Nissan is promising to bring self-driving cars to market by 2020. I am very excited for self-driving cars; I think if Nissan and Google do them right, laws will soon be in place to make self-driving cars the norm, the way seat belt laws proliferated once statistics proved their value.

But I think there's something more to self-driving cars than just safety and easing congestion; I think self-driving cars will make the ownership of cars less of a necessity in cities. Why would you need your own car if there was a fleet of self-driving taxis waiting to take you safely to your destination? For better or for worse, efficient and reliable robot taxis will probably put human taxi drivers out of business at some point in the next few decades, the way the internet has sheared off jobs in countless industries over the last few years.

I think an entire network of automobiles communicating with each other will depersonalize the ownership of cars and could make them feel more like a public trust. Will Americans love their cars as much as they do now when they just get in, say an address, and sit there until they arrive at their destination? I think some of the character of automobiles, the way that Americans feel cars are extensions of their own personalities, will fade. I think maybe that's for the best.