These are two pretty unrelated issues, and it is a fallacy to compare the two in this context. It's not unlikely that the majority of transit in the western wil

These are two pretty unrelated issues, and it is a fallacy to compare the two in this context. It's not unlikely that the majority of transit in the western will be automated in the next century or two. The technology to filter and clean water has existed since the Roman era, but its implementation is highly dependent on political and economic factors (fun fact: western civilization didn't match the Romans' quality of water engineering until the mid-19th century). The technology for automated cars could well exist in 150 years, and its implementation depends on the cycles of industrial production and consumption. It's likely that much of the western world will have automated transit in 150 years, because everyone will eventually get rid of their 2015 toyota for a model 2077 automated Tesla-google car.