This is 'just' an option that alotta ppl 'think' of... but never really remember... 'pedals' are just an extensional leverage unit that pulls/pushes 'another' unit to a certain, variable amount of either contraction or the other(e.i.- throttle, brakes, rudder on planes/some boats, etc...).
However, 'hand-grips', like on bicycles, 'can' be an option to 'pedals'. Also, by removing the NEED for ones feet to be positioned, stationary, for gas/brakes, one can maneuver ones footing to accommodate balance/shifting... just an idea till you get pre-fab ones.