The median age of the automobile fleet in the United States increased, by 19 percent, from 7.5 years in 1994 to 8.9 years in 2004. The median age of the truck fleet,1 by contrast, began to increase in the early 1990s but has declined since 1997 as the purchase of light trucks increased (figure 2-10). As a result, the truck median age of 6.6 years in 2004 is less than its 7.5 years in 1994 .
The age of transit vehicle fleets varies by transit and vehicle type and tends to fluctuate (figure 2-11). The average age of heavy-rail passenger cars and ferryboats increased 7 percent and 10 percent, respectively, between 1993 and 2003. By contrast, the average age of full-size transit buses decreased 14 percent .
The age of fleets as a measure of condition is not very precise. Because of the different characteristics of vehicle fleets across the modes-some serving freight and others passengers, some owned predominantly by businesses, and others by individuals-the measure varies widely.
1. U.S. Department of Transportation, Research and Innovative Technology Administration, Bureau of Transportation Statistics, National Transportation Statistics 2005, tables 1-25 and 1-28, available at http://www.bts.gov/, as of June 2005.
1 This includes all truck categories: light, heavy, and heavy-heavy.