Why the MTS Matters

The U.S. Marine Transportation System (MTS) is the primary system by which goods enter and leave the United States (U.S.). During 2018, waterborne trade through U.S. ports accounted for more than 42 percent of U.S. international trade by value, moving $1.76 trillion of goods. Approximately 2.3 billion tons of domestic and foreign commerce are carried annually on the U.S. inland waterways. The MTS touches virtually every aspect of American life-from the clothes we wear, to the cars and trucks we drive, to the food we eat, to the oil and natural gas used to heat and cool our homes.

The MTS of the United States encompasses a vast network of waterborne transportation along our Nation's marine coastlines, our inland river systems, and the Great Lakes. More international trade is carried via the MTS than any other mode of transportation, providing critical support to the entire U.S. economy. The MTS is commonly referred to as a "system of systems" because of the many components that combine to facilitate the water and land supply chains. The MTS comprises a variety of components including: navigable waterways and channels; ports and marine terminals (liquid, dry, and breakbulk as well as container); intermodal connection pathways between waterborne and land transportation systems (highways and rail lines); vessels (commercial, military, and recreational); infrastructure (locks and dams); and offshore continental shelf structures (oil exploration and wind energy facilities).

The U.S. MTS includes:

  • 25,000 miles of navigable channels
  • 239 locks at 193 locations
  • More than 3,700 marine terminals
  • 324 shipyards
  • Almost 13.1 million U.S. cruise passengers in 2018
  • 45,000 aids to navigation
  • 75,000 fishing vessels
  • 1,400 designated intermodal connections
  • 233 ferry operators providing service through 515 terminals