"Table 1-56:  U.S. Hazardous Materials Shipments by Transportation Mode, 1997",,,,,,,,
,Value,,Tons,,Ton-miles,,,
Transportation mode ,($ billion),Percent,(millions),Percent,(billions),Percent,,
TOTAL all modes,466.4,100.0,"1,565.2",100.0,263.8,100.0,,
"Single modes, total",452.7,97.1,"1,541.7",98.5,258.9,98.1,,
Trucka,298.2,63.9,869.8,55.6,74.9,28.4,,
For-hire,134.3,28.8,336.4,21.5,45.2,17.1,,
Privateb,160.7,34.5,522.7,33.4,28.8,10.9,,
Rail,33.3,7.1,96.6,6.2,74.7,28.3,,
Water,27.0,5.8,143.2,9.1,68.2,25.9,,
Air,8.6,1.8,0.1,–,0.1,–,,
Pipelinec,85.7,18.4,432.1,27.6,S,S,,
"Multiple modes, total",5.7,1.2,6.0,0.4,3.1,1.2,,
"Parcel, U.S. Postal Service or Courier",2.9,0.6,0.1,–,0.1,–,,
Other,2.9,0.6,5.9,0.4,3.0,1.1,,
"Unknown and other modes, total",7.9,1.7,17.5,1.1,1.8,0.7,,
KEY:  – = less than 1 unit of measure or equal to zero; S = data are not published because of high sampling variability or other reasons. ,,,,
"a Truck as a single mode includes shipments that went by private truck only, for-hire truck only, or a combination of both.",,,,
b Private truck refers to a truck operated by a temporary or permanent employee of an establishment or the buyer/receiver of the shipment.,,,,
c Excludes most shipments of crude oil.  See previous table for the estimated amount of crude oil and petroleum products transported in the United States.,,,,
NOTE,,,,
Numbers may not add to totals due to roundings.,,,,
SOURCE,,,,
"U.S. Department of Transportation, Bureau of Transportation Statistics,  U.S. Department of Commerce, Census Bureau, 1997 Economic Census, Transportation, 1997 Commodity Flow Survey, Hazardous Materials (Washington, DC: December 1999), table 1.",,,,
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