[dredmorbius]

OTOH, there's a lot of stuff that is far more feasibly moved on the Earth's surface rather than in flight. So some sort of surface-level infrastructure will be required: highways, railroads, canals, rivers, oceans.

Some of those are amenable to high-speed variants, some less so. And once you've established transport corridors, much of the hard part (rights-of-way acquisition) is accomplished, so that adding a high-speed route becomes far more tractable.

For the most part, actual construction costs are fairly modest, modulo bridges and tunnels, both of which can of course be quite expensive.

[rickydroll]

Good points. I think that running rail parallel to highways, especially if the rail can travel twice to three times as fast as road traffic, is a good plan.

I think increasing the viability of travel between smaller airports is a good thing for those times when you don't want to spend a lot of time traveling or waiting for a transit vehicle. If the equivalent of micromobility air travel comes to fruition, you'll see two- or three-person vehicles that get up and go when someone wants a ride. Another benefit could be the airport-to-airport delivery of packages with different-sized drone craft and autonomous navigation.

#IFoundMyFlyingCar

[bluGill]

Flying still require an airport which means you need a fair amount of distance. Sure some make short flights today but they have made their life center around flying those short flights they can't accept houses or joins that are not close to an airport. Most wouldn't accept that compromise in their life.