US Table 2e,,, "Shipment Characteristics by Total Modal Activity for the United States: Percent of Total for 2002, 1997, and 1993 ",,, "[Estimates are based on data from the 2002, 1997, and 1993 Commodity Flow Surveys. Because of rounding, estimates may not be additive] ",,, Mode of transportation (1) ,Ton-miles (2) (percent),, ,2002,1997,1993 Total,100.0,100.0,100.0 Truck,40.2,38.7,36.4 Rail,43.4,43.0,41.5 Shallow draft,8.2,8.5,10.5 Great Lakes,1.6,1.5,1.4 Deep draft,2.4,2.7,3.6 Air,0.2,0.2,0.2 "Parcel, U.S.P.S. or courier",0.6,0.6,0.5 Pipeline (3),S,S,S Other and unknown modes,1.4,2.8,3.8 "KEY: — Represents data cell equal to zero or less than 1 unit of measure. S Estimate does not meet publication standards because of high sampling variability or poor response quality.",,, "(1) Estimates represent activity for a given mode across single and multiple mode shipments. For example, ""Truck"" ton–miles includes total ton–miles for shipments moving only by truck plus ton–miles for truck segments of multiple mode shipments. (2) Ton–miles estimates are based on estimated distances traveled along a modeled transportation network. See ""Mileage Calculations"" section for additional information. (3) Estimates exclude shipments of crude petroleum (SCTG 16).",,, " NOTES: The Introduction and appendixes give information on confidentiality protection, sampling error, nonsampling error, sample design, and definitions. Links to this information on the Internet may be found at www.census.gov/cfs. Coverage for the 2002 Commodity Flow Survey (CFS) differs from the previous surveys due to a change from the 1987 Standard Industrial Classification System to the 1997 North American Industry Classification System and other survey improvements. Therefore, data users are urged to use caution when comparing 2002 CFS estimates with estimates from prior years.",,, "SOURCE: Bureau of Transportation Statistics (USDOT) and U.S. Census Bureau, 2002 Commodity Flow Survey, United States Data, December 2004.",,, ,,, ,,, ,,, ,,,