If I drive my autonomous car to a fancy restaurant with valet parking… How much should I tip? Just kidding there are serious issues to be dealt with.

The Puzzling Calculus of Saving Lives

Let’s say that autonomous cars slash overall traffic-fatality rates by half. So instead of 32,000 drivers, passengers, and pedestrians killed every year, robotic vehicles save 16,000 lives per year and prevent many more injuries.

But here’s the thing. Those 16,000 lives are unlikely to all be the same ones lost in an alternate world without robot cars. When we say autonomous cars can slash fatality rates by half, we really mean that they can save a net total of 16,000 lives a year: for example, saving 20,000 people but still being implicated in 4,000 new deaths.

There’s something troubling about that, as is usually the case when there’s a sacrifice or “trading” of lives.

More: The Ethics of Saving Lives With Autonomous Cars Are Far Murkier Than You Think