Seriously, there are a lot of things you can do before you hook up your horse to that beautiful vehicle. I made a tow bar and was pulling an inner tube, a tire and then a log around my arena before my horse was 16 months old. He already stopped on a dime from voice command and did pivot turns from the ground work we had done. He pulled 6 foot long firewood logs out of the woods when he was 18 months old. I broke him to the cart when he was two. He is 3 1/2 now and I have never had a problem when driving him although I have been very careful not to over-face him or put him in a dangerous situation. There is too much snow on the ground to drive right now so we are back to ground work and I am doing some things with him I should have done during the summer.