Vehicle Occupancy

The number of people aboard a vehicle at a given time; also known as auto or automobile occupancy when the reference is to automobile travel only. (TRB1)

The number of persons, including driver and passenger(s) in a vehicle; also includes persons who did not complete a whole trip. Nationwide Personal Transportation Survey (NPTS) occupancy rates are generally calculated as person miles divided by vehicle miles. (FHWA3)