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 < Back to Contents  Chapter Thirteen: TRANSPORTATION Passengers Freight Traffic Traffic Deaths Bicycles
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Traffic |
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In an effort to define the scope of the nation’s road system and the distances Americans travel on it, the U.S. Department of Transportation reported in 1997 that “the sheer physical size of the transportation network is difficult to comprehend. Its 4 million miles of roads would circle the globe more than 157 times or go to the moon and back more than 8 times. In 1995, cars and light trucks—the vast majority of them personal vehicles—were driven 2.2 trillion miles in the United States. This is literally an astronomical distance, nearly one-tenth of the distance to the nearest star outside the solar system. A more down-to-earth measure: the distance traveled by the average car or light truck in the United States in 1995 equaled a journey nearly halfway around the earth.” The upper chart shows how the number of registered motor vehicles per mile of surfaced road (including city streets, county roads, state highways, and the interstate highway system) climbed from two in 1910 to fifty-seven in 1997. Because the chart is based on road mileage, it understates the effect of multiple lanes, which increase effective road capacity. On the other hand, it ignores the increased mileage of individual vehicles, which has an opposite and probably greater effect. The average daily travel per vehicle increased by 68 percent between 1980 and 1997, while miles of paved road increased by 14 percent. As the lower chart shows, the number of miles traveled by motor vehicles in the United States increased steadily throughout the century. Individually owned passenger vehicles accounted for most of this travel. The overwhelming majority of employed persons got to their workplaces by private motor vehicle and most of them drove alone. Only 5 percent of commuters used public transportation. Many parents drove their children to school. Nearly all shoppers drove to the supermarket or the mall. Source
Notes HS series Q 56, Q 152, and Q 199; SA 1984, table 1051; SA 1997, tables 996 and 1010; and SA 1999, tables 1020 and 1439. For the size of the transportation network, see Bureau of Transportation Statistics, Transportation in the United States: A Review (1997), page 2, at www.bts.gov (accessed September 26, 2000). For the average daily travel and paved roads, and the use of public transportation versus privately owned cars, see SA 1997, tables 1014 and 1016.
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