Estimates are based on preliminary data from the 2007 Commodity Flow Survey. Because of rounding, estimates may not be additive
(Based on Great Circle Distance)
|Value CV (3)||Tons CV||Ton-miles CV|
|Less than 50 miles||3,909,625||7,087,855||157,308||1.5||1.4||1.3|
|50 - 99 miles||1,084,779||1,288,812||129,358||1.4||4.1||5.9|
|100 - 249 miles||1,832,167||1,780,263||415,260||1.4||7.4||7.2|
|250 - 499 miles||1,642,995||1,112,023||554,553||1.8||3.9||3.8|
|500 - 749 miles||1,047,504||665,131||577,798||2.2||5.4||5.3|
|750 - 999 miles||741,766||514,753||618,350||3.1||7.6||8.0|
|1,000 - 1,499 miles||728,986||410,497||648,167||3.7||7.9||7.6|
|1,500 - 2,000 miles||454,626||95,219||210,219||2.5||3.5||3.7|
|More than 2,000 miles||389,055||62,058||179,794||3.4||7.1||6.7|
(1) Shipments are grouped into distance categories based on Great Circle Distance (GCD). GCD is the shortest distance between 2 points on the surface of a sphere over the surface of that sphere.
(2) Ton-miles estimates are based on estimated distances traveled along a modeled transportation network.
(3) Coefficient of Variation.
NOTES: 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and are subject to change; they will be superseded by data released in later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.census.gov/cfs.
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, 2007 Economic Census: Transportation Commodity Flow Survey, Preliminary Release, December 2008.