Estimates are based on preliminary data from the 2012 Commodity Flow Survey. Because of rounding, estimates may not be additive
|Mode of transportation (1)||
2012 Ton–miles (2)
|Ton-miles (Percent of Total)||2012 Average miles per shipment||Ton-miles CV (3)||Standard Error for Ton-miles (Percent of Total)||Average miles per shipment CV|
|Parcel, U.S.P.S. or courier||20,438||0.6||873||2.0||Z||1.5|
S - Estimate does not meet publication standards because of high sampling variability or poor response quality.
Z - Less than half the unit shown. For the 2012 CFS, represents an estimate that is between zero and half the unit shown, thus, has rounded down to zero.
(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.
(3) Coefficient of Variation.
(4) Estimates exclude shipments of crude petroleum.
NOTE: These data are preliminary and are subject to change; they will be superseded by data released in later reports. Value-of-shipment estimates have not been adjusted for price changes. Estimated measures of sampling variability for each estimate known as coefficients of variation (CV) are also provided in these tables.
More information on sampling error, confidentiality protection, nonsampling error, sample design, and definitions may be found at http://www.rita.dot.gov/bts/sites/rita.dot.gov.bts/files/publications/co....
SOURCE: U.S. Department of Transportation, Research and Innovative Technology Administration, Bureau of Transportation Statistics and U.S. Department of Commerce, U.S. Census Bureau, 2012 Economic Census: Transportation Commodity Flow Survey, Preliminary Release, December 2013.