Yeah, Land-Tug is the perfect description, and an elegant solution. It's an engineers wet dream and a designers nightmare. But the on/over, the road pictures blew me away, made me think of farm tractors hauling machinery over the road at 25 mph.
I was surprised at finding the origins of tractor trailer and semi, one of the guilty pleasures of these multi-hour wanderings down rabbit holes that make people cluck and pat me on the head.