Recreation Steps.
Make a train line with multiple paths.
Park 1 train in one of the paths (maybe vertical only?)
Wait long enough, when a train comes into the station it will miss the exist of an available line and go far enough into the parked area and block everything up. It appears that the train is missing it's turn somehow. The train shown here in the stuck position is a bypass train that is just routing through the station, no stops here. The parked train is a train that is sitting at the given station and is not moving or set to move. I don't believe this has ever happened when I'm in the are but when I go a long ways off and the main base isn't displayed on the screen. When this occurs (in my setup) it essentially backups up my entire network since all trains go through this station. I have attached a screen shot that shows the stuck position and have a save if you want it where the trains are stuck.
From what I understand no train should take the route where the parked train is sitting. I have had this occur when the parked train has a route of just the station it is at and running as well as not running. Also occur when the parked train has no route in it.
In the example shot this occurred after I was coming back from a biter cleansing excursion deep into biter territory. When I came back it was stuck.
