Table B-17. Estimated Measures of Reliability for Hazardous Material Shipment Characteristics for Selected NAICS (1) Codes for the United States: 2012
(Estimates are based on data from the 2012 Commodity Flow Survey)
|NAICS code||NAICS title||Value||Tons||Ton-miles (2)||
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|
|324||Petroleum and coal products manufacturing||4.6||1.4||4.7||1.5||14.4||3.4||6.7|
|424||Merchant wholesalers, nondurable goods||4.6||1.4||5.5||1.5||10.5||1.7||12.6|
|4246||Chemical and allied products merchant wholesalers||10.6||0.2||12.7||0.3||10.9||0.3||11.1|
|4247||Petroleum and petroleum products merchant wholesalers||5.1||1.6||5.9||1.6||10.5||1.2||15.0|
|4931||Warehousing and storage||31.1||0.7||34.3||0.6||21.3||0.3||21.5|
(1) NAICS codes shown are those covered in the Commodity Flow Survey.
(2) 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>.
NAICS codes shown had the highest estimated weight without considering sampling variability and are shown in descending order.
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.