It could probably be done today with richer sensors on the car than just visual and with "smart" roads outfitted with specialized symbols and transponders to gu

It could probably be done today with richer sensors on the car than just visual and with "smart" roads outfitted with specialized symbols and transponders to guide the car. Pure self drive like humans do requires a cognitive model of cause and effect and the nature of the world being navigated, not just pattern recognition and prediction. Enormous advances in predictive and pattern recognizing AI have been made in recent years, but these things still don't "understand" anything. I put understand in quotes because I still don't think we understand understanding. The mistake of those who have bet the farm of self drive (Musk/Tesla being chief among them) is to jump the gun and think that the AI advances of the last decade have made it just a problem of scaling a technology. It's not. It's still a fundamental invention problem, not a scaling problem, but what we have is good enough to fool us into thinking we can get there. Musk's other big venture SpaceX can successfully build and scale rockets to send humans to the Moon and Mars. That's because that, unlike full self drive, is just a matter of scaling already thoroughly understood physics. We know exactly how to build such things. We just haven't done it yet (beyond Apollo).