"The Transportation Statistics Annual Report describes the Nation’s transportation system, the system’s performance, its contributions to the economy, and its effects on people and the environment. This 21st edition of the report is based on information collected or compiled by the Bureau of Transportation Statistics (BTS), a principle Federal statistical agency at the U.S. Department of Transportation.
Nearly 4.2 million miles of roads, more than 19,000 public and private use airports, about 140,000 miles of freight and passenger railroads, 25,000 miles of navigable waterways, and nearly 2.7 million miles of oil and gas pipelines connect the Nation’s people and businesses across the continent and with the rest of the world.
The estimated value of U.S. transportation assets in 2014 was approximately $8.1 trillion. The public owns 50.5 percent of the total transportation asset value, mostly highways and streets, but also publicly held transit facilities, airports, and numerous seaports, inland ports and terminals, and other facilities related to water transportation. Private companies own 31.5 percent of transportation assets, including railroads, pipelines, trucks, planes, and ships. Personal motor vehicles account for the remaining 18.0 percent...."