The Commodity Flow Survey (CFS) is conducted every 5 years by the Bureau of Transportation Statistics (BTS) in partnership with the U.S. Census Bureau as part of the Economic Census. The CFS provides data for most of the U.S. economy on commodities shipped, their value and weight, mode of transport, and origin and destination within and between all U.S. regions. The survey covers about 75 percent of the tonnage shipped from a domestic origin to a domestic destination.

The CFS is the foundation for the Freight Analysis Framework (FAF), a freight database produced through a partnership between BTS and the Federal Highway Administration (FHWA). The FAF incorporates domestic shipments measured in the CFS (covering mining, manufacturing, wholesale, and other selected industries). It augments the CFS data with foreign trade statistics from Census, agricultural data from the Department of Agriculture, energy commodity data from the Department of Energy, and other sources.

The fourth generation of FAF (FAF4) is based on the 2012 CFS, which includes improvements to data collection, data editing, and an expanded number of geographic areas. Improvements were also made to the non-CFS components of FAF.

FAF provides tonnage and value estimates by commodity type, mode, origin, and destination for years the CFS is conducted, provides annual estimates for years in between the CFS, and long-range (30 year) forecasts in 5-year increments. It also includes an assignment of truck flows to the highway network for the CFS year and a 30-year forecast to provide a picture of freight truck volumes.

FAF forecasts are based on long-term U.S. economic projections, including real gross domestic product growth, nonfarm business productivity, real oil prices, and the Federal budget deficit. Detailed information on CFS data and methodologies are available at www. bts.gov/publications/commodity_flow_survey. Information on FAF data and methodologies are available at www.ops.fhwa.dot.gov/freight/ freight_analysis/faf/index.htm. It is important to note that while the FAF is more complete in coverage of freight flows, the CFS provides greater commodity detail and additional shipment characteristics, such as hazardous materials class.

It is important to note that the input sources for the FAF4 base year of 2012 are final, but each updated version of FAF incorporates continuous improvements to data quality. As a result, the latest data available online may not precisely match the data in this chapter.