Table B-2a. Estimated Measures of Reliability for Hazardous Material Shipment Characteristics by Hazard Class for the United States: 2012
(Estimates are based on data from the 2012 Commodity Flow Survey)
|Hazard class and description||Value||Tons||Ton-miles (1)||Average miles per shipment— coefficient of variation of number|
|Coefficient of variation of number||Standard error of percent of total||Coefficient of variation of number||Standard error of percent of total||Coefficient of variation of number||Standard error of percent of total|
|Class 1, Explosives||17.6||0.2||21.7||Z||13.5||0.1||3.7|
|Class 2, Gases||5.6||0.3||4.9||0.4||9.9||0.9||10.0|
|Class 3, Flammable and combustible liquid||3.6||0.6||4.1||0.4||8.1||1.5||9.3|
|Class 4, Flammable solid; spontaneously combustible material; dangerous when wet material||14.2||Z||13.7||0.1||28.5||0.5||24.7|
|Class 5, Oxidizers and organic peroxides||9.3||Z||10.3||0.1||17.5||0.4||11.5|
|Class 6, Toxic materials and infectious substances||14.6||0.1||28.4||0.1||23.3||0.2||10.2|
|Class 7, Radioactive material||34.5||0.2||S||S||35.7||Z||36.3|
|Class 8, Corrosive material||6.3||0.2||8.0||0.4||9.1||1.0||14.0|
|Class 9, Miscellaneous hazardous material||9.4||0.2||17.2||0.3||12.7||0.9||19.4|
KEY: S = Withheld because estimate did not meet publication standards.
Z = Rounds to zero.
(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>.
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.