And I think the main reason why I would be leary of driving a horse is because IF the horse does ever totally freak out, there is absolutely no way to reverse the flight instinct, because the cart just scares him more...and then if he does get loose like that, other people, and horses get hurt, because the carts add so much more complication to the matter. Atleast on the back of a horse, you can manuveur and get out of the way of the said horse, or someone could ride along side, and capture loose horse, without getting hurt, like with the carted horse.
I have driven horses before, and it is fun, just wouldn't want something like that to ever happen! Actually several years ago, something like that DID happen with one of my mom's horses...he got freaked out for some reason, dumped her, and proceded to head toward the road...the cart came undone, so he was just dragging his harness gear, but he was still freaked out...I had been leading my mare, and I let her go (she actually just followed me) and shooed the other horse out of the road and back into our yard, and just let him go up the driveway, where he stopped by our garage. Mom's hip was messed up over that one, and she never drove him again, because he wigged out everytime you tried to hook him up to the cart; I wasn't home enough to retrain him for her...she just didn't know how to get through his fear.
"The ideal horseman has the courage of a lion, the patience of a saint, and the hands of a woman..."