Freight train lost its way

[Baldy's Boss]

The Garbourne-Nantham passenger route in the Bundton & Malbourne game shares a little bit of track with a freight line that crosses it.
Somehow,one of the coal trains (its wagons show as circled question marks when empty) took a wrong turn and has been taking the long way around.
What pathfinding glitch caused this and how can I prevent it?
The tracks to the mine have recently been straightened & levelled after a surrounding farm closed.The next train to load often waits in a depot near the loading station.
The shared tracks are nearer to the powerplant.

[Alberth]

After a visit to the power plant, it needed service, and visited the depots at the passenger line just before Garbourne. From there, there is only one way you can go.

Please also tell the train number the next time you refer to a train. It's much easier to find the right train then.

[Baldy's Boss]

After a visit to the power plant, it needed service, and visited the depots at the passenger line just before Garbourne. From there, there is only one way you can go.

Please also tell the train number the next time you refer to a train. It's much easier to find the right train then.

I would have thought that the depot on the way back from the powerplant to the bridge to the junction would have handled such service,but I've now built an additional depot closer to the branch off to the mine than the one near Garbourne.
Now THAT depot may make passenger trains take a wrong turn...but it's on a two-way track,not a one-way track,and the "long way around" is shorter than the one in this case.

I clearly identified the train's appearance and the save was centered on it in the view...

[Alberth]

I would have thought that the depot on the way back from the powerplant to the bridge to the junction would have handled such service,but I've now built an additional depot closer to the branch off to the mine than the one near Garbourne.

Trains start at random moments looking for a depot.

Now THAT depot may make passenger trains take a wrong turn...but it's on a two-way track,not a one-way track,and the "long way around" is shorter than the one in this case.

I always build my junctions such that all trains can go in any direction they like from anywhere. So they may visit "strange" depots, but it doesn't matter, as they can always find a quick way to continue their journey.

I clearly identified the train's appearance and the save was centered on it in the view...

Yes you did, and without it, I would never have found it.
However, it's always nice to confirm we are talking about the same train.

Also, you cannot center the view. The fixed point of the view is at the top left of the screen, so if my screen has a different size than yours it's not in the center.
(you can try it yourself, go to the game options, and pick a small screen size)

[Kevo00]

I always include depot calls in the train's orders. The only discretion I give them is the 'service if required' option. Its the only way to go.

[Baldy's Boss]

so far the cure has caused more tie-ups than the original problem.Working on it.