Class I railroads1 provide vital freight transportation services—carrying more than one-third of domestic freight ton-miles2 each year . In order to provide efficient and timely services, these companies maintained nearly 170,000 miles of track in 2001, down from nearly 200,000 miles in 1991 . Class I track mileage has been declining for many decades especially on lower density lines, in part because ownership and maintenance is expensive. As such, rail companies have focused more on replacing worn rails and crossties than on laying new track.
Throughout the 1990s, rail companies replaced an average of 743,000 tons of rail each year (figure 54). The yearly replacements, which can vary substantially because of the long life of rails, ranged from a high of 875,000 tons in 1992 to a low of 643,000 tons in 1997. Using the most common rail weight (130 to 139 lbs per yard), it would take approximately 120 tons of rail to cover one mile .
There was some growth in the amount of new rails added to the Class I system in the late 1990s as firms increased capacity to handle growing amounts of coal traffic and reconfigured their systems as a result of mergers. Over 200,000 tons of new rail were added both in 1998 and 1999, up from 19,000 in 1990.
Railroads also replace crossties periodically in order to ensure the integrity of their tracks. Throughout the 1990s, railroads replaced an average of 12.2 million crossties each year (figure 55). The yearly replacements ranged from a high of 14.1 million crossties in 1990 to a low of 10.4 million in 1998. There was some growth in the number of new crossties added to the Class I system in the late 1990s as firms increased capacity or reconfigured their systems. In 1998, 1.8 million new crossties were added; but by 2001, the number of new crossties added declined to almost the level seen a decade earlier.
Railroads also periodically replace or rebuild locomotives and freight cars. On average, new and rebuilt locomotives made up 4 percent of Class I railroad fleets between 1990 and 2001 (figure 56). The number of locomotives that were new or rebuilt varied from a low of 3 percent in 1992 to a high of 7 percent in 1994. Likewise, the number of freight cars that were new or rebuilt varied from 3 percent in 1992 to 6 percent in 1998.
1. Association of American Railroads, Railroad Facts 2002 Edition (Washington, DC: 2002).
2. U.S. Department of Transportation, Bureau of Transportation Statistics, National Transportation Statistics 2002 (Washington, DC: 2002), table 1-44 and appendix D, also available at http://www.bts.gov.
1 Rail companies with annual operating revenues of $266.6 million or more in 2001.
2 Ton-miles are calculated by multiplying the weight in tons of each shipment transported by the miles hauled.