NOTE: The value of freight shipments is inflation-adjusted with the goods
GDP deflator in chained 2000 dollars.
The data in this figure include the Bureau of Transportation Statistics
estimates of out-of-scope missing pieces. See notes on table 1 for additional
information on the BTS estimates.
SOURCE: U.S. Department of Transportation, Bureau of Transportation Statistics,
based on 1993, 1997, and preliminary 2002 Commodity Flow Survey data plus additional estimates
from Bureau of Transportation Statistics.