[alephnerd]

I take it you've never been to the US.

Sofia to Bucharest is approx 400km.

San Francisco to Los Angeles is 600km.

Sofia to Bucharest is largely flat.

San Francisco to Los Angeles requires building rail lines in multiple mountain ranges that rival the Carpathians.

Imagine having to build a 600km high speed railway line through 3 mountain ranges the size and height of the Carpathians, oh and almost nobody lives in between the two metros.

It does not make financial sense.

[noirbot]

Additionally, trying to buy any of the land in between, let alone get environmental damage clearances for building all those tunnels and bridges is probably borderline impossible. Most US rail was built in the era where we were actively taking the land by force and just demolishing nature in the pursuit of progress. It's not clear to me that we could build something like the highway system or a major new rail system in a way that wouldn't be massively detrimental to the environment or the communities along the routes without also making it insanely expensive/inefficient.