Strange AI Paths

[FLWBStrainman]

I have been running my Indiana Rail Road route recently, and I've noticed that AI trains behave strangely at one particular siding. It is a stretch of double-track mainline. At the north end, there is a left diverge switch, with corresponding absolute signal. There are absolute signals protecting each line behind the junction. At the south end, the switch is a right diverge. It is an unusual switch because it is on a curve, so it could be considered to be a Y. It also has adequate signal protection.

Now, the problem...
The southbound AI trains always seem to prefer the #2 main, which, for southbounds, is the diverging track. It has a reduced speed limit of 10 MPH. This doesn't make much sense. Could this be a signaling error?

 

[Dermmy]

Trainz under AI control will always take the shortest route if the shortest route is available. The only AI consideration is physical distance, signalling and speed restrictions are irrelevant to the 'which route' calculation and the difference in length can be miniscule. Even if your track layout is proto I would re-signal it so the short route is the main, that way trains will hold the main if possible and take the siding only if the main is occupied. Other solutions may be to allocate train and track priorities, use direction markers, or use 'drive via trackmark' commands, but then some trains will always take the siding....

Andy