Source: Intermodal Association of North America & American Association of Railroads.
Rail transport trends in the United States indicate a significant shift in intermodal traffic toward containerized freight. While rail intermodal container traffic (container on flat cars; COFC), both ISO and domestic, increased, the number of trailers carried by rail (trailers on flat cars; TOFC) declined. This represents a significant shift in the TOFC/COFC balance: 55%/45% in 1990, 25%/75% in 2000, and 9%/91% containers in 2020. TOFC has thus become a marginal segment of intermodal transportation used for niche services, most of which are point-to-point.
In 2005, 58% of the containers handled were international (maritime) containers, while domestic containers accounted for 23% and trailers for 19%. About 25% of all international cargo moved by rail is transloaded into domestic containers. COFC traffic peaked in 2007 and declined in 2008 and 2009 due to a decline in import demands. As of 2018, intermodal rail traffic recovered to pre-2006- 07 traffic levels. The COVID-19 pandemic led to a decline in intermodal rail volumes in 2020. However, the surge in demand from late 2020 resulted in record intermodal traffic levels in 2021, creating several pressures on system capacity. This raises the question of whether intermodal rail has reached its market potential in the United States or if there is additional growth to be expected.
One of the core advantages of COFC versus TOFC is double stacking, which involves a much higher utilization density of rail assets. Several prominent American trucking companies are also converting to containerization, thus relying on COFC as opposed to TOFC. For instance, in 2009, citing energy and cost advantages, major LTL shipper Schneider National converted its entire intermodal fleet to containers. JB Hunt, with the largest fleet of domestic 53-foot containers, has also converted to COFC operations.