Brakes are not usually "by-wire" on a car that is able to automatically brake. The brake pedal is still physically connected to the brakes. Same for the steeri

Brakes are not usually "by-wire" on a car that is able to automatically brake. The brake pedal is still physically connected to the brakes. Same for the steering. BMW for example has a method where the steering wheel is physically connected but the computer can add corrections to it via a clever set of gears. See here: https://en.wikipedia.org/wiki/Active_steering https://en.wikipedia.org/wiki/Active_steering If the computer (or electric steering motor) fails the steering wheel still works.