Why is the Census 2000 Public Use Microdata Sample (PUMS) important to transportation planners?
PUMS 2000 contain records for a sample of housing units with information on the characteristics of each unit and each person in it. While preserving confidentiality (by removing identifiers), these microdata files permit users to prepare virtually any tabulation. Several transportation programs use PUMS data. For example, TRANSIMS is a microsimulation project being developed by DOT and EPA, with technical work conducted by the DOE Los Alamos National Laboratory. This is a multi-year $40 million effort to replace the 40-year old four-step travel demand system. Because it is a microsimulation, it relies on microdata to populate households along street segments. Thus, it is critical that a large microdata file is available that includes age, gender, earnings, household income and number of vehicles, travel mode to work, travel time and departure time.
