total: 240,000 km mainline routes (nongovernment owned), standard gauge (1.435 m) (1989)
See also Transportation in the United States.
... 18 to 24, 29.9% from 25 to 44, 23.8% from 45 to 64, and 7.9% who are 65 years of age or older. The median age is 35 years. For every 100 females there are 95.1 males. ...