Book excerpt: "Census microdata are the confidential records of specific individuals and housing units from whom Decennial Census or American Community Survey responses have been obtained. The U.S. Census Bureau also draws a sample from the full set of microdata and makes these sampled records available in the Public Use Microdata Sample (PUMS) data products, so that users can develop their own tabulations. These data are being used by state departments of transportation (DOTs) and metropolitan planning organizations (MPOs) for studies, such as analyses of the commuting characteristics of population subgroups, and for supporting travel demand model and land use models."--Preface