The 2001 NHTS collected information from 26,000 households nationally about both their daily and long-distance travel behavior. While many aspects of the survey are consistent across its daily and long-distance trip components, differences exist. The most important differences are the definition of a trip and the period over which data were collected. For daily travel, households were asked to record information about all the trips they took, regardless of length, on a specific day known as the travel day. A trip is generally defined as traveling from one address to another, whether it is down the street, across town, or cross country, although walking and bicycling trips for recreation, including walking the dog, where a person starts and ends at the same address were also counted. As such, this definition means a trip does not have to originate from home, such as trips from work to the doctor. Long-distance trips, by contrast, are defined as trips originating from home of 50 miles or more to the furthest destination and include the return component as well as any overnight stops and stops to change transportation mode. Participants recorded their long-distance trips over a four-week period known as the travel period.
Other minor differences exist between the daily and long-distance components of the NHTS. For instance, data collected on long-distance trips do not include travel time and the time of day the trip took place, but do include the location of overnight stops and access/egress to an airport, train station, bus station, or boat pier.