There was a good segment on NPR yesterday on how self driving cars will reinvent parking lots . Speculators should be buying city center parking lots now, as they will become very valuable real estate soon. Two things strike me, in general, about the self driving car discussions: We have still not internalized that advances in the software are exponential , not linear. With new cars being closer to "software with wheels" and the ability to download updates on demand, that exponential progress will now become apparent. Of course, regulators will be slower, but I feel like the 10-15 years before adoption is pessimistic. Perhaps more interestingly, where is the discussion of self driving public transit? And, in particular light-rail systems and/or subways. What if we used a bit of imagination, and thought about the combination of self driving technology and no more rails? Think about how restrictive, and expensive, rails are. What purpose do they serve in a moder