Intermodel?

I see alot of JB Hunt trucks in my area pulling intermodel trailers (look like rail cars). I know they pick them up at a rail yard. Do they take them to another rail yard or do they deliver them to customers like a van trailer? I know this is probably a stupid question but I really don't know.

From what I understand, a customer will have a container shipped by rail to a certain point, then they pay for it to be trucked the rest of the way in to the final destination. Rail can only go certain places, therefore the final trip has to be by truck. I see a lot of that around my area too.