Art Howes posted: I don't think my model railroad is long enough to give justice to a unit train.
Interesting thought. Could a train made up of just two tank cars going from a central location where they were filled out to a local distributer two towns away be considered a unit train?
The definition of a unit train does not include a number of cars. I did find one association that said their unit trains have 65 to 200 cars, but I think a 20 car unit train could be realistic for modelers.