Estimates are based on data from the 2007 and 2002 Commodity Flow Surveys. Because of rounding, estimates may not be additive.
|Description||Value (percent)||Tons (percent)||Ton-miles (percent) 1||Value Standard Error of %||Tons Standard Error of %||Ton-miles Standard Error of %|
|Packing Group I||27||26.9||26.2||26.3||22.3||24.5||0.9||0.9||1.2||1||1.7||2.1|
KEY: - = Zero or Less than half the unit shown; thus, it has been rounded to zero.
1 Ton-miles estimates are based on estimated distances traveled along a modeled transportation network.
NOTES: Packing Groups I, II, and III reflect the level of hazard associated with the material being shipped. Packing Group I is the most rigorous. Value-of-shipment estimates are reported in current prices. More information on sampling error, confidentiality protection, nonsampling error, sample design, and definitions may be found at http://www.bts.gov/publications/commodity_flow_survey/.
SOURCE: U.S. Department of Transportation, Research and Innovative Technology Administration, Bureau of Transportation Statistics and U.S. Department of Commerce, U.S. Census Bureau, 2007 Economic Census: Transportation Commodity Flow Survey, December 2009.