Final answer:
Roadrailers are specialized trailers used in intermodal transportation, specifically in the Triple Crown Service. This service focuses on transporting high-value goods.
Step-by-step explanation:
Road railers are specialized trailers that can be transported on both roads and railways.
They are typically used in intermodal transportation, which involves the combination of different modes of transport for the movement of goods.
The Triple Crown Service is a specific type of intermodal transport that operates in the United States.
It is a joint venture between Norfolk Southern Railway and Union Pacific, and it focuses on the transportation of high-value, time-sensitive goods such as automobiles and electronics.