This is supposed to be a low speed service - 30km/h - so they could meander around mountains to a large extent. Am I misreading that this is supposed to be entirely underground?
There's plenty of space underground and sure it's a higher one-time cost, but the conserving the surface for people is probably worthwhile.
I wonder about induced demand. Presumably total freight volumes will not change drastically in response to the availability of this new system, in which case one could expect road traffic reductions to be stable.
The quieter roads may well induce more personal transportation, but then with Switzerland’s already very good passenger rail connections, maybe not.
Seems like a win all round.