This is yet another report sent to Rail Simulation today. In the last paragraph I illustrate a common AI problem that has been around for the life of the product. If you send an AI train through an unsignaled crowded yard, with one logic path through, it is likely that the AI will hit a train. AI chooses the most direct path through the yard and if a train is on that path - tough. Will try to find some biscuits and jam so I can rest.

Picture Below
Castle Rock Route
Service 3 is AI going to Larkspur priority=International
The other red arrow is the back of AI Service 7 consist. It is also going to Larkspur but a different place. Priority = Light Engine
Both start at the same time. Service 3 is a steam service and Service 7 is diesel.
Service 7 gains speed first and extends the interval to about a mile.
Service 3 is also moving but initially slowly.
Suddenly both trains instantly stop defying the laws of nature and begin to slowly creep forward.
Is this some poor proximity logic?

Prior to the above scenario Service 7 had no destination in the Driver flyout so it did not move.
In this case Service 3 started and despite a clear alternative path it rammed directly into the back of Service 7.
This may be a error in the AI logic!