Table B-3b. Estimated Measures of Reliability for Shipment Characteristics by Distance Shipped for the United States: 2012 and 2007
(Estimates are based on data from the 2012 and 2007 Commodity Flow Surveys)
Distance shipped (1)
(based on Great Circle Distance)
|Coefficient of variation of number||Standard error of percent change||Coefficient of variation of number||Standard error of percent change||Coefficient of variation of number||Standard error of percent change|
|Less than 50 miles||2.0||1.4||3.2||2.2||2.1||2.7||2.4||2.6||2.8|
|50 to 99 miles||2.2||1.6||3.5||2.8||3.2||3.9||3.1||3.5||4.0|
|100 to 249 miles||1.8||1.3||2.6||3.2||3.2||3.8||3.6||4.3||4.5|
|250 to 499 miles||1.2||1.8||2.3||4.1||3.4||4.7||4.0||3.3||4.5|
|500 to 749 miles||1.7||1.6||2.6||4.4||3.5||5.4||4.9||3.6||5.9|
|750 to 999 miles||1.9||2.4||3.4||8.4||9.7||11.1||8.3||9.7||10.9|
|1,000 to 1,499 miles||2.5||2.3||3.7||6.9||7.6||9.4||6.8||7.4||9.1|
|1,500 to 1,999 miles||4.0||4.5||6.0||5.4||5.1||8.2||7.4||4.4||9.9|
|2,000 miles or more||3.5||4.7||6.0||4.3||5.6||5.8||4.2||6.8||6.1|
(1) Shipments are grouped into distance categories based on Great Circle Distance (GCD). GCD is the shortest distance between two points on the surface of a sphere over the surface of that sphere.
(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/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.