Table B-1a. Estimated Measures of Reliability for Shipment Characteristics by Mode of Transportation for the United States: 2012
(Estimates are based on data from the 2012 Commodity Flow Survey)
|Mode of transportation||Value||Tons||Ton-miles (1)||
Average miles per shipment
coefficient of variation of number
|Coefficient of variation of number||Standard error of percent of total||Coefficient of variation of number||Standard error of percent of total||Coefficient of variation of number||Standard error of percent of total|
|Air (includes truck and air)||4.5||0.1||7.2||Z||13.4||Z||8.8|
|Parcel, U.S. Postal Service, or courier||1.4||0.2||3.0||Z||2.6||Z||2.6|
|Truck and rail||5.5||0.1||7.2||0.1||5.7||0.4||6.0|
|Truck and water||15.4||Z||22.7||0.1||38.5||0.7||7.3|
|Rail and water||13.0||Z||20.1||0.1||26.2||0.3||25.6|
|Other multiple modes||33.3||Z||36.6||Z||32.2||Z||S|
KEY: S = Withheld because estimate did not meet publication standards.
Z = Rounds to zero.
(1) Ton-miles estimates are based on estimated distances traveled along a modeled transportation network. See “Mileage Calculations” section for additional information.
(2) “Truck” as a single mode includes shipments that were made by only private truck or only for-hire truck.
(3) 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.