NOTE: This map is based on information from the Commodity Flow Survey (CFS). Because the CFS data used in this map are drawn from a survey, they are subject to sampling errors that could affect the estimates of shipment size and the relative positions of the states. See appendix table 1-18 for a list showing the rest of the states. Information on measures of sampling variability for the data used in the map is available at http://www.bts.gov/.
SOURCE: U.S. Department of Transportation, Research and Innovative Technology Administration, Bureau of Transportation Statistics, 2002 Commodity Flow Survey data, April 2005.