Table B-19. Estimated Measures of Reliability for Shipment Characteristics of Temperature Controlled Shipments (1) by Shipment Weight for the United States: 2012
(Estimates are based on data from the 2012 Commodity Flow Survey)
| Shipment weight | Value | Tons | Ton-miles (2) | Average miles per shipment | |||
|---|---|---|---|---|---|---|---|
| Coefficient of | Standard error of percent of total | Coefficient of | Standard error of percent of total | Coefficient of | Standard error of percent of total | coefficient of | |
| variation of number | variation of number | variation of number | variation of number | ||||
| Total | 3.2 | 0 | 2.3 | 0 | 2.1 | 0 | 6 |
| Less than 50 lbs. | 8 | 0.5 | 8.4 | Z | 12.6 | Z | 10.6 |
| 50 to 99 lbs. | 13.6 | 0.3 | 10.1 | Z | 15.2 | Z | 14 |
| 100 to 499 lbs. | 6.8 | 0.5 | 5.7 | 0.1 | 6.1 | Z | 6.7 |
| 500 to 749 lbs. | 7.9 | 0.2 | 3.6 | 0.1 | 4.7 | Z | 3.5 |
| 750 to 999 lbs. | 6.5 | 0.1 | 2.5 | Z | 3.4 | Z | 3.4 |
| 1,000 to 9,999 lbs. | 5.4 | 0.8 | 4 | 0.7 | 3.2 | 0.4 | 3 |
| 10,000 to 49,999 lbs. | 2.5 | 1 | 2.3 | 1.1 | 2.6 | 0.9 | 2.6 |
| 50,000 to 99,999 lbs. | 15.8 | 0.4 | 14.5 | 1.3 | 12.2 | 0.5 | 9.7 |
| 100,000 lbs. or more | 7.1 | 0.2 | 10.8 | 0.8 | 7.5 | 1.3 | 8.5 |
KEY: Z = Rounds to zero.
(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) 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.