That's exactly what I argue about. In a rare (but very important) occasion where risk taking would be needed, you're forcing the moral dilemma of an even rarer occurrence with a presumed victim. We don't know if it would come to that. For all I care there might be only some speeding on a rainy road. My car will recommend going slowly for my own sake, but in that moment I care less for me personally and more for avoiding wife's impending death. Actually, I fear that my car will not limit itself to recommending, it will force that on me, because it knows better, because the people behind the said decisions won't be only the engineers trying give their best, but also lawyers doing "mercantile calculation of legal liability", politicians trying to score on public safety through their regulations, and so on!
Even if the problem exists in the early days, I'm pretty sure this is the kind of things that can be dealt with easily later. Those car are already capable of evaluating dangerous situations for others and I don't think that's unreasonable to believe that they will adapt their comportment to conditions and even in some special cases allow for risks taking if it only concerns the one that chose so.
And don't forget that we don't speak about only one company. There will be concurrence as it exists today and if some constructors are so limiting in the behavior of their cars that people die in it when conditions would have allowed to save them otherwise then soon enough someone will come with a car that can deal with that situation and so forth.
Indeed, and that may often be because of taking warranted risks. It bothers me that when making comparisons of driving safety people tend to suffer from absence blindness and discount other important things like the death avoidance cases. Let's say you have a bleeding injured person which requires urgent access to a medical facility. Here the driver can take some risks in order to save a life. Or any number of causes that may warrant risk taking. Now, take away the control from that driver and leave it to an autopilot that may compute the driving parameters in order to satisfy minimum pollution, safety (from the manufacturer's judicial liabilities prospective), and whatnot. Heck, I foresee cases when the autopilot won't even approve any movement due to whatever considerations when there may be passengers in risk of loosing their lives if won't reach somewhere soon enough. For now people can take risks, which may be both good and bad. Don't look only at the bad side.