Commuting in America; Developing a National Report from National Survey Sources
Penelope Weinberger, American Association of State Highway and Transportation Officials
A look at developing information from data. Translating national data surveys and sources into consumable, useful, reports.
The Commuting in America (CIA) series of reports describing travelers and their commutes to work began in April 1984, using US census data to describe the emerging patterns of commuting. The original intent of CIA was to serve as a common resource of factual information upon which policymakers could draw in shaping transportation development actions and policies. The fourth iteration of CIA, CIA 2013, consists of 16 briefs in topical areas of commuting, including The Role of Commuting in Overall Travel, Population and Worker Trends, Population and Worker Dynamic, The Nature and Pattern of Jobs, Job Dynamics, Vehicle and Transit Availability, Consumer Spending on Transportation, How Commuting Influences Travel, Commuting Mode Choice, Commuting Departure Time and Trip Time, Auto Commuting, Transit Commuting, Bicycling and Walking Commuting and Commuting Flow Patterns. The project was completed in January 2014.
Understanding commuting is a critical component of understanding total travel. Commuting travel patterns often define a large share of a household’s total trip-making as measured in share of trips. As work trips are slightly longer than trips for other purposes, work-trip commuting comprises a slightly larger share of total person travel miles. Work trips most often occur during congested time periods and are the largest contributor to travel time delay. Work trips are sensitive to and suffer the consequences of travel delay and large variations in travel time reliability.
CIA once relied on the US Census Bureau’s decennial long form data to develop reports on national commuting patterns and trends. With the advent of the American Community Survey (ACS) and subsequent discontinuation of the Decennial Long Form, the methodology for discerning national commuting trends has had to change. The two chief sources for data for CIA 2013 were the ACS and the USDOT’s National Household Travel Survey (NHTS), Additional national survey sources include the American Housing Survey of the Department of Housing and Urban Development, the Consumer Expenditure Survey of the Bureau of Labor Statistics, the administrative records-based Longitudinal Employment Household Dynamics (LEHD), the Transportation Energy Data Book, and FTA’s National Transit Database (NTD).
The US Census collects the largest, most comprehensive national data set on commuting with the “Journey to Work” questions now in the ACS. While the ACS is not a travel survey in the traditional sense, it is the source of data most used by transportation planners and modelers for demographic and commute travel behavior.
This paper follows the history of Commuting in America with an emphasis on which data were used, and how. The paper discusses the introduction and history of the journey to work question, changes from the long form to the ACS, the inclusion of other US Census and non-census data sets to discern travel trends, and ways the ACS data were used to generate information on the topics. While the paper is not a traditional research paper, it provides an historic scan and concepts for how these types of data sets can be employed to generate important, topical, accessible information for consumption by decision makers and the public. This work is of use to data providers who wish to make their data more useful and to practitioners faced with large data sets needing ideas to help turn them into information.
Association for European Transport