Intermodal freight transportation involves multiple modes of transport, for example, cargo is picked up at the shipper’s facilities in a trailer or container, driven by truck to an intermodal rail terminal, loaded onto a railroad flatcar, moved by train to another rail terminal near the destination, and then delivered to its final destination by truck. 

Intermodal trains run only from specific stations (intermodal terminals) and often have different routes compared to other types of freight trains. For origin-destination combinations where intermodal trains use a different route than general merchandise trains, the intermodal route option will provide a more realistic route and mileage than the "practical" (default) route option.