A new version has been released, where I redesigned cost scaling completely. This version will remain as an alternative.

https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=2805165537

Visual changes are definitely out of scope this mod. Regarding only counting the used tracks - sounds logical, but in the end I don't think it will add much to the gameplay for the amount of effort it needs to be implemented. Tracks are dirt-cheap compared to everything else, so adding this kind of differentiation will not have much visible effect in most games, IMO.

The original motivation for the mod was the fact that I can build lots of excessive infrastructure in mid-game, like insane bridges and tunnels, without too much thought. Maintenance costs become joke later, so this adds additional money sink to make mid-late game a little bit more challenging (hopefully), as well as a bit more immersive as you see infrastructure costs being at comparable levels to vehicle costs even in later game.

I feel like only used pieces of infastructure should have increasing cost since if its nused that could be considered abandoned and having deteriorating track on the map could add alot of nice extra detail

Wow very nice! I always looking for some mods about spending money.
I hope so you will make something more about spending in future. :*

awesome