It had better be designed to tolerate single points of failure, if not multiple. Similar issue exists with today's airplanes. I have never experienced a power steering failure though I would imagine it can be difficult to avoid a crash if it were to occur. I checked casually and it appears that Tesla's yoke steering does require multiple turns of the wheel/yoke to go lock to lock. Bizarre and probably destined to kill someone. I like Lexus' version better.