With self-driving cars, you also need to consider the kind of people who might be driving them manually. Drunk, sleepy, prone to road rage, distracted by noisy kids in the car, thinking about their financial or relationship problems... there's a terrible amount of death and shattered lives to consider there.

If I remember right, during the height of the most recent Iraq war, a U.S. soldier had a higher probability of being killed in a traffic accident while in the United States than being killed while actively deployed in Iraq.

If a (so-called) self-driving car screws up and kills some people, it's headline news everywhere. If Joe Blow downs five shots of scotch after being chewed out by his boss and crashes into a carload of kids, it barely makes the local news.