[pjerem]

True for local lines of everyday transportation. But actually high speed trains are sustainable, at least in France.

But also they are super expensive.

[geraltofrivia]

Prohibitively expensive! A 1.5h train ride from paris can set me back more than 100EUR some times.

[throw-the-towel]

Just out of curiosity, are these the lines to Bretagne/Normandy? I find the prices on southbound rail lines to be more reasonable, about 60 EUR for a couple hours on the train if you're buying the day before your trip.