Skip to content U.S. Department of Transportation/Federal Highway AdministrationU.S. Department of Transportation/Federal Highway Administration
Office of Planning, Environment, & Realty (HEP)

Effective Practices

American Community Survey: New Data Source to Profile Communities

U.S. Census Bureau

Effective Practice:

New data resource to prepare more accurate, timely and comprehensive profile of America's communities.


The American Community Survey will be valuable to transportation and other government agencies, nongovernmental organizations, market researchers, academic institutions, students, and the public.


The American Community Survey (ACS) will give an up-to-date statistical picture for planning and evaluating public programs every year, not just once in ten years. Communities will be able to track changes in the well-being of children, families, and the elderly; determine the social impacts of transportation investments; evaluate programs such as welfare and workforce diversification; and monitor the effects of programs and plans that assist low-income and minority populations.

The decennial census has two parts: 1) it counts the population; and 2) for the administration of federal programs and the distribution of billions of federal dollars, it obtains demographic, housing, social, and economic information by asking a 1-in-6 sample of households to fill out a long form. Since this is done only once every 10 years, long-form information becomes out of date. Planners and other data users are reluctant to rely on it for decisions that are expensive and affect the quality of life of thousands of people. The ACS is a way to provide the data communities require every year instead of once in ten years.

The ACS is being evaluated and tested by the Census Bureau for select areas. Plans are to implement the ACS in every county of the United States with an annual sample of three million housing units. When fully operational in 2004, the ACS will provide estimates of demographic, journey-to-work, housing, social, and economic characteristics every year for all states, as well as for all cities, counties, metropolitan areas, and population groups of 65,000 people or more. For small areas and population groups of 20,000 or less, it will take five years to accumulate a large enough sample to provide estimates with accuracy similar to the decennial census. That means updated information for areas such as neighborhoods will be available starting in 2008 and every year thereafter.

The ACS will report summary data for population and housing estimates, cross tabulated by various characteristics, down to the block-group level. The summary data will be similar to the Summary Tape Files (STF) of the 1990 decennial census records, and are designed to provide statistics with greater subject and geographic detail than possible with printed reports.

The ACS will release a microdata file each year patterned after the five percent Public Use Microdata Sample (PUMS) file of the 1990 decennial census records. The microdata file allows for two different units of analysis: housing unit and person. The microdata file includes as many records as possible and shows the lowest level of geography possible within confidentiality constraints. Users of the ACS data can customize tabulations to examine the information in the way that best serves their needs. The ACS will provide more timely data for making estimates of various concepts for small geographic areas. In essence, detailed data from national household surveys (whose samples are too small to provide reliable estimates for states or localities) can be combined with data from the ACS to create reliable estimates for small geographic areas.


For the Agencies:

For the Community:


More information about the ACS at:

The American Community Survey is NOT a head count. We will still do the decennial census short form to count the population and will continue to work between censuses with states to get the yearly estimates of the population of states and counties. Because it does not count the population, the American Community Survey is NOT a means of apportioning Congressional seats. It is designed to get social, economic, and housing information every year to show trends and changes at the community level...

....We are using the word "community" in the broad sense. It refers to population subgroups as well as to geographic units like cities, states, or counties. In the past, population subgroups only received information once in 10 years; those groups tend to be too small to show any information in the national surveys which are conducted between decennial censuses. Now, we will have information every year about groups such as the oldest old (those 85 and older); teenage mothers in school and those who are working; college graduates; or specific race and ethnic groups such as Vietnamese, Mexican-Americans, and American Indian tribes.

From slideshow posted on the U.S. Census Bureau's American Community Survey website.

Logo for American Community Survey, U.S. Census Bureau

Updated: 4/13/2016
HEP Home Planning Environment Real Estate
Federal Highway Administration | 1200 New Jersey Avenue, SE | Washington, DC 20590 | 202-366-4000