Priority-restrain from taking path thru industry?

On my routes a priority-2 (freight) train will detour through an industry when the track is marked priority-1. Marking the mainline at the industry both priority 1 & 2 and the train continues to use the industry track which is marked as priority-3.

I did not expect the priority 3 setting to reject the train since it has a slightly different rule set.

A passenger train (priority-1) does not take the industry shortcut and stays on the assigned priority track. I do not see a bug here but perhaps a re-evaluation of the priority system to insure that only prioity3 trains can use the marked industry track.

I wouldn't use priority markers here. The AI will take the shortest path between two points even if that shortest path is through the slowest route. What determines this is the distance? A switch diverging off can make the trip shorter through the industry instead of the quicker mainline track. The priority markers won't work in this case because the AI even with priority 1 will take the priority 3 track, but not the other way around. Why the passenger train doesn't do that? You're lucky so far so go play the lottery!

If I were you, I would use simple track marks. Put the marks on the mainline and direct all trains not servicing the industry to take the route marked with the track marks. The little extra work will make your life a lot easier.

Marking a track Priority 1 does not stop trains of Priority 2 and 3 from using it. It only forces trains of Priority 1 to use the track (unless it is blocked).

In your example of the priority 1 train ignoring the priority 1 path, two possibilities come to mind.
1. The priority 1 path is blocked (another consists, a locked switch, broken track).
2. The priority 1 train has been given a conflicting Drive To order which overrides the priority settings.

Thanks - TrackMarks it will be......

Isn't there a difference here between using "Navigate to..." and "Drive to..." or did that go away? I thought one of those options weighed track priorities a little heavier in it's "shortest" determination?

Or am I misunderstanding something I read a while ago?

The difference is explained in the first of these 2 blogs on AI behavior.
https://forums.auran.com/trainz/entry.php?951-Using-the-Trainz-AI-in-sessions-Part-1
https://forums.auran.com/trainz/entry.php?958-Using-the-Trainz-AI-in-sessions-Part-2

Peter