That's not the math I mean, that's the math of comparing a single railroad with some large airports hubs. Try comparing a sparse Riviera where most activities a

That's not the math I mean, that's the math of comparing a single railroad with some large airports hubs. Try comparing a sparse Riviera where most activities are remote or local, so at a very short range, typically with cars on 20km radius, and some other small activities are made by STOL witch do not demand much of airport, just a surface, a grass one is not the best but still work, the taxiways just a path to a space where you can park not differently than a car parking lot. The non-local part can be served by water (when possible) or by rails from a small hub to another depending on the territory. In such setup you still have commercial transports but people ones are FAR different than now, so the relative infra is far different. Since roads are mostly for short range activities there are no large viaduct, bridges, tunnels because there are no highways, no big cities to serve and so on. There are rail stations, harbors, sure, but FAR little than the actual large ones because there is no need to concentrate the network. In IT terms: did you remember the evolution from mainframe to clusters? Well does clusters demand more resources than mainframes? Are them concentrated? Networks in general have a common set of properties from roads to LAN/MAN/WAN passing through biological "networks", try the math in such terms.