While driving it's very hard to use the Yes/No buttons, while paying attention to the road and hazzard that was just announced. I would suggest a large control with swipe left/right, that is easy to use without looking at the phone screen for long, and without trying to be very precise with your fingers on the screen. You could still split it in two areas, so a click on the left or right still work as Yes/No, just to avoid annoying users that are accustomed with the current UI. As it is now, I only use those buttons when I'm a passenger, never as a driver.