It is this exact thing that I try to figure out: "Traditionally" you would press the W repeatedly in order to accelerate sequentially, the X to slow down or the S to stop moving entirely. But when talking pedals things get a bit tricky. I mean you can associate the acceleration pedal with W, but then, as long as the driver keeps his foot on it, the tank will reach maximum speed, without him having to depress his foot further down. On the other hand, one can associate the "pedal up" position with S, but this brings the vehicle to a very abrupt halt, instead of slowly reducing speed. And what about reverse? How do you associate reverse with the acceleration pedal since the gear stick is practically useless?