https://stellwerke.info/ https://stellwerke.info/ has a good overview, and I think by now it's also quite comprehensive. If you look at the map, filter for act

https://stellwerke.info/ https://stellwerke.info/ has a good overview, and I think by now it's also quite comprehensive. If you look at the map, filter for active signal boxes only and also remove "Elektrische Stellwerke" from the default filter, you might be able to discover whether the are any other mechanical or electro-mechanical signal boxes left on any of the main intercity routes. (And since you mentioned Berchtesgaden: It looks like that whole line was switched to ESTW-operation (for non-Germans: computer-based interlockings) in November last year.