DynamicSpirit
Established Member
Flying doesn't have as much fixed infrastructure to pay for. Therefore, as distance is further, the cost of rail infrastructure is greater, while the cost of air infrastructure diminishes.
Add to that that most aircraft fly at something like 500+ mph - whereas very few trains average more than 100mph. That means that you can transport people maybe 5 times the distance in the same time. Since most of your costs (staff, rents, leasing, etc.) depend mainly on how long you are using the infrastructure and vehicles for, not how far the vehicles travel in that time, that means that faster speeds equate to more efficient infrastructure use.
Another factor is airlines don't really have a turn-up-and-go operating model, and they aren't expected to run planes half-empty in order to meet social obligations to communities - so they can focus entirely on commercial routes, and if they don't fill up their planes, they can quickly stop operating.
Then of course there is the tax regime, which is highly favourable o airlines, allowing them to do huge damage to the environment without ever worrying about paying for most of that damage.