The CFS is the foundation for the FAF. The 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 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 three-fourths of the tonnage shipped from a domestic origin to a domestic destination.

The FAF supplements CFS data with a variety of other sources to estimate total tonnage and value, commodity type, mode, origin, and destination for 1997, 2002, 2007, 2011, and 2040. It also assigns truck flows to the highway network for 2007 and 2040 to provide a picture of freight truck volumes.

While the FAF is more complete, the CFS provides greater commodity detail and additional shipment characteristics, such as hazardous materials class. The most recently published CFS data covers 2007, while earlier surveys cover 1993, 1997, and 2002. The 2012 CFS data are being processed as this report goes to press.

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.