Census population data are used in many transportation planning applications including population forecasting, travel demand modeling and microsimulation, Title VI analysis and land use analysis. The US Census definition of "urbanized areas" is used in the Federal determination of Metropolitan Planning Organizations (MPOs). Planning (PL) and Surface Transportation Program (STP) funds are based upon urbanized area populations. The transportation planning community, through American Association of State Highway and Transportation Officials (AASHTO), contracts for a special tabulation from Census data called the Census Transportation Planning Products (CTPP). The CTPP focuses on the journey-to-work, and other tables helpful for transportation planning (including household size, household income, mode usage, and vehicle availability).
A profile includes four tables that provide various demographic, social, economic, and housing characteristics for the states, counties, minor civil divisions in selected states, places, metropolitan areas, and congressional districts. It includes 100 percent and sample data from the decennial censuses. Some of the variables reported include household income, vehicles available in households, average travel time, Means of transportation to work.
Summary File 1 (SF1) contains the data compiled from the questions asked of all people and about every housing unit. Population items include sex, age, race, Hispanic or Latino origin, household relationship, household type, household size, family type, family size, and group quarters. Housing items include occupancy status, vacancy status, and tenure (whether a housing unit is owner-occupied or renter-occupied).
Small area (Census block) population counts by race and national origin are now available from the Census Bureau. These files are known as "Redistricting data" or the "PL-94-171 data". The files are based on 100 percent count and contain the most detailed information on the location of the total population by race and Hispanic/Latino origin, and population over the age of 18 (voting population) by race and Hispanic/Latino origin.
The PL-94-171 data constitute an important source for recent transportation planning concerns such as Environmental Justice (EJ) analysis because of the detailed race and ethnicity variables on the file. The file contains extensive data on race and ethnicity, so it can be used to analyze the concentrations of minority population groups.
The 2010 Urban Area boundaries can be examined using the UA Census 2010 TIGER/Line files.
