Full explanation
Intermodal shipping moves freight using multiple transportation modes — typically truck, rail, and/or ocean vessel — in standardized containers that transfer between modes without requiring the cargo to be unloaded and reloaded. The most common domestic intermodal combination is truck-rail-truck: a drayage carrier picks up a container at origin, delivers it to a rail terminal, the container rides by rail for the long-haul portion, then another drayage carrier delivers it to the final destination. Intermodal is typically 10-20% cheaper than over-the-road trucking for distances exceeding 750 miles, though transit times are 1-3 days longer. The US intermodal market handles approximately 14 million container movements annually. Standard container sizes are 20-foot (TEU) and 40-foot (FEU), with 53-foot domestic containers also common. Truck Graph identifies intermodal carriers using the carrier_operation field in FMCSA records, currently tracking carriers with intermodal indicators across all 50 states.
Frequently asked questions
What's the difference between intermodal and multimodal?
Intermodal uses a single contract with one carrier responsible for the entire move across modes. Multimodal involves separate contracts with each carrier for each leg. The terms are often used interchangeably in practice.
When is intermodal cheaper than trucking?
Intermodal typically becomes cost-competitive at distances over 750 miles. For lanes over 1,500 miles, intermodal can save 15-25% compared to over-the-road trucking, though transit times are longer.
Do intermodal carriers need special authority?
Yes. Intermodal drayage carriers need standard FMCSA operating authority. They also often need TWIC (Transportation Worker Identification Credential) cards for port access and specific terminal agreements.