Say it's 2050 and though the roads are not as full as now, people make do with cars if they can afford it. Most others stay where they are because there is no way to cheaply go anywhere at all.
Construction has not changed but more and more of sprawl has been abandoned and more large vacated highway spaces have been chopped up into efficiency apartments.
The schools are now moving toward thirtieth worst in the world and higher education is for the wealthy only with a receding number of scholarships based on merit.
I could go on but let me simply state my theory for the umpteenth time:
We need a totally new theory of settlements based somewhat on Alexander's "Pattern Language" modified to insist that human settlements be car free, that we live in numbers of about 5-10K in a square mile, that all elements of a city be within a single community, and so forth.
We need to generate huge new industries based on creating the modular components of the new construction. We need eco matrix production so that each community can be sustainable in itself, recycling everything, generating its own energy, etc. We need to create local governance that is made up of residents who live and work in these cyber-communities.
I am not saying we cannot adapt what we have now. But we need a model to be built and no one has even drawn it yet.
If this became our plan we would have a vibrant economy and smart solutions and a good future. If we ignore the reality we mark time until we cannot even dream of it.
We will not get the change we need until we are willing to articulate what it is.