Why? Mass transit is an industrial age solution to the congestion problem, when we couldn't plan for demand in real-time. Mass transit means that there need to

Why? Mass transit is an industrial age solution to the congestion problem, when we couldn't plan for demand in real-time. Mass transit means that there need to be a lot of people who want to go from the same place, to the same place, at the same time. This is never true, so you have to relax the assumptions: they aren't coming from the same place, so force them all to walk to a stop. They aren't going to the same place, so force them to walk from a stop. They don't want to go at the same time, so force them to wait for the next bus/train. If you're in a very dense city at a busy time of day, this isn't too bad, you don't have to walk too far, and you don't have to wait too long. Otherwise, it's not possible to get enough people that want to make the same trip at the same time without making people walk long distances or wait a long time. On demand Lyft Line style routing, automatically driven, with variable sized vehicles depending on demand in the area, is going to completely replace mass transit in twenty years. The cost will be the same, and the travel time will be half or less.