Table B-18. Estimated Measures of Reliability for Shipment Characteristics of Temperature Controlled Shipments (1) by Distance Shipped for the United States: 2012
(Estimates are based on data from the 2012 Commodity Flow Survey)
Distance shipped (2)
(based on Great Circle Distance)
|Coefficient of||Standard error of percent of total||Coefficient of||Standard error of percent of total||Coefficient of||Standard error of percent of total|
|variation of number||variation of number||variation of number|
|Less than 50 miles||4.5||0.6||4.2||1.3||4.8||0.2|
|50 to 99 miles||8.3||0.8||4.4||0.5||4.4||0.1|
|100 to 249 miles||3.1||0.5||3.7||0.5||3.9||0.4|
|250 to 499 miles||3.9||0.6||2.5||0.4||4.1||0.7|
|500 to 749 miles||3.8||0.2||6.8||0.3||6.1||0.7|
|750 to 999 miles||4.8||0.2||6.5||0.2||6.2||0.7|
|1,000 to 1,499 miles||4.8||0.2||4.7||0.2||5.4||0.9|
|1,500 to 1,999 miles||6.6||0.2||6.9||0.1||7.4||0.7|
|2,000 miles or more||6.5||0.1||5.4||0.1||5.3||0.6|
(1) Shipments that are temperature controlled are transported in a vehicle or container that regulates or maintains the temperature when en route to its destination.
(2) 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.
(3) 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.