The 1983 Nationwide Personal Transportation Study was the third in the NPTS series. This survey compiled national data on the nature and characteristics of travel in 1983-1984 timeframe. It addressed a broad range of travel in the United States, providing data on all personal trips by all purposes and all modes of transportation. The 1983 NPTS essentially followed the data collection design used in the 1969 and 1977 surveys. Information from a sample was collected about all trips taken during a designated 24-hour period (Travel Day). Additional detail was collected about trips of 75 miles or further (one-way) that were taken during the preceding 14-day period (Travel Period) including the 24-hour travel day. The information consists of trips and travel by purpose, mode, trip length, day-of-week, time-of-day, vehicle used, and vehicle occupancy. Data about long trips include the date on which the trip started and ended.
The Bureau of the Census conducted the 1983 NPTS (also the earlier 1969 and 1977 Surveys) under the sponsorship of several agencies of the U.S. Department of Transportation. The study was sponsored by the Federal Highway Administration, National Highway Traffic Safety Administration, the Urban Mass Transportation Administration (currently named 'Federal Transit Administration'), and the Office of the Secretary of Transportation.
Data for the 1983 NPTS was gathered between February 1983 and January 1984. The sample consisted of approximately 6,500 households, drawn from expired Current Population Survey (CPS) units and a small number of housing units built since January 1980. People in the selected households were interviewed only once. Each, month, for a year, people in a different group of households were interviewed. Each household was assigned a specific 24-hour "travel day" and collected data on all travel. "Travel days" always occurred during the first 14 days of each month during the Survey. People in the sample households were interviewed on the day following the designated travel day. The data included information about all people who were members of the sample household on the date of the Interview.
Bureau of the Census employees personally visited the people in each sample household to obtain NPTS data. The visits were preceded by a letter from the Director of the Bureau of the Census to inform each household about the Nationwide Personal Transportation Study and to solicit their cooperation. Members of the sample households were interviewed within four days of of their designated "Travel day." Household members who were absent at the time of the interview were contacted by telephone. Each person over the age of 14 was asked to report all trips they had taken during the designated 24 hour "travel day", as well as trips of 75 miles and longer (one-way distance from home to farthest point on the trip) taken during the 14 day "Travel period" ending on the "travel day." A household member, age 14 or over, was asked to report on all trips (excluding bicycling and walking trips) taken by household members between the ages of 5 and 13 years.
Collection of the 1983 NPTS data was undertaken by the Bureau of the Census' permanent professional field staff, located in 12 Regional Offices throughout the United States. Each staff member was thoroughly trained prior to beginning work on the survey. Interviewers received about three days of classroom training plus self-training materials. Additional home study materials and classroom training were planned throughout the interviewing period. Formal training was supplemented by on-the-job training sufficient to insure job performance at the level of established standards. Quality control measures, such as edition returns, observing interviews and reinterviewing selected sample households, were employed throughout the survey.
The major steps performed by the Bureau of the Census for the 1983 NPTS included editing and coding of the Questionnaire (Sections I thorough VII plus Household Information), full transcription of the data to magnetic tape; computer edit of the data to ensure completeness and consistency; calculation of the weighting factors for each household; and computation of variance and calculation of statistical reliability of the data. The Federal Highway Administration tabulated the edited and weighted data for final output of the data.
The 1983 NPTS was based on a national probability sample of approximately 7,900 households selected from each of the 50 states and the District of Columbia, and representing the total civilian noninstitutional population of the United States. However, 1,000 of these household units were found to be vacant, demolished, converted to nonresidential use, or otherwise ineligible for the survey. Of the 6,900 households eligible for interviewing, approximately 450 were not interviewed because the occupants were not home after repeated calls, refused to participate in the survey or because they were unavailable for some other reason(s). This resulted in a net of 6,438 sample households.
Almost all of the NPTS sample units had previously been interviewed for the Current Population Survey (CPS), which is conducted monthly by the Bureau of the Census for the Bureau of Labor Statistics. The CPS is designed to measure the change in the rate of unemployment using a stratified multi-stage cluster sample.
Last updated February 4, 1999