Why do they drive on the left in some countries and on the right in others? It goes back to the fact that most are right-handed. Long before we had modern weapons such as and , people had to do battle using and . Now if you are right-handed, you wear your sword on the left, so that you can it out rapidly with your right hand. But with that , dangling scabbard encumbering your left side, the only way you can mount a horse is by throwing your free right leg over him. And unless you are in a movie and want to wind up sitting backward on your steed, that means that the 's' head has to be pointing to your left. To this day we still to be saddled and mounted from their left sides. Now that you are mounted, you will want to stay on the left side as you down the road, because anyone coming toward you will be on your right, and if that someone turns out to be an , you can out your with your right hand and be in position to run the scoundrel through. Thus, prudent horsemen have always ridden on the left side of the road.