Your current production Ford has a computer directly controlling the throttle plate and transmission shifting (no mechanical connection). Computers also intervene in the brakes and steering. You have adaptive cruise control (detects vehicles and adjusts speed), lane assist (helps you stay in the lane and warns you if you change lanes without signaling), stability control,and does hands off parallel parking.
What if any of those fail?
In a few years, going to fully autonomous will just be a small step.