total: 240,000 km mainline routes (nongovernment owned), standard gauge (1.435 m) (1989)
See also Transportation in the United States.
... age of 18, 8.7% from 18 to 24, 29.5% from 25 to 44, 21.0% from 45 to 64, and 13.5% who are 65 years of age or older. The median age is 35 years. For every 100 females ...