|Mode of Transportation||1993||1997||2002|
|Combined total (CFS plus out-of-scope estimates)||100.0||100.0||100.0||100.0||100.0||100.0||100.0||100.0||100.0|
|Air (includes truck and air)||5.5||0.1||0.2||7.7||0.1||0.4||7.4||0.1||0.3|
|Multimodal combinations (1)||9.2||1.7||4.6||11.0||1.5||5.4||10.6||1.3||5.0|
|Other and unknown modes||3.4||4.0||2.5||3.6||3.0||1.9||3.6||3.2||1.7|
(1) Multimodal includes the traditional intermodal combination of truck and rail plus truck and water; rail and water; parcel, postal, and courier service; and other multiple modes for the same shipment.
NOTE: The data in this table include estimates of out-of-scope missing pieces from the Bureau of Transportation Statistics. These estimates cover logging, farm-based truck shipments, truck imports from Canada and Mexico, rail imports from Canada and Mexico, air cargo imports and exports, water imports and exports, and pipeline crude and petroleum products shipments. The estimates exclude non-commercial freight shipments such as government shipments and municipal solid waste.
SOURCE: U.S. Department of Transportation, Bureau of Transportation Statistics, based on 1993, 1997, and 2002 Commodity Flow Survey data plus additional estimates from Bureau of Transportation Statistics.