Announcement

The Federal Highway Administration is planning to enhance the 2009 NHTS Version 1.0 data in the next several months. As a result of the enhancement effort, the October 25-26 Workshop, Using National Household Travel Survey Data for Transportation Decision Making, is to be postponed. The new date for the conference is June 6-7, 2011, in the Keck Center of the National Academies, Washington, D.C. More detailed information follows immediately below.

The 2009 National Household Travel Survey (NHTS) has been on a fast track from data collection to the initial data release of Version 1.0 in January 2010. Since the publication of the Version 1.0 data, FHWA has received several inquiries and a great deal of feedback from many users throughout the nation.

A discrepancy between the numbers of nationwide transit trips reported by the NHTS and by FTA’s National Transit Database (NTD) was brought to our attention. While we do not expect that these two sources match exactly given somewhat different trip definitions, data collection techniques, and data collection limitations, we do expect them to be statistically similar once adjustments are made for such differences. What we have found is that the transit estimates from the NHTS data are higher than those made using the NTD data, which motivated us to look into the data processing methods.

While examining the data processing procedures, we paid particular attention to how we treated outliers. The results of this review led us to the decision to enhance the weights by adding more precise geographic dimensions to the raking and weight trimming steps, which should particularly reduce the effect of outliers on estimated travel. We expect that the revised weights will provide enhanced estimates for transit and potentially other estimates of travel by low-income households. The enhancement will also allow us the opportunity to use the newly released 2008 American Community Survey (ACS), which was not available at the time when the original data was collected.

The data review and enhancement process are expected to take several months – we have to do this very carefully and methodically. Consequently, we feel it is appropriate to postpone the October 25-26, 2010, Workshop Using NHTS Data for Transportation Decision Making to give participants adequate time to present results using the enhanced data. The new date for the Workshop is June 6-7, 2011, and it will still be held in Washington, D.C.

Web Site Features

Survey	Introduction	Online Table Designer	Publications	Download
				Survey Data	Trip Data at Census Tract/TAZ Level
2009 NHTS
2001 NHTS
1995 NPTS
1990 NPTS
1983 NPTS
1977 NPTS
1969 NPTS