That is correct - it isn't really an 'accelerator'. It is a forward and a reverse treadle pedal. When you lift your feet off the treadle (either pedal), the hydro flow stops to the wheel motors, and the unit slows and stops. Pulling your feet off the pedals suddenly will bring it to a quick, controlled stop - it doesn't, however, simply lock the wheels - the flow slows quickly, and then stops. It acts like a very fast, damped brake.
-Rob /forums/images/graemlins/grin.gif