There is an element of busywork too: local officials are always elected by promising change, they have to be seen doing something. So on odd years they put in something, and in even years they take it out...
[1] https://upload.wikimedia.org/wikipedia/commons/thumb/7/72/NY...
It's more like the area from New York to Boston
I'm sensing a bit of a Catch-22 in this hypothetical: How would the success of Uber-like services been impacted if 80% of the population no longer needed cars?
They wouldn't need it, but I bet that majority would still want it.
* car sales do not drop, they oscillate depending on various governments subventions;
* vehicle fleet keeps rising (albeit slowly because the market is saturated);
* car owning per household has always been and is still on the rise (despite household size constantly decreasing);
* the distance travelled with cars keeps rising as well.
And visually, the amount of cars parked in the streets and along roadsides becomes insane. You already thought it was full 30 years ago, but now it is fuller.
Oh, and the cars become bigger every year. Not American-big, but still, on the way to it. For example, pickup trucks never took off in the French countryside in the last 50 years, not a single bit; but for a couple of years, it has started :-/
1) "suburbia" is now a thing in Europe too. Regular people cannot afford to live in city centres, they are the preserve of the wealthy. As population grows, more and more people are pushed further out, and they adopt suburbanization: big malls that cannot be reached if not by car, semi-detached houses in gated communities, etc etc. That's a lifestyle built for cars.
2) People will buy what manufacturers will sell. In a global market, car models are increasingly built with more than one country in mind. Inevitably, US tastes loom large.
3) The Hollywood influence cannot be underestimated.
I'm aware of those factors, but I still think we took a wrong turn. Maybe not in the US due to the population sparsity and sprawl, but in Spain and many other European countries, if we could connect every town or city of more than 10K people by either rail, light rail or tram (instead of having spent billions on highways), that would cover 80% of the population. A large majority wouldn't need a car, and could instead use Uber-like services for the last mile. Pollution and emissions would be much less of a problem, and quality of life in cities much better.
But that's what happens with gradient descent, it can lead you to a local minimum...