Nearly all major U.S. ports have National Highway System (NHS) connectors, which are the public roads leading to major marine terminals as well as the rail connection via on-dock or a nearby intermodal container transfer facilities (ICTFs). The NHS includes the Interstate and U.S. highways as well as other roads important to Nation’s economy, defense, and mobility.
According to the Freight Analysis Framework, about 58 million tons (7.8 percent) of U.S. water imports were moved domestically by rail. Only about 13 million tons (22.2 percent) of the U.S. water imports were moved by rail less than 100 miles. About 2/3 of the tonnage moved 749 miles or less, more specifically about 34 million tons (58.3 percent), and a 1/3 moved of the tonnage moved 750 miles or more, more specifically about 24 million tons (41.7 percent). Many rail lines are configured to handle intermodal shipping containers, particularly double-stack trains.
For comparison, truck moved about 136,204 (41.8 percent) of the U.S. water imports less than 100 miles. Trucks primarily handle the short, local trips while rail handles more intermediate and long-distance, intercity trips. If a marine terminal does not have an on-dock rail connection, drayage trucks will ferry a steady stream of shipping containers to and from a nearby ICTF. Trucks moved 299 million tons (91.8 percent) of their tonnage 749 miles or less, only 27 million (8.2 percent) were 750 miles or more.  The following figure shows the NHS connectors, which connect our Nation's ports to local markets, ICTFs, or the hinterlands.