I wonder how super high-speed rail (c.f., a train in a vacuum-sealed tube, so no drag) will compete with hypersonic airliners, in about 50 year’s time…
It’s too bad the train system is all monopolies and vested powers. The principle of rail is very efficient, but because there isn’t a highly competitive market the way there is for airlines, it doesn’t translate into much real world gain.
Besides, it’s not like the whole cost of the ticket goes into fuel. A large chunk does. 25% of operating expenses go into fuel (as % of ticket it is less, considering margins). Maintenance, airports, etc., take money too. Even if fuel cost increases by a factor of 10, ticket prices will merely triple. Noone will be driving on $30 gas, but people will still be flying.