I have said for years, and still say, that such a rule/statement makes it really hard for a single driver to hitch and unhitch!
Well, that would not exactly be "put to" when you are halfway through the process one way or another, now would it. You need to have common sense about it.
Agricultural/draft drivers do not do it that way. The Amish don't do it that way. None of the pioneers or those historically using horses for transport (except the monied elite who could afford grooms) to my knowledge did it that way. It was simply impractical! Why the ADS has decided to make such a blanket statement of what is "correct" I do not understand.
Most of the bad bolts I've seen happened in spite of a driver on the box and in fact might have been prevented by someone at the horse's head when the driver wasn't able to do a darn thing.
Most of the populations you listed use(d) their horses more than the average recreational/show driver. Face it, those horses know their "job" a whole lot better than our "pampered pets". (Most of those populations use(d) MUCH more strict methods to get the horse to "behave" than what is popular nowadays, too!
) Yes, I have seen bad bolts with a driver on the box (heck, I've been one of those drivers), but at least with a driver on the box you stand some chance of stopping the horse. With only someone on the ground, that horse is surely going to get away. I was just talking with a recreational driver this weekend who talked about having to bail off a vehicle at times. She asked me if I would just become part of the crash, and I said under no circumstance is the driver to leave the vehicle. If you put a horse to a vehicle, it is YOUR responsibility to stay with it and see if you can get it stopped before it runs into something or someone else. We haven't had a major "crash" BECAUSE we HAVE stayed with the vehicle and got it stopped before the crash happened.
I have not seen a horse get away from a driverless vehicle yet, and I think that is mostly because of that "strong suggestion" that ADS has. I have on numerous times either told someone they needed to have someone on the box (as I myself was told by a TD a number of years ago even before it was in the rulebook), or volunteered myself to climb on the box if the header wasn't comfortable doing it, i.e. not really a "horse-person".
Myrna