Hmm, didn't know it had co-operative multiplayer.
Since it's not a competition - sort of like in Melbourne when there was National Express and Connex - I am happy to give tips on rail construction and in particular signalling.

I nominate to run the server with the following settings:
Map size: 1024x1024
Climate: Temperate
Start Date: 1970 (Electrified Railways available)
Patches Enabled:
- Vehicles Never Expire
- Show Reserved Tracks for Path Based Signalling
- 'Realistic' Vehicle Acceleration model.