There is a fly in the ointment when we speak of a viable future. I shall explain. First, let's accept that two things constitute the bare bones of any city.

Everything in it -- residences to parks to businesses to everything else you can imagine. Education, commerce, eateries, health, recreation, homes, entertainment, sports, spirituality. Imagine everything melded to create one of the novel creations I call cybercommunities.

transportation is the minimum needed to conveniently connect everything in it. So if everything is melded into car-free communities these can be connected by almost cost-free public transportation along the lines of hyperloop.

Cars will not be needed

In this system, there is no need for Cars. The communities themselves are no more than a mile from side to side and no more than four levels high. No cars would be within them. They would be completely walkable. In this world, transportation under or above ground would be unnecessary. An evolution of the idea of hyperloop would link communities in an environment that would be nearly traffic free.

We need to create a sustainable world

We would phase out our currently untenable car-oil economy, Oil will run out and it is a highly unstable basis for a sustainable world. Cars will be used more for recreation and going long distances than for commuting. They will be a choice, not a necessity.

The fallacy of self-driving cars

The smart money now is on the idea that we will have a world of self-driving cars. Already the partisans of these wonders are telling us that they will integrate seamlessly into a transportation mix of the same old same old and allow us to retain everything in the same old way.

The driverless car tells us that the notion of the car we drove because we loved freedom is receding.

In a time of congestion, commuting and traffic jams, the car becomes how we get there. Getting there is ever more time-consuming and expensive.

We should be able to walk freely even in areas in areas of density. We should be able to get from one community to another cheaply and reliably. We never voted for driverless cars. My guess is that their relevance will decline as the logic of cybercommunities takes hold.