I would like to suggest a couple of modification to the game to make the freight system a little more sensible.
Currently not only the basic resources: coal, iron ore, oil and timber are generated on the map but also their appropriate processing plant are also generated randomly on the map at the same time. This is not logical, it’s not how the real world works. The basic resources are placed by nature, the processing plants are placed by people!
So wouldn’t it be better if just the basic resources were generated on the map. Then the player would place the appropriate processing plants in places of their choice as part of the game?
Then to take the next logical step both the natural resource extraction facilities (when they are producing), and the processing plants should require workers, their numbers increasing in proportion to level of production. The workers would then need transport.