Value
Tons
Ton-miles3
1 Includes air, parcel, postal, courier, other, and unknown.
2 Excludes most shipments of crude oil.
3 Pipeline data are not published because of high sampling variability or other reasons.
NOTE: Percentages may not add to 100 due to rounding
SOURCE: U.S. Department of Commerce, Census Bureau, 1997 Economic Census1997 Commodity Flow Survey, Hazardous Materials (Washington, DC: December 1999), table 1.