TRB’s National Cooperative Freight Research Program (NCFRP) Report 5: North American Marine Highways explores the potential for moving intermodal containers on chassis, non-containerized trailers, or rail cars on marine highways in North America. The report includes an assessment of the conditions for feasibility; an analysis of the economic, technical, regulatory, and logistical barriers inhibiting greater use of the marine highway system; and potential ways to eliminate these barriers.