I have been working on a new train network AI. Along the way, I stumbled on this creation that has entertained me and I think is worthy of being published. It's called FastPTPAI.
As the name implies, it is fast and builds PTP routes. It is very simple, and all it does is build more routes. It does not manage them. It is surprisingly competitive, however.
Pink - FastPTPAI
Blue - Convoy
Red - NoCAB
As with any of my AIs, I am welcome to bug/crash reports, suggestions, etc.
In the future, I hope to add support for multiple trains per route and ro-ro stations. I also need to add slow AI mode. These things should be available for it soon, I just need more time

The .tar download for this AI is below, and it will also be available on bananas.
EDIT: Added attachment player color information