I, for instance, still lay the "pole" part of my whip along the outside hip of my horse when I ask him to step over in the cart. Carriage drivers shake their heads and tell me I'm terrible for this. But ya know, I'm coming from a ridden trail course background where I'd be picking up my inside rein and using my outside leg at the girth to ask him to step over. They are coming from a dressage background where you're providing a boundary with your inside rein and asking the horse to step into it with give and release on the outside rein. I taught my horse different signals.