section_path: Economy/Transportation
section_name: Transportation
paragraph_text: Transportation
  
  The 4 million miles (6.4 million kilometers) road network, owned almost entirely by state and local governments, is the longest in the world. The extensive Interstate Highway System connects all major cities and is funded mostly by the federal government but maintained by state departments of transportation, supplemented by state expressways and some private toll roads.
  
  The U.S. is among the top ten countries with the highest vehicle ownership per capita (850 vehicles per 1,000 people) in 2022. A 2022 study found that 76% of U.S. commuters drive alone and 14% ride a bicycle, including bike owners and users of bike-sharing networks. About 11% use some form of public transportation.
  
  Public transportation in the United States is well developed in the largest urban areas, notably New York City, Chicago, Boston, Philadelphia, and Portland, Oregon; otherwise, coverage is generally less extensive than in most other developed countries. The U.S. also has many relatively car-dependent localities.
  
  Long-distance intercity travel is provided primarily by airlines, but travel by rail is more common along the Northeast Corridor, the only high-speed rail in the U.S. that meets international standards. Amtrak, the country's government-sponsored national passenger rail company, has a relatively sparse network compared to that of Western European countries. Service is concentrated in the Northeast, Illinois, and the West Coast.
  
  The United States has an extensive air transportation network. U.S. civilian airlines are all privately owned. The three largest airlines in the world, by total number of passengers carried, are U.S.-based; American Airlines became the global leader after its 2013 merger with US Airways. Among the busiest 50 airports in the world, 16 are in the United States, as well as five of the top 10. The world's busiest airport by passenger volume is Hartsfield–Jackson Atlanta International in Atlanta, Georgia. In 2022, most of the 19,969 U.S. airports were owned and operated by local government authorities, and there are also some private airports. Some 5,193 are designated as "public use", including for general aviation. The Transportation Security Administration has provided security at most major airports since 2001.
  
  The country's rail transport network, the longest in the world at 182,412.3 mi (293,564.2 km), handles mostly freight (in contrast to more passenger-centered rail in Europe). Because they are often privately owned operations as well, U.S. railroads lag behind those of the rest of the world in terms of electrification.
  
  The country's inland waterways are the world's fifth-longest, totaling 41,009 km (25,482 mi). They are used extensively for freight, recreation, and a small amount of passenger traffic. Of the world's 50 busiest container ports, four are located in the United States, with the busiest in the U.S. being the Port of Los Angeles.