What is NHTS?
The 2001-2002 National Household Travel Survey (NHTS) is a national survey of daily and long-distance travel. The survey includes demographic characteristics of households, people, vehicles, and detailed information on daily and longer-distance travel for all purposes by all modes. NHTS survey data are collected from a sample of U.S. households and expanded to provide national estimates of trips and miles by travel mode, trip purpose, and a host of household attributes. Past daily travel surveys were conducted in 1969, 1977, 1983, 1990 and 1995, providing a source of detailed information on personal travel patterns in the U.S. Long-distance travel information was collected in 1977 and 1995. The 2001-2002 NHTS combines questions about daily and long-distance trips in one survey.
Why Collect NHTS Data?
The National Household Travel Survey provides the only authoritative source of information at the national level on the relationships between the characteristics of personal travel and the demographics of the traveler. These relationships provide a foundation to better understand how the Nation’s transportation systems serve the American public.
The 2001-2002 NHTS data can be used to investigate topics in transportation safety, congestion, mobility of various population groups, the relationship of personal travel to economic productivity, the impact of travel on the human and natural environment, and other important subjects. These data provide planners and decision makers with up-to-date information to assist them with effectively improving the mobility, safety, and security of our Nation’s transportation systems. Trends and changes in travel behavior can be identified and understood by analyzing the data series, which for daily travel now encompasses more than 30 years.
Who is Included in the Survey?
The NHTS collected travel data from a national sample of the civilian, non-institutionalized population of the United States. People living in college dormitories, nursing homes, other medical institutions, prisons, and military bases were excluded from the sample.
There are approximately a total of 66,000 households in the final 2001-2002 NHTS dataset. About 26,000 households are in the national sample, while the remaining 40,000 households are from nine add-on areas.
What is an Add-On?
Since the NHTS is a national survey, it collects data from a nationally representative sample of households to derive statistically reliably travel estimates at the national level. Sample data in the NHTS are not adequate to provide statewide, or area-specific estimates. For certain states and local jurisdictions interested in developing travel estimates for their specific areas, additional household interviews were conducted to enlarge their sample size. The jurisdictions that purchased these additional samples are referred to as the “add-on” areas. In the 2001-2002 NHTS, there are nine add-on areas:
How was the NHTS Conducted?
The 2001-2002 NHTS was conducted using Computer-Assisted Telephone Interviewing (CATI) technology. Each household in the sample was assigned a specific 24-hour “Travel Day” and kept diaries to record all travel by all household members for the assigned day. A 28-day “Travel Period” was assigned to collect longer-distance travel (over 50 miles from home) for each household member, and includes information on long commutes, airport access, and overnight stays. The assigned travel day was the last day of the assigned travel period.
When were the data collected?
The NHTS interviews were conducted from April 2001 through May 2002.
The 2001-2002 NHTS was sponsored by three agencies within the U. S. Department of Transportation: the Bureau of Transportation Statistics (BTS), the Federal Highway Administration (FHWA), and the National Highway Traffic Safety Administration. It integrates two previous national travel surveys: the FHWA’s- Nationwide Personal Transportation Survey and BTS’ American Travel Survey.