ok, just a general questions: About how many train lines and stations are you supposed to have? Im currently a bit over 100k people and i have 8 freight stations and 7 normal train stations, an extensive rail network with lots of bypasses at the stations but there are just sooo many trains that everything is clogged to the point where nothing moves anymore. there are just too many trains!!! I have one main passenger line which goes round the cities stations with 2 supporting lines (1 airport, 1 industrial area).
I dont know how i can influence the amount of cargo trains or passenger trains...
Basically, there are four types of train. Internal and External, Passenger and Freight.
Internal Passenger trains only run on the routes you specify, just like Metro lines.
External Passenger trains arrive from the map edge and call at a station, deposit tourists, then leave.
Internal Freight trains spawn automatically at your freight stations, and travel to another one to transfer goods between resources, industry and commercial.
External Freight trains arrive from the map edge and call at multiple freight stations, picking up and delivering goods and resources.
The key thing is to avoid putting all of these types of train on one set of tracks. External passenger trains in particular can really clog things up, as they send a train to each of your stations, each with a handful of people.
For a city of your size, it's time to segregate. Have two separate networks for your internal passenger and freight trains. Handle External trains by building transfer stations - ie. two stations facing each other. For 100K you can get away with a two of these for freight and one for passengers.