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 | 14.0 | – | 9.5 |
Truck | 7.8 | 5.6 | 8.3 |
Rail | 15.5 | 4.8 | 7.7 |
Shallow draft | S | S | 29.8 |
Great Lakes | S | S | 31.6 |
Deep draft | S | S | 38.6 |
Air | 37.8 | – | 9.0 |
Parcel, USPS or courier | S | S | 31.6 |
Pipeline | S | S | S |
Other and unknown modes | 30.2 | 0.8 | S |
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.