Unfortunately there is no feedback thread for the Niddertalbahn. That's why I'm posting it here. At many stations on the Niddertalbahn there are no passengers at all. I can't say exactly which train stations they are because I don't write everything down during the game, but Stockheim is definitely deserted. It's boring to travel most of the route with an almost empty train. Really very boring...
For some time now stations in TSW have been using curves for density of passengers (depending on time of day). It may be that the curves for some of the stations there are set too low or incorrectly. The problem with missing passengers on platforms can be fixed on the route level and not in core. For example the recent update of West Somerset made the platform of (I think) Dunster populated with waiting passengers, as previously it was completely empty through the day and people were only alighting there.
I have found the reason why Stockheim Station is deserted. Take a look at the back of Stockheim Station building where the passenger spawning point is. They are all stuck there bumping into each other unable to move which results in there being no passengers on the platforms. I happened to stumble across it recently.
