Table 23,,,,,, Weight of U.S. International Merchandise Trade by Mode of Transportation: 2002,,,,,, "(Thousands of short tons) ",,,,,, ,Exportsa,"Modal %",Imports,"Modal %","Total tradea","Total modal %" Total,"477,075",100.0,"1,153,011",100.0,"1,630,087",100.0 Waterb,"349,835",73.3,"897,128",77.8,"1,246,963",76.5 Air,"2,549",0.5,"3,921",0.3,"6,470",0.4 Truck,"91,436",19.2,"96,344",8.4,"187,780",11.5 Rail,"24,858",5.2,"78,036",6.8,"102,894",6.3 Pipeline,"5,822",1.2,"74,826",6.5,"80,648",4.9 "Other, unknown, & miscellaneous","2,576",0.5,"2,757",0.2,"5,332",0.3 "a BTS estimated the export weight for truck, rail, pipeline, and other and unknown based on value-to-weight ratios from the import data. This was necessary, because export weights for surface modes are not currently reported. Weight for water and air exports and imports are from U.S. Department of Commerce, U.S. Census Bureau.",,,,,, "b The weight data for water transportation vary from those officially reported by the U.S. Army Corps of Engineers, because the data in this table exclude intransit shipments (merchandise shipped from one foreign country to another via a U.S. port but not part of U.S. official merchandise trade). BTS uses Census Bureau trade-based data to allow for a complete modal comparison among the different freight transportation modes.",,,,,, "Notes: Numbers may not add to totals due to rounding. Water—Excludes intransit data (merchandise shipped from one foreign country to another via a U.S. water port). Imports—Excludes imports valued at less than $1,250. Import value is based on U.S. general imports, customs value basis. Exports—Excludes exports valued at less than $2,500. Export value is FAS (free alongside ship) and represents the value of exports at the port of export, including the transaction price and inland freight, insurance, and other charges.",,,,,, "Sources: Compiled by U.S. Department of Transportation (USDOT), Bureau of Transportation Statistics (BTS), October 2003. Water and air data—U.S. Department of Commerce, U.S. Census Bureau, Foreign Trade Division, U.S. Exports of Merchandise, CD-ROM and U.S. Imports of Merchandise, CD-ROM, December 2002. Total, truck, rail, pipeline, other and unknown data—USDOT, BTS, Transborder Surface Freight Data 2003; and special calculation, October 2003.",,,,,, ,,,,,, ,,,,,, ,,,,,, ,,,,,, ,,,,,,