Faster trains make longer distances competitive with air travel. Assuming a similar price per mile, the cutoff is T * deltaV where T is the extra time to travel to and from the airport and get through security and deltaV is the difference in speed. Assuming 3 hours and 250mph (500 - 250) the cutover is 750 miles.
Reality is less simple as price varies as well. In Europe the cutover (in time and price) seems about 200 miles [1] although the CO2 emissions are up to 30x higher by air. Of course speeds are lower, maybe 150mph which would suggest a 450mi cutoff.
Reality is less simple as price varies as well. In Europe the cutover (in time and price) seems about 200 miles [1] although the CO2 emissions are up to 30x higher by air. Of course speeds are lower, maybe 150mph which would suggest a 450mi cutoff.
[1] https://m.dw.com/en/trains-vs-planes-whats-the-real-cost-of-...