Marine Transportation System (MTS)

Planes, trains, vessels, and automobiles—the lifelines of a fast-paced world—form the Marine Transportation System (MTS). The MTS represents an interlaced system of waterways, ports and intermeddle landside connections through which 95% of consumer goods are imported into the United States.


What is the MTS?

The MTS system is a seamless transportation network stretching from sea to sea, and everywhere in between, consisting of waterways, highways, rail, locks, ports and terminals. The frame is built on over 25,000 miles of waterways, the Great Lakes, the St Lawrence Seaway, 174,000 miles of rail connecting the contiguous states, Canada, and Mexico, as well as 45,000 interstate highways. Tying them together are over 3,700 marine terminals and 1,400 designated intermeddle connections. A coordinated, efficient MTS is critical to the growth and continued health of the nation’s commerce.

What does the MTS do?

Not merely the movers of goods, it also moves the millions of people who need to get from one place to the next. As the country becomes more congested, the MTS becomes a key part of the solution. On an annual level, the MTS currently transports:


  • 3.3 billion barrels (1.4 trillion gallons) of oil.
  • More than 2 billion tons of freight
  • 134 million ferry passengers
  • 78 million recreational boaters
  • More than 5 million cruise ship passengers
  • 110,000 commercial and recreational fishing vessels.

Environmental issues

The extensive network of waterways and adjacent shorelines on which the MTS is built is shared with delicate and irreplaceable ecosystems requiring responsible stewardship. As improvements are made to the MTS, issues of efficiency and economy must be balanced with safety and security for all the users of the network.

National Security issues

The MTS is also the backbone of the military transport system. Vessels assist the U.S. military in defending and serving our national interests both at home and abroad. The MTS is also the logical springboard for the rapid loading and transport of U.S. forces and materiel. Approximately 90% of all equipment and supplies for Desert Storm went through the MTS.

Growth Potential

As the world becomes more interconnected, the MTS will be called upon to meet the consequent demands. Changes expected within the next 20 years include:

  • Increase in commercial fishing, military, and ferry traffic
  • Nearly 6.5 million cruise ship passengers by 2002.
  • Tripling of the total volume of domestic and international marine trade.
  • 65% growth in recreational boating to more than 130 million annually.

Additional Sources of Information

  • An Assessment of the U.S. Marine Transportation System: A Report To Congress.
  • MTS: Marine Transportation System. A brochure published by the DOT.
  • Proceedings of the Marine Transportation Summit held Nov. 1998

The Thirteenth Coast Guard District Public Affairs Office (dep) created this page on December 27, 1999 and last modified it June 26, 2002. This page may be reproduced locally. If any changes are needed please notify D13 (dep) at 206.220.7237. More Coast Guard information can be accessed at and a complete listing of these fact sheets can be found at