Modern logistics play a big role in modern commerce and warfare.
The first thing is to improve railroads:
- railroad stations should give adjacency bonuses to all FIMS quarters - farmer quarters can bring more fertilizers, market quarters can bring more goods to sell, and research quarters can... bring more material to research? Anyway, it would make sense that railroad stations improve all types of yield, not only industry. Shouldn't break the game as they are allowed one per territory.

- make railroad infrastructure. Harbors have some huge infrastructures that allow them to feed pretty big cities and generate much money from trade. Why there's no such infrastructure for railroad? I can suggest at least 2 branches - one increases FIMS adjacency yield, and one grants bonus Money for land trade routes.

- Sometimes I really struggle with building railroads as I miss territories and my stations don't connect. We need a tool highlighting roads and their type, maybe as part of a trade route screen, maybe adding a new one dedicated to logistics, as roads can be used not only for trade, but also for rapid repositioning of armies. Also that lens should highlight whether territories have Harbor/Railroad station/Airport.