Designated US Marine Highways

Designated US Marine Highways

Source: Adapted from U.S. Department of Transportation – Maritime Administration.

In 2007, the US Maritime Administration initiated a program trying to promote the use of the national waterway system, which includes rivers, channels, coastal navigation routes, and the St. Lawrence Seaway / Great Lakes system. In order to underline the possible complementarity between the highway and waterway system, analogies were created. Specific waterway corridors were identified as ‘marine highways’, and each was given a designation corresponding to a similar Interstate Highway using the prefix ‘M’ instead of ‘I’. For instance, marine highway M-95 that spans the eastern seaboard corresponds to the I-95 highway that follows a similar path. There are several expectations behind this strategy:

  • Reduce congestion on the Interstate Highway and, to a lesser extent, on the railway system. It is expected that additional cargo, particularly heavier cargoes, may switch from rail and road to waterways. In addition, this may reduce maintenance costs for road and rail systems.
  • Reduce air emissions per ton-km since waterway transportation is much more energy-efficient than road and rail. This could help make the national transport system more sustainable.
  • Provide additional transport options for cargo that complement more than compete with existing transport systems and add a redundancy level in the system. The expectation is that the competitiveness of the American economy would be improved.

Yet, waterway transportation in the United States is facing several challenges. The first is related to the geography of commercial flows, which are dominantly east-west while the waterway system has a north-south orientation. Very few ports in North America are at the head of a waterway system enabling extensive hinterland access. The only major exceptions are New Orleans and Montreal. The second is the established competitiveness of road and rail transportation, leaving the use of waterways to niche markets such as long-established bulk trades (grain, coal) or project cargo. Waterways have difficulties fitting in contemporary freight distribution systems that lean more on time and reliability than transport costs.