@Morat: The stations are exclusive cargo or passengers. A station can be upgraded, larger or/and more tracks. Goods can be unloaded to be transferred to another station. Passengers will simply transfer from line to line till he/she reaches the destination. They will also stay inside the train, in case the train goes to more than one station. For example: 1 > 2 > 3. Passenger boarded in station 1 will stay inside the train on station 2 and unboard in station 3 if that its the destination. I notice that because sometimes the train doesn’t fully unload.
The best way to make a line for me is the realistic way: one route going to several towns. Because that saves waiting time, thus reaching more passengers. If the waiting time is long they go by car.
@bafouu: It needs a lot of observing to know how pathfinding works. But in TF people go from one town to another to work for example and then might reach his workplace walking or with a tram or bus. I would need to create parallel lines to know if the problem of CIM 2 is in TF. Like one line going to station 1 > 2 > 3 and one express from 1 to 3.
But since TF doesn’t have comfort and price, the equation is pretty simple: they choose the line that reaches the destination in the fastest way.