenger, the lowest category of British passenger train, which provides a service that stops at all stations between major destinations, for the benefit of local populations.
No pax
In transportation, a "no pax" trip is a trip without passengers. For example, no-pax flights are freight, ferry, repositioning cruises and positioning flights.
Legal status
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.
Revenue passenger miles and revenue passenger kilometers are measures of traffic for an airline flight, bus, or train calculated by multiplying the number of revenue-paying passengers aboard the vehicle by the distance traveled. On long-distance buses and trains, passengers may board and disembark at intermediate stops, in which case RPMs/RPKs have to be calculated for each segment if a careful total is needed. Revenue passenger miles can be considered the basic amount of "production" that an airline creates. The revenue passenger miles can be compared to the available seat miles over an airline's system to determine the overall passenger load factor. These measurements can further be used to measure unit revenues and unit costs.