Right, and machines could prevent other forms of murder, or help the elderly, or reduce fatal injuries in construction by using robots, etc, etc. It would be cool to get to that stage. Potential != Reality. The reality is that we're far far away from autonomous vehicles operating safely on roads as they are currently designed.

If you want to simply reduce vehicle related deaths, you could address this through various ways like improving road safety/visibility, adding more driver assistance aids. Or heck, design a protocol to disallow cars from starting with a drunk driver or without a seat-belt, etc etc. Maybe people who get into even minor accidents need extra training, etc. etc. There's so many low hanging fruit here..