Table B-15b. Estimated Standard Errors for Hazardous Material Shipment Characteristics for Packing Group I for the United States: Percentage of Total for 2012 and 2007
(Estimates are based on data from the 2012 and 2007 Commodity Flow Surveys)
|Ton-miles (1) —standard error|
|Packing Group I||0.9||0.9||1.1||1.2||1.8||1.7|
(1) Ton-miles estimates are based on estimated distances traveled along a modeled transportation network. See “Mileage Calculations” section for additional information.
NOTES: The Introduction and appendixes give information on confidentiality protection, sampling error, nonsampling error, sample design and definitions. Links to this information on the Internet may be found at <www.census.gov/econ/cfs>.
Packing Groups I, II, and III reflect the level of hazard associated with the material being shipped. Packing Group I is the most rigorous.
SOURCE: U.S. Department of Transportation, Bureau of Transportation Statistics and U.S. Department of Commerce, U.S. Census Bureau, 2012 Economic Census: Transportation Commodity Flow Survey, December 2014.