Table B-3a. Estimated Measures of Reliability for Shipment Characteristics by Distance Shipped for the United States: 2012
(Estimates are based on data from the 2012 Commodity Flow Survey)
|
Distance shipped (1) (based on Great Circle Distance) |
Value | Tons | Ton-miles (2) | |||
|---|---|---|---|---|---|---|
|
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 | |
| Total | 1.1 | 0.0 | 1.8 | 0.0 | 3.7 | 0.0 |
| Less than 50 miles | 2.0 | 0.5 | 2.2 | 0.7 | 2.4 | 0.2 |
| 50 to 99 miles | 2.2 | 0.2 | 2.8 | 0.3 | 3.1 | 0.2 |
| 100 to 249 miles | 1.8 | 0.2 | 3.2 | 0.3 | 3.6 | 0.4 |
| 250 to 499 miles | 1.2 | 0.2 | 4.1 | 0.3 | 4.0 | 0.5 |
| 500 to 749 miles | 1.7 | 0.2 | 4.4 | 0.2 | 4.9 | 0.5 |
| 750 to 999 miles | 1.9 | 0.2 | 8.4 | 0.3 | 8.3 | 1.0 |
| 1,000 to 1,499 miles | 2.5 | 0.1 | 6.9 | 0.2 | 6.8 | 0.7 |
| 1,500 to 1,999 miles | 4.0 | 0.1 | 5.4 | Z | 7.4 | 0.7 |
| 2,000 miles or more | 3.5 | 0.1 | 4.3 | Z | 4.2 | 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.