We have a weekly meeting in Mountain View, CA and every week we see at least one Waymo car (with one or two people inside) driving along the streets. (Since the company’s headquarters are in Mountain View, this is not surprising.) But Mountain View’s streets are easy to navigate compared with the myriad driving environments that self-driving cars face. In March 2018 a driver of a Tesla X was killed when its navigation system failed to recognize a fork in a freeway and crashed the car into a traffic barrier. And this situation still is a lot easier than many others: bad pavements, hard-to-see fences or barriers, etc. While we and millions of other people continue to be excited by the notion of self-driving cars, we believe that it will take a long time for manufacturers to build the needed database of conditions these vehicles face.