It’s not that the horse suddenly realizes the carriage is behind them. There are some big gaps in the training indeed if the horse doesn’t know he has a carriage behind him. :eek::winkgrin: It’s that you no longer have a bit and reins with which to control the horse. I solve this problem for myself by having a halter under the driving bridle. I use nose-buckle halters with throat snaps, very easy to remove if need be (for example before entering the show ring) and easy to put back on. My halters were made to match the harness, they’re unobtrusive but there if I need them. Working alone at shows or at trail drives many times there is no choice but to harness and put to while the horse is tied to a trailer. Likewise, many times I drive alone at my home barn and when we return to the hitch rail it’s a simple matter to hop down and snap a leadrope to the halter ring. Horse is then secure and I can have the reins in my hands at all times.
Wendy, many of your questions seem to be theoretical in nature and will be answered for you via OJT after you’ve put in some time and mileage actually driving. There is no substitute for hands-on experience, hopefully under the guidance of a good trainer. Also, try to attend driving events, watch what happens. You’ll get an eyeful of things done right and (unfortunately) things done very wrong. After several months of driving, I bet you’ll have the answer for yourself as to whether or not you can or should leave your horse hitched and unattended. :lol: It’s not something I would do nor have the expectation that I could do it. You learn to plan ahead and cover the what-ifs when you drive. As has been noted elsewhere, most of our horses don’t put in nearly enough hours of work to be tired enough to stand like statues during rest breaks. Some do, such as the mules you saw at the frontier village. On the other hand, there’s a chance, maybe a good chance, that you weren’t there the day the mules broke their reins and wandered off with the wagon attached. We don’t get to see the outtakes very often.