Understandable. Think about it like this: If you're running in a straight line, you can keep your speed, however if you try to make any turn, you lose speed. I know this game doesn't have speed, but it's comparable. I noticed the other day while using cruise control on my car, my gas efficiency meter stayed even, but if i even made a lane change the efficiency dropped dramatically. Straight = easy, turns = taxing.

More...