The Commodity Flow Survey shows that by 2002, gravel and crushed stone had replaced coal as the top commodity measured by weight, while the top commodities by value and ton-mile remained the same as in 1993.
The Freight Shipments by Commodity table presents the value, weight, and ton-miles as well as the relative shares of the major commodities shipped by U.S. businesses. The commodities are based on the two-digit Standard Classification of Transported Goods (SCTG) coding system. Because the Commodity Flow Survey (CFS) does not cover several important commodities and sectors of the economy, such as crude petroleum pipeline movements and imports, the volumes and shares of the commodities moved could vary with the addition of out-of-scope shipments. While BTS has aggregate estimates of the major missing pieces such as imports, crude petroleum, logging, and some of the in-scope sectors that are underrepresented in the CFS, further extensive analysis is needed to disaggregate these data into appropriate two-digit commodity groups. BTS intends to research this as part of the ongoing CFS data analysis.