I think I came up with a solution for semi trucks so we know when to stop while backing up. I finally got tired of getting out to make sure I don’t hit the back of a trailer or something else. As of today I used some rope and a commercial tire chock, which I always carry in my truck, anyway. Starting from the end of the rope, I have placed markings with a permanent marker every 6 inches (length between tandem holes) so I can use this regardless of the position of my trailer tandem.
Has anyone done something like this? Or, how can this be perfected?