NHTS was $10.7 million, of which $300,000 came from NHTSA and the remainder approximately equally from BTS and FHWA. In 2001, the NHTS superseded two earlier federal government surveys of personal travel in the United States. The Nationwide Personal Travel Survey (NPTS) investigated daily travel and was conducted five times between 1969 and 1995. The American Travel Survey (ATS) investigated long-distance travel and was conducted twice, once in 1977 and again in 1995.
The purpose of the NHTS is to provide information on personal travel within the United States. Detailed data from a sample of U.S. households on daily and longer-distance travel for all purposes and by all modes are expanded to provide national estimates of trips and miles by travel mode, trip purpose, and household attributes. Aside from information on journey-to-work trips reported in the Decennial Census and the American Community Survey, the NHTS is the only national source of information on the typical travel of U.S. residents. The survey provides data on the type and amount of travel, the use of various modes, the time and miles spent traveling for various purposes, ownership and use of the vehicle fleet, and relationships among household composition, life stage, and travel.
The NHTS collects data from a nationally representative sample of households to derive statistically reliable travel estimates at the national level. The size of the national sample is insufficient to provide statewide or area-specific estimates, but states and metropolitan planning organizations (MPOs) can purchase additional samples of households in their jurisdictions to support local studies. These add-on samples are surveyed as part of the larger NHTS effort. For the 2001 survey, the national sample comprised approximately 26,000 households. In addition, five state departments of transportation and four MPOs purchased supplemental samples for their local planning efforts. These supplemental samples involved a total of 40,000 additional households.
The 2001 NHTS data were collected using computer-assisted telephone interviewing (CATI) methods and a random digit dialing (RDD),