What Is Intermodal Shipping?

Intermodal shipping, also called intermodal transportation, is moving freight by more than one mode of transportation. The Federal Highway Administration (FHWA) freight glossary describes it as using more than one mode of transportation in moving persons and goods, with the modes meeting at an intermodal terminal, a location where links between different transportation modes and networks connect.

FHWA's example is a shipment moved over 1,000 miles that could travel by truck for one portion of the trip and then transfer to rail at a designated terminal. The container makes that transfer practical: FHWA defines containerized cargo as cargo transported in containers that can be transferred easily from one transportation mode to another. A container is typically ten to forty feet long and used primarily for ocean freight, and for travel to and from ports, containers are loaded onto truck chassis or railroad flatcars.

FHWA's freight glossary names the ways rail carries intermodal freight:

• Container on flatcar (COFC): containers resting on railway flatcars without a chassis underneath.
• Trailer on flatcar (TOFC): transport of trailers with their loads on specially designed rail cars.
• Piggyback: a rail and truck service. A shipper loads a highway trailer, a carrier drives it to a rail terminal and loads it on a flatcar, and the railroad moves the trailer-on-flatcar combination to the destination terminal, where the carrier offloads the trailer and delivers it to the consignee.
• Double-stack: railcar movement of containers stacked two high.

Both move freight between modes at a terminal, but they treat the cargo differently. FHWA defines transloading as transferring bulk shipments from the vehicle or container of one mode to that of another at a terminal interchange point. In containerization, the commodities are not re-handled in shipment until they are unloaded at destination: the container changes mode and the goods stay inside.

On the road legs, federal rules have their own term. FMCSA rules at 49 CFR 390.5 define intermodal equipment as trailing equipment used in the intermodal transportation of containers over public highways in interstate commerce, including trailers and chassis, and an intermodal equipment provider as anyone that interchanges that equipment with a motor carrier under a written interchange agreement or is contractually responsible for maintaining it.

A distributor moves a container 1,000 miles from a supplier's plant to its warehouse. A trucker drays it 30 miles to an intermodal terminal, the train carries it 950 miles, and a second trucker delivers it the last 20 miles: 30 + 950 + 20 = 1,000 miles. The goods are loaded once at the plant and unloaded once at the warehouse.

Shopify tracks inbound stock as inventory transfers. When you process a transfer, Shopify automatically creates a shipment, and if you need to manage multiple shipments or add tracking information, you can manage shipments separately. If your supplier ships items in multiple shipments, you can receive each shipment individually as it arrives.

Uncap's guide to B2B shipping on Shopify starts from the same reality: "Manufacturers and distributors deal with multiple variables, dimensions, packaging, weight, multi-origin fulfillment, LTL freight, zoning, carrier rules, and negotiated rate tables."

• Drayage
• Demurrage
• Cross-docking
• Bill of lading
• Freight forwarder
• LTL freight (less-than-truckload)

• FHWA: Freight Glossary
• eCFR: 49 CFR 390.5, definitions