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) |
Value | Tons | Ton-miles (2) | ||||||
|---|---|---|---|---|---|---|---|---|---|
| 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 | ||||
| 2012 | 2007 | 2012 | 2007 | 2012 | 2007 | ||||
| Total | 1.1 | 0.8 | 1.6 | 1.8 | 1.6 | 2.2 | 3.7 | 3.6 | 4.5 |
| 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.