The car is going to make the best effort to minimise impacts to its self, given there's a cliff for it to fall off it's not going to swerve over it. Also as said in a sister comment while you're car full of precious children go over the cliff you can find peace in the knowledge that on average less children have died because there's self driving cars.
Does my car have ethics? If I'm terminal can I tell my car that in a me or someone else situation choose them? What other factors come into play if Im not saying I'm willing? Is it age? Does my car have some sense of WHO is involved and makes a decision based on some arbitrary stat? does it flip a coin?
In theory 32k people live with self driving cars. In theory 32k people live if we all stop driving. If you are give you the choice of writing two programs, one that prevents cars from working at all or one that is going to kill four kids what program are you going to write? There are a lot of things about this that aren't cut and dry at all. Like I said its going to be interesting if we ever get them.