Search Results Use the search box below to revise your search, or start a new search. Studies (2) Variables Publications Your query returned 2 studies. Series results are grouped under the most relevant study. Ungroup series results to view all results. Sort by: Study Relevance Title A-Z Released/Updated Time Period Most Cited in ICPSR Bib. Variable Relevance 1. National Household Travel Survey, 2001: [United States] (ICPSR 4047) United States Department of Transportation. Federal Highway Administration 2. Japanese General Social Survey (JGSS), 2006 (ICPSR 25181) Tanioka, Ichiro; Iwai, Noriko; Nitta, Michio; et al.