Table B-3c. Estimated Standard Errors for Shipment Characteristics by Distance Shipped for the United States: Percentage of Total for 2012 and 2007
(Estimates are based on data from the 2012 and 2007 Commodity Flow Surveys)
Distance shipped (1)
(based on Great Circle Distance)
|Less than 50 miles||0.5||0.4||0.7||0.7||0.2||0.2|
|50 to 99 miles||0.2||0.1||0.3||0.4||0.2||0.2|
|100 to 249 miles||0.2||0.2||0.3||0.4||0.4||0.6|
|250 to 499 miles||0.2||0.2||0.3||0.3||0.5||0.7|
|500 to 749 miles||0.2||0.1||0.2||0.1||0.5||0.4|
|750 to 999 miles||0.2||0.1||0.3||0.3||1.0||1.1|
|1,000 to 1,499 miles||0.1||0.1||0.2||0.2||0.7||0.9|
|1,500 to 1,999 miles||0.1||0.2||Z||0.0||0.7||0.3|
|2,000 miles or more||0.1||0.2||Z||0.0||0.3||0.3|
KEY: Z = Rounds to zero.
(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.