I guarantee you that it's NOT used in more formal registers, now that you showed me that Wikipedia article maybe I already read the term on some history book, but no, it's never used now.
Looking it up a little it appeared to have been used initially, but it was probably already obsolete by the end of the nineteenth century.
I'm trying to recall where my memories come from. Might be this: https://it.m.wikipedia.org/wiki/Strade_Ferrate_Sarde . Apparently there were called like that till the late '80s, it is possible my family might have mentioned them even after that.
I guarantee you that it's NOT used in more formal registers, now that you showed me that Wikipedia article maybe I already read the term on some history book, but no, it's never used now.
Looking it up a little it appeared to have been used initially, but it was probably already obsolete by the end of the nineteenth century.
Thank you for making me learn something anyhow xD