Table B-2. Estimated Measures of Reliability for Shipment Characteristics by Total Modal Activity for State of Origin: 2002
Table B-2. Estimated Measures of Reliability for Shipment Characteristics by Total Modal Activity for State of Origin: 2002
[Estimates are based on data from the Commodity Flow Survey. Because of rounding, estimates may not be additive]
Mode of transportation | Ton-miles | CV of average miles per shipment |
|
---|---|---|---|
CV | Std. error of percent | ||
Total | 8.0 | – | 11.9 |
Truck | 22.1 | 4.3 | 31.8 |
Rail | 19.6 | 3.1 | 8.4 |
Shallow draft | 20.3 | 4.8 | 26.5 |
Great Lakes | 31.1 | 1.6 | 21.1 |
Deep draft | S | S | 31.6 |
Air | 15.4 | – | 3.6 |
Parcel, USPS or courier | S | S | 31.6 |
Pipeline | S | S | S |
Other and unknown modes | 32.7 | 0.5 | 38.3 |
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 onf 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, Individual State Data, December 2004.