[overkalix]

Very successful? AVE routes, including the BCN-MAD one, are not financially sustainable. Spanish and European taxpayer money devoted to the comfort of businessmen and bureaucrats and the profits of contractors while metropolitan lines fall apart and receive little to no investment.

[djrobstep]

Most infrastructure like this is not "financially sustainable" in a narrow sense because most of the positive externalities aren't capturable. It's nonetheless a good idea (although we certainly need to figure out how to do these things cheaper and less corruptly).

The environmental benefits alone must be considerable as the route has replaced more than half of the air traffic iirc.