Table B-2a. Estimated Measures of Reliability for Shipment Characteristics by Total Modal Activity for the United States: 2002
Monday, July 2, 2012
Table B-2a. Estimated Measures of Reliability for Shipment Characteristics by Total Modal Activity for the United States: 2002
[Estimates are shown as percents and are based on data from the 2002 Commodity Flow Survey]
| Mode of transportation | Ton-miles | CV of Average miles per shipment | |
|---|---|---|---|
| CV | Std. error of percent | ||
| Total | 3.7 | – | 2.8 |
| Truck | 2.8 | 1.5 | 3.6 |
| Rail | 7.6 | 1.6 | 6.1 |
| Shallow draft | 9.4 | 0.6 | 13.1 |
| Great Lakes | 18.1 | 0.3 | 16.0 |
| Deep draft | 17.3 | 0.4 | 11.1 |
| Air | 15.7 | – | 4.3 |
| Parcel, U.S.P.S. or courier | 4.2 | – | 2.3 |
| Pipeline | S | S | S |
| Other and unknown modes | 9.7 | 0.2 | 13.0 |
KEY:
– Represents data cell equal to zero or less than 1 unit of measure.
S Estimate does not meet publication standards because of high sampling variability or poor response quality.
CV Coefficient of variation of number.
NOTE: 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: Bureau of Transportation Statistics (USDOT) and U.S. Census Bureau, 2002 Commodity Flow Survey, United States Data, December 2004.