Data Gaps

Data Gaps

In the future, there will be data gaps in several areas of transportation due to continuing resource constraints. Federal agencies have reduced in scope, postponed, delayed and in some cases discontinued several long term data series important to understanding changes in the field of transportation. The Bureau of Transportation Statistics (BTS), for example, has not undertaken a previously planned long distance travel survey in 2007 due to resource constraints. This survey was conducted most recently in 2001/2002 as part of the National Household Travel Survey (NHTS) conducted jointly by BTS and the Federal Highway Administration (FHWA), in 1995 as the standalone American Travel Survey, and in 1977 by the U.S. Census Bureau. These long distance travel surveys provided data on the number, length, origins and destinations, modes of transportation, purpose, and traveler characteristics of U.S. residents making long-distance trips.

Also, due to resource constraints, the Census Bureau is not undertaking the previously planned repeat of the Vehicle Inventory and Use Survey (VIUS) as part of the 2007 Economic Census. The VIUS is the most indepth inventory of the characteristics of the nation's highway truck fleet, covering all categories from lightweight pickups and utility vehicles through large trucks. Previous editions of this survey, and its earlier counterpart, the Truck Inventory and Use Survey, were conducted at twice a decade intervals as part of the Economic Census extending back to 1963.

In addition, the U.S. Army Corps of Engineers (USACE) has discontinued one of its international maritime statistics data sets—the U.S. foreign trade-based data series. Updated preliminary and monthly cargo summary reports are no longer available on the Navigation Data Center and U.S. Department of Transportation, Maritime Administration web sites (type of service, dollar value, weight) and the monthly and annual waterborne databanks were discontinued. Monthly foreign trade and transportation data will no longer be publicly available from the USACE.

Transportation data needs continue to be discussed by the transportation community. The Transportation Research Board (TRB), part of the National Academy of Sciences, has sought input from its numerous committees of transportation experts and officials to identify key needs. Two circulars have resulted from this process to date.[1] The first, issued in December 2006, suggested that TRB committees annually review data needs, priorities, and costs. The second, issued in August 2007, details the results of discussions by State transportation officials.

The discussion focused on actions to ensure availability of data for effective transportation decision-making and opportunities for national efforts to advance transportation data systems. A summary of the findings is shown in box B.

The Bureau of Transportation Statistics, in partnership with the U.S. Census Bureau, is conducting the 2007 Commodity Flow Survey (CFS). As a result of meetings and other consultations with stakeholders, BTS worked with Census to improve coverage of the CFS, publish industry data for the first time, and improve geography. The 2007 CFS data collection is nearly complete. BTS and Census work jointly to evaluate and monitor the progress of this effort and monitor overall data quality.

The FHWA in cooperation with its modal partners, including BTS, produced the Freight Analysis Framework, version 2, (FAF2). The 2002 CFS data form the basis of FAF2. The FAF integrates data from a variety of sources to estimate commodity flows and related freight transportation activity among states, regions, and major international gateways. The original version, FAF1, provided estimates for 1998 and forecasts for 2010 and 2020. The new version, FAF2, provides estimates for 2002, annual provisional estimates beginning with 2005, and forecasts through 2035. All of the products listed here are available at

1 Transportation Research Board, Data and Information Systems Section, Transportation Research Circular E-C109: Transportation Information Assets and Impacts (Washington, DC: Transportation Research Board of the National Academy of Sciences) December 2006, and Transportation Research Board Circular, E-C121, Information Assets to Support Transportation Decision-Making (Washington, DC: TRB of the NAS), August 2007.