How do you solve this problem for those of us in Colorado (or other non-flatlands) where nearly every drive involves mountains and hills. Would the idea be that in the dead zone, the car is smart enough to increase or decrease horsepower to adapt to these conditions and retain 0 acceleration or...? I think you would run into the same problem that cruise control runs into in the mountains - we don't have variable ratio transmissions, so at some point going up a hill it has to shift down a rev in order to stay the same speed. Doesn't work very well.
Yes, the whole idea is the car is smart enough to maintain a speed. You're right about having problems in the mountains. If someone doesn't want their car to downshift, they'd just slow down by lifting and returning to the zero point. I think it would be a little better than cruise control in the mountains, but not much.
I can't speak for tricky, but variable ratio transmissions do exist. They're called CVTs and while they're not super popular (there were some issues w/ them in the 80's), they're slowly being reintroduced to the market.
