Table B-2b. Estimated Measures of Reliability for Shipment Characteristics by Total Modal Activity for the United States: 2012 and 2007
(Estimates are based on data from the 2012 and 2007 Commodity Flow Surveys)
Mode of transportation (1) | Ton-miles (2) | Average miles per shipment | ||||
---|---|---|---|---|---|---|
Coefficient of variation of number | Standard error of percent change | Coefficient of variation of number | Standard error of percent change | |||
2012 | 2007 | 2012 | 2007 | |||
Total | 3.7 | 3.6 | 4.5 | 3.2 | 2.5 | 4.1 |
Truck (3) | 1.6 | 1.4 | 1.9 | 4.1 | 4.4 | 6.6 |
Rail | 8.1 | 7.7 | 10.0 | 3.6 | 4.6 | 6.0 |
Inland water | 14.6 | 10 | 13.8 | 15.2 | 9.9 | 28.5 |
Great Lakes | 26.1 | 27.9 | 39.5 | 13.7 | 9.2 | 16.0 |
Deep sea | 23.7 | 17.1 | 20.7 | 7.5 | 6.9 | 9.1 |
Air | 15 | 9.6 | 16.5 | 13.4 | 2.5 | 10.0 |
Pipeline (4) | S | S | S | S | S | S |
Parcel, U.S. Postal Service, or courier | 2.5 | 3 | 3.2 | 2.7 | 2.3 | 3.3 |
Other modes | 22.7 | 9.3 | 0.2 | S | 12.7 | S |
KEY: S = Withheld because estimate did not meet publication standards.
(1) Estimates represent activity for a given mode across single and multiple mode shipments. For example, “Truck” ton-miles includes total ton-miles for shipments moving only by truck plus ton-miles for truck segments of multiple mode shipments.
(2) Ton-miles estimates are based on estimated distances traveled along a modeled transportation network. See “Mileage Calculations” section for additional information.
(3) “Truck” as a single mode includes shipments that were made by only private truck or only for-hire truck.
(4) Estimates for pipeline exclude shipments of crude petroleum (SCTG 16).
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.