The Jetsons had them in the 1960s. They were the defining element of “Knight Rider” in the 1980s: cars that drive themselves. Self-driving cars appear in countless science fiction movies. By Hollywood standards, they are so normal we don’t even notice them.

But in real life, they still don’t exist. So what if they were real? What if you could buy one today?

When I was 18, I lost a close friend to a car accident. His friend had taken his father’s brand-new Audi Quattro for a spin, and he took my friend along for the ride. On an icy road, the driver lost control of the car and collided head-on with a truck. Both he and my friend were declared dead at the scene.

This was not an isolated occurrence. Roughly a year ago, my lab manager succumbed to a traffic accident. A distracted driver hit her Prius at more than 50 miles an hour from the side while she was driving cautiously through an intersection.