From #openttdcoop wiki
The TGV concept
Somewhen in a late cargo type game Mucht looked up a website about a french highspeed train. The TGV-concept was born and implemented. Later on the community built some TGV-only maps which were great fun to play. Basically, the usual rules affect the TGV-concept as well as the cargo-concept, but the TGV idea is somewhat different in some aspects:
- [Speed Optimized] The network design is different to the cargo games: the whole network is speed-optimized. The most important thing is building Hubs and stations that do not slow down our trains (except in station areas where nothing else is possible).
- [1x1 mainline] Since we have long trains we have less traffic on our network. We therefore do not necessarily need 2x2 mainlines. A comprehensive network of 1x1 tracks could do the job as well.
- [1 train per route] At the very beginnings it is very important to do a different route for every train. If there are more trains on one and the same route it is very likely that they move very close to each other so one train is always full and others follow them almost empty. If a seperate route is done for each train, this will be very unlikely to happen.
- [Rename station] The stations are renamed. We use identification codes like the international airport codes. So Wrungshaw Woods could be renamed to "WSW", Trestone Heights to "TSH" and so on.
- [Rename trains] A train going from Trestone Heigths to Wrungshaw Woods is beeing renamed to "TSH - WSW". Notice: "T" is lower than "W", so "TSH" stands at the first place.
- [Names are useful] To know if a certain route already exists at a station we now have the train names. Later in the game when a station has more people waiting than can be transported we may surely commit some trains - then named - "TSH - WSW II", "TSH - WSW III" and so on. Always ensure to make the spaces exactly as described here.
- [Design of TGVs] The TGVs themselves always have a certain design. In a very succesfull game we had the Design "Front of train - 5 passenger cars - end of train - 4 mail cars - front of train - 5 passenger cars - end of train". So one TGV was 18 cars long and therefore we needed stations which were at least 9 tiles long. These designs may differ from game to game.