Short Line Rail: Its Role in Intermodalism and Distribution

completeness. Regardless of the measures chosen, what is clear is that freight traffic
has grown enormously over the years, and more importantly, trucks have become the
primary mover of freight nationally.
The ton-mile metric is the primary physical measure of freight transportation output, as it
addresses both weight and distances covered in freight handling. As Dennis (2007)
states, national estimates of ton-miles have been developed by various organizations
over the years. These estimates have differed in coverage and reliability. The U.S.
Bureau of Transportation Statistics (BTS) has worked to improve basic measures of
transportation activity, including ton-miles. Various BTS estimates for air, truck, rail,
water, and pipelines are used for the following tables. 1
Table 4.1 clearly shows the overall increase in the ton-miles of freight traffic in the
United States post-war. This increase parallels the growth in population and the
economy during that period. What is also clear is the dramatic increase in both truck
and air freight. The former corresponding to the development of the Interstate Highway
System, beginning in 1955. The latter corresponding to changes in the underlying
economy of the Unites States as it shifted more into a service-based economy and
away from an agricultural and extractive industry economy. Also evident is the increase
and then decrease in the roles that both domestic water and pipeline transportation
have played in the movement of freight and commodities. However, ton-mile data do
not portray clearly the dramatic shifts that have occurred over that period of time with
regard to modal share.
Table 4.1: U.S. Ton-Miles of Freight – 1960 – 2006
(Millions)
1960 1970 1980 1990 1995 2000 2005 2006
TOTAL U.S. ton-miles of freight
U 2,206,713 3,404,015 3,621,943 4,104,235 4,328,642 4,574,701 4,637,513
Air 553 2,709 4,840 10,420 12,720 15,810 15,741 15,357
Truck 285,000 412,000 629,675 848,779 1,034,041 1,192,825 1,291,515 1,294,492
Railroad 572,309 764,809 932,000 1,064,408 1,317,010 1,546,319 1,733,777 1,852,833
Domestic water transportation U
596,195 921,835 833,544 807,728 645,799 591,276 561,629
Pipeline 229.000 431,000 915,666 864,792 932,737 927,889 942,392 913,202
Oil & Oil Products U U 588,000 584,100 601,100 577,000 607,500 584,700
Natural Gas U U 327,666 280,692 331,637 350,889 334,892 328,502
NOTES: BTS is developing more comprehensive and reliable estimates of ton-miles for the air, truck, rail, water, and pipeline modes
than are presented in table 1-46a. These improved estimates are not comparable to data in table 1-46a. Improved estimates for
1960-1989, which will allow more comprehensive and reliable data for the entire period from 1960 to present, are still under
development and will be reported when they are completed.
Numbers may not add to totals due to rounding.
SOURCE: U.S. Department of Transportation, Bureau of Transportation Statistics, special tabulation.
While not providing an historical picture of the change in modal share of freight handled
in the U.S., Table 4.2 does dramatically illustrate the role trucking plays in the
1 Fuller coverage is achieved by combining reported data from established sources, estimates from surveys, and calculations based
on certain assumptions. For more information on the improved approach, including discussion of data sources and methods used,
visit the BTS web site at www.bts.gov, and use the search engine to find improved estimates of ton-miles.
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