Proposed NCHRP Study
PROBLEM TITLE
Use of Census American Community Survey Data in Transportation
Planning
RESEARCH PROBLEM STATEMENT
The Bureau of the Census is planning to replace the
traditional decennial census "long form" with a continuous data collection
program entitled the American Community Survey (ACS). During the 1999-2001
time period the Bureau of the Census will collect American Community Survey
data in approximately 31 comparison sites in the U.S. The full implementation
of the ACS will begin in 2003.
Demographers and transportation planners at the state, metropolitan and local levels need census data for socio-economic benchmarking and in journey-to-work analyses. Much of the data used by transportation planners is derived from the traditional census long form. The ACS will be very consistent in terms of survey content, but data will be collected continuously throughout the years and the decade, rather than April 1st of the census year.
Planners will need to transition from a once-a-decade analysis paradigm to a continuous measurement paradigm. To do this, planners need guidance in analyzing the statistical characteristics of American Community Survey data for large areas (e.g., counties, places) and small areas (neighborhoods and travel analysis zones) on a time-series basis. For example, the standard errors associated with the American Community Survey may be significantly larger than the standard errors with traditional census long form data. The analyst will need to understand and explain these statistical errors to decision-makers, the public and the media. Also, differences in understanding and explaining point in time estimates versus moving averages will need to be considered. The analyst will also need to know when to report data for a single year, versus a rolling average for three-to-five years of ACS data.
PROPOSED RESEARCH
This research will complement Bureau of the Census
and US Department of Transportation efforts on analyzing ACS comparison
site data. Possible products of this research study may include guidance
manuals for statistical analysis, training courses for MPO and State DOT
staffs, detailed case studies of ACS comparison site data, and guidance
materials for presenting continuous census data to decision-makers, the
public and the media.
COST: $300,000
DURATION:
24 months