A passenger is a person who is traveling in a vehicle such as a car, bus, train, plane, or ship, but who is neither driving it nor working on it.
"a person who is travelling in a car, bus, train, plane or ship and who is not driving it or working on it"
This term specifically refers to individuals who occupy a mode of transportation without being involved in its operation.
Author's summary: A passenger is someone who travels in a vehicle without participating in its driving or work, simply riding along for the journey.