The geographical distances also favor air traffic over anything on the ground. If the jet engine hadn't come around, North America would have a great high speed rail network today. Ignoring recent events in the middle east and their effect on pricing, even in Japan a flight from Tokyo to Osaka will beat the bullet train fare if you book it a month or more ahead of time. And that's not on a budget airline. Japan gets a lot of praise for its bullet train network. But it's really just one cash cow line (Tokyo-Nagoya-Osaka-Kyoto) and the rest is more often than not half empty. They run it because there is pork barrel politicking and because they can sell the flexibility and immediacy of hopping on a train in a downtown location in this network, on a whim (outside the holiday congestion). Japan is also a centrally organized country where the administrative sub sections (prefectures, cities, etc.) have less say in things. And no local in their right mind would take the shinkansen to go from Kyoto to Osaka. That's a 40min ride or so on the normal trains. The cost to time saving ratio is not good enough.