Information Quality

Monday, September 10, 2012

BTS obtained the data in this report from many sources, including other federal agencies, private industry, and trade associations. Data based on surveys are subject to sampling variability. Data from all sources may be subject to omissions and errors in reporting, recording, and processing. The sources cited for each table often provide additional information about the definitions, methodologies, and statistical reliability.

Under Office of Management Budget (OMB) directives, data collected by federal agencies are subject to guidelines, policies, and practices for disseminating statistics to the public.

Because federal agencies are subject to these guidelines, BTS relies heavily on federal sources for the data contained within this report. Federal agencies, both within and outside of the U.S. Department of Transportation (U.S. DOT), collect, compile, analyze, and publish transportation data. A partial list of these organizations is included in box A. In some cases, these agencies compile and disseminate data submitted or reported by state and local governments and/or by private industry on transportation operations, planning, financing, or management. Furthermore, some federal agencies conduct surveys or otherwise directly collect data on specific matters, either through their own auspices or through partnerships with other entities. In addition, other agencies produce data or information relevant to transportation, even though transportation is not their primary focus.

OMB chairs an interagency statistical policy committee, comprised of the heads of 13 statistical agencies in the federal government, including BTS. This group develops and distributes these statistical policies and guidelines for best practices to these and other agencies involved in statistics.

In response to its legislative mandates, BTS has developed guidelines for good statistical practices in the transportation field. Specific topics covered include planning data systems, collecting data, processing data, dissemination of information, and evaluation of information quality. These guidelines apply to all information, including compilations containing data from other sources, appearing in BTS publications. Box B discusses various federal statistical quality manuals and guidelines pertinent to transportation data.

Agencies also often have their own specific requirements and guidelines in addition to government-wide guidance. For example, they may issue guidelines for data reporting by state agencies, localities, and transportation providers. Such guidance may contribute to greater uniformity, comparability, and quality of the resulting data even though it comes from multiple providers.

In many, but by no means all cases, source agencies document the methods used in collecting, compiling, and assuring the quality of the data they produce. In many cases, the cited agencies publish source and accuracy statements. The BTS website for National Transportation Statistics, a web-based companion document to this report, summarizes much of this information with respect to particular data series (National Transportation Statistics, Appendix E-Data Source and Accuracy Statements, http://www.bts.gov/publications/national_transportation_statistics/ ).

Box A: Selected Federal Agencies that Collect or Compile Transportation Data

Multimodal Data (including economic data)

Bureau of Economic Analysis, USDOC
Bureau of Labor Statistics, USDOL
Bureau of Transportation Statistics (Research and Innovative Technology Administration), USDOT
Customs and Border Protection, USDHS
U.S. Census Bureau, USDOC

Aviation Data

Bureau of Transportation Statistics (Research and Innovative Technology Administration), USDOT
Federal Aviation Administration, USDOT
Office of Aviation and International Affairs, USDOT
National Transportation Safety Board

Hazardous Materials

Data Pipeline and Hazardous Materials Administration, USDOT
U.S. Census Bureau, USDOC
Bureau of Transportation Statistics (Research and Innovative Technology Administration), USDOT

Highway Data

Federal Highway Administration, USDOT
Federal Motor Carrier Safety Administration, USDOT
Federal Transit Administration, USDOT
National Highway Traffic Safety Administration, USDOT

Maritime and Inland Waterways Data

Maritime Administration, USDOT
Federal Maritime Commission
Saint Lawrence Seaway Development Corporation, USDOT
U.S. Army Corps of Engineers
U.S. Coast Guard, USDHS

Pipeline Data

Pipeline and Hazardous Materials Administration, USDOT

Railroad Data

Federal Railroad Administration, USDOT
Surface Transportation Board, USDOT

Transit Data

Federal Transit Administration, USDOT

Other Agencies Collecting Data Related to Transportation

Agricultural Marketing Service, USDA
Environmental Protection Agency
Energy Information Administration, USDOE

KEY: USDHSU.S. Department of Homeland Security; USDAU.S. Department of Agriculture; USDOCU.S. Department of Commerce; USDOEU.S. Department of Energy; USDOLU.S. Department of Labor; USDOTU.S. Department of Transportation

Box B: Information Quality Guidelines for Federal Transportation Data

As a federal statistical agency, the Bureau of Transportation Statistics (BTS) has its own statistical standards and participates with other agencies to improve statistical information quality. Under an array of guidelines, other federal agencies collect, compile, and disseminate statistical data. The following are key guidelines and statistical information quality documents:

BTS Statistical Standards Manual-covers all aspects of RITA/BTS statistical practice: (http://www.bts.gov/programs/statistical_policy_and_research/bts_statistical_standards_manual/index.html).
Guide to Good Statistical Practice in the Transportation Field-includes the DOT guidelines for statistical information and additional BTS guidance for good statistical practice: (http://www.bts.gov/publications/guide_to_good_statistical_practice_in_the_transportation_field/).
Guidelines for Ensuring and Maximizing the Quality, Objectivity, Utility, and Integrity of Informa tion Disseminated by Federal Agencies-Federal Register Notice, vol. 67, no. 36, Feb. 22, 2002, Part IX - Office of Management and Budget: (http://www.bts.gov/publications/federal_register_notice/pdf/volume_67_number_36.pdf).
Guidelines of the Federal Statistical Organizations-an approach to guidelines for statistical information adopted by the Interagency Council on Statistical Policy (ICSP): (http://www.bts.gov/publications/federal_register_notice/pdf/volume_67_number_107.pdf).
DOT Report for Implementing OMB's Information Dissemination Quality Guidelines -is the DOT implementation of the OMB information quality guidelines and correction procedures. The DOT guidelines permit its agencies to issue their own guidelines, if these guidelines are consistent with the overall DOT guidelines: (http://docketsinfo.dot.gov/ombfinal092502.pdf).
Standards and Guidelines for Statistical Surveys-adopted September 2006: (http://www.whitehouse.gov/omb/inforeg/statpolicy/standards_stat_surveys.pdf).
Title V-Confidential Information Protection and Statistical Efficiency Act of 2002-effective Dec. 17, 2002: (http://www.whitehouse.gov/omb/inforeg/cipsea/cipsea_statute.pdf).

On March 7, 2008, the Office of Management and Budget released Statistical Policy Directive No. 4: Release and Dissemination of Statistical Products Produced by Federal Statistical Agencies: (http://www.whitehouse.gov/omb/fedreg/2008/030708_directive-4.pdf).

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