California accounts for 9.6 percent of the total fleet. California, combined with Illinois, Texas, and Pennsylvania, accounts for more than one-quarter of the total fleet. The 5-axle or more fleet contains data for various types of truck combinations whose total number of axles is greater than or equal to five. Nationwide, the 5-axle or more fleet increased by 21.9 percent from 1987 to 1992. The Western region increased by 53.3 percent in the same time period.
Further analysis is done by truck configuration by region and body type.