What is intermodal freight?

The defining feature of intermodal is that nobody touches the freight. An import container can come off a ship in Los Angeles, ride a train to Chicago, and be delivered by truck to a warehouse, all with the original seal on the door. That is the opposite of transloading, where the goods are moved into different equipment.

North American intermodal volume is split roughly evenly between two flows. International containers carry imports and exports inland from the ports. Domestic 53-foot containers move freight that never touched a ship, competing directly with long-haul trucks.

Rail intermodal comes in two forms. COFC, container on flatcar, puts a container on a rail well car, often stacked two high. TOFC, trailer on flatcar, puts an entire over-the-road trailer on the train. Both are defined in federal rail regulations, and both used to matter.

Today it is almost all containers. Trailers were more than half of US intermodal traffic in 1990. By 2025, according to the Intermodal Association of North America, trailers were only about 2.5% of the roughly 18.5 million intermodal units moved in North America, and trailer volume was falling fast.

Rail wins on distance. The Association of American Railroads puts freight rail at close to 500 ton-miles per gallon of fuel, several times what a truck manages. But every intermodal move pays for extra handling: lifts at the ramp, the chassis, and a truck at each end. Those fixed costs only pay off when the rail leg is long.

Transport researchers put the US breakeven against truckload at around 750 miles, and the average rail haul is far longer than that. Below it, the drayage and terminal costs eat the savings. That is why intermodal lanes cluster on long corridors like Los Angeles to Chicago or Dallas.

The train does not go to the warehouse. Every intermodal shipment starts with a drayage move to the ramp and ends with another from the destination ramp to the customer. Those two short legs are where most of the coordination lives: appointments at the rail terminal, chassis availability, and the free time the railroad allows before storage charges start.

They are also where the time goes. Drivers describe rail yards where getting in and out takes four hours on a bad day, time that eats into their hours of service and rarely gets billed. When the ramps back up, as they did in Chicago and other inland hubs in 2021, containers sat for more than ten days and Union Pacific temporarily paused West Coast service to Chicago to clear them.

The rail rate is the part of an intermodal move everyone negotiates. The part that erodes the margin is time on the ends. Railroads charge storage once a container sits at the ramp past its free time, and the ocean carrier's per diem keeps running on an international box for as long as it is out, including the days it spends on the train and waiting for a dray.

A shipment that looked cheaper than truckload on the rate sheet can end up more expensive once ramp storage and per diem are added. The difference is almost always visibility: knowing when the box is available at the ramp and getting a truck there before free time runs out.

Most domestic intermodal is sold by intermodal marketing companies and asset-based providers, led by J.B. Hunt, with Hub Group and Schneider behind it, who buy rail capacity and arrange the drayage. The rail network belongs to the Class I railroads: BNSF and Union Pacific in the West, CSX and Norfolk Southern in the East.

That split may change. Union Pacific and Norfolk Southern have proposed a merger that would create the first coast-to-coast railroad. The Surface Transportation Board accepted the revised application in May 2026, and the review is ongoing, with the railroads targeting a close in 2027.