NOTE: This map is based on
information from the Commodity Flow Survey (CFS). Because the CFS data are
drawn from a survey, the data used in this map are subject to sampling errors
that could affect the estimates of shipment size and the relative positions of
the states. See appendix table 1-20 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.
