The contiguous United States has a higher population density than Spain, which has a great high speed rail system. Metropolitan France is not much more denser than that as well.
Chicago to nyc is currently a 20 hour train or a two hour flight. High speed rail would be a massive expense to get a best case scenario of maybe 4 hours. The flight just makes more sense for people. Both cities have good rail options for inter city transport, or even out to suburbs.
The contiguous United States has a higher population density than Spain, which has a great high speed rail system. Metropolitan France is not much more denser than that as well.
Chicago to nyc is currently a 20 hour train or a two hour flight. High speed rail would be a massive expense to get a best case scenario of maybe 4 hours. The flight just makes more sense for people. Both cities have good rail options for inter city transport, or even out to suburbs.