Allow for a slider, 50% speed being the default and current run speed. My proposal is to have the slider be exponential. The higher the bar, the more increase it gives exponentially, and vice versa. OR have a speed variable that can be tied to an avatar. This might be the better alternative, to allow walk animations to match the movement speed per avatar.
I know it can be frustrating to get around larger maps, and with larger avatars running in place (or so it appears)