The U.S. transportation network provides a high
degree of personal mobility and freight activity. In
1999, the transportation network supported 4.8 trillion
passenger-miles and about 3.9 trillion ton-miles.The data
in this section confirm that local and long-distance travel
and freight shipments continue to grow. Several factors
influence this growth: greater vehicle availability, reduced
travel costs, population increases, an expanding economy,
and higher consumer incomes.
