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) |
Value — standard error |
Tons — standard error |
Ton-miles (2) — standard error |
|||
|---|---|---|---|---|---|---|
| 2012 | 2007 | 2012 | 2007 | 2012 | 2007 | |
| Total | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 |
| 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.