To refine this a bit, what you could do is make 'zone' near the extreme of the accelerator pedal travel which will provide full acceleration. But then another zone right at the end of the travel where the acceleration would cut out (and perhaps not just completely cut out instantly, but gradually ramp down as it gets very near the end of travel down to nothing at the very end of travel).
What that would do is make it easy enough to get completely full acceleration out of your vehicle, but you would have to do so intentionally by finding that sweet spot--which is what we want here. You make the sweet spot plenty wide & easy to find.
But if you panic & slam the accelerator to the floor, you get no acceleration at all--which is also what you want.
Once people are used to this system (which would only take a couple minutes driving I would guess) the only times you'd be pressing the accelerator to the floor would be when you were #1 panicking for some reason #2 actually trying to apply full brakes.
In neither instance do you want to give that person full acceleration (the last thing you want is a panicky person at the helm of a motor vehicle with full acceleration, and the person trying to apply the brakes obviously doesn't want full acceleration either).