<i>Consider the failure of the car&#x27;s master cylinder.</i><p>I realize it&#x27;s just one example to make a point, but automotive master cylinders don&#x27;t completely fail all at once since about fifty years ago. What causes a master cylinder to fail is a failure of the seals. But because modern master cylinders have &quot;dual channels&quot; (for lack of a better description), half of it might fail, but it&#x27;s so unlikely for both sides to fail at the same time I never even <i>heard</i> of it in my years as a professional mechanic, let alone actually seen such a failure. Though a self-driving car would still need to account for the fact that only half the wheels have functioning brakes.<p>Any other failures I can think of on modern cars are going to be so much of a failure that merely getting the car to the side of the road might be a challenge, let alone worrying about the bus full of nuns and orphans in front of you. Examples would be catastrophic tire or suspension failure (ball joint breaks loose, for example, making the car very difficult to steer).<p>On the flip side, it could be argued that late-model cars have worse failure modes. By that I use our Nissan Leaf as an example. There is no direct mechanical linkage on any part of the car that makes it stop, go, or steer. Parking brake is electrically actuated. Brakes are run on a wire. &quot;Gas&quot; pedal is wire. I&#x27;m <i>pretty</i> sure the steering is drive-by-wire, but I&#x27;d have to go back and look it up to make the claim with confidence. I&#x27;m sure there are redundancies, but I&#x27;m picturing an ECU letting its smoke out and then you might as well just let go of the wheel and pray to your preferred deity.<p>Anyway, this has been Captain Pedantic checking in, thanks for reading. I now return you to the point you actually trying to make.