Frankly, I’m already tired of the discussion. It’s not as if humans don’t already get into situations like this, and make (or not make) decisions. At least, I have.
When I was a grad student, I bought my first (very used) car: a monstrous 1966 Plymouth Fury III. I was working a part-time job about five miles away from where I lived. I normally commuted by bike, but the day after buying the car, and before I had registered or insured it, it rained. So, I decided: “what could go wrong? I’ll drive.”
Of course, something went wrong. While I was driving home, the brakes were soft. And as I was driving toward Stanford, approaching the underpass on Embarcadero, going downhill, they failed completely — while I was following a Mercedes, in heavy traffic. And I thought, quite literally, should I plow into the Merc or drive into a bridge abutment. So, debates about, “should the car take out the school children or the elderly lady” aren’t entirely academic to me.
Morally, I just froze. And whatever I might have thought that I should do, it was clear that the moral logic was totally irrelevant to what I was actually going to do, which was nothing at all. It certainly didn’t occur to me to think through all the ramifications of my situation: if I drove into the bridge abutment, sparing the Mercedes and its driver, would I have created a greater danger for the cars in back of me? If I took out the Mercedes and its driver, would I be killing the venture capitalist who was going to fund Google in a few years? Was the Mercedes possibly even more massive and collision-resistant than my monstrous Plymouth (man, that was a big car)? You can spin this all sorts of ways, and most of them are pretty silly.
At the last possible instant, I realized why emergency brakes were invented. I managed to get the car under control, drive under the underpass, and park it in a parking lot. I walked home and retrieved the car sometime after midnight, when there wasn’t anyone on the road.
But here’s the real moral of the story: a self-driving car wouldn’t have had to figure out why the emergency brakes were there.