The United States Army has a truck called the Load Handling System. How is a truck a "system?" We called the truck and trailer an "LHS System," apparently for the sake of redundant repetitiveness. I think that it is a clever system. The front axle of the trailer pivots and whenever you back up, the trailer buckles, because it is easier for the front axle to move (sideways) than for the rear axle to roll backwards.
However, when you have the front wheels straight, you can lock the pivot point, but it always takes a while to get those wheels straight.