Well spotted! The railway right-of-way and tunnel on the shore of the Inn (incidentally, not far from the hotel I stayed in for one night) belongs to what would have become an even more dramatic mountain railway to South Tyrol, the Reschenscheideckbahn. Work started both during WWI and WWII, but it was never completed and even the short sections with tracks laid never saw regular traffic. However, there is a 2012 study for a railway between Switzerland and Austria along the Inn river, which would follow the old Reschenscheideckbahn alignment for most of its route.

_{*Lunatic*, n.
One whose delusions are out of fashion.}