Train re-routing in blocked 4way intersection possible?

[Zaz]

In the picture we see a non-interfering 4-way section.
In the top-right corner we see a train, its destination is the lower left corner.

However there is an obstruction (In this case a small engine) blocking the path.

The train will always run up to the red light, and then stop, blocking the way for any other train wanting to take a right turn.
Is there any way to force this train to take the right turn here?

[Manar]

I think it will choose a green light if you make the signals it has to choose from two-way.
Ofcourse, this can cause some of your trains to get really lost in your network.

[RiTi]

Use Way-Points and put these in the orderlist of the train. The Way-Points give you to possibility to force the train to take a specific route.

[Zaz]

Waypoints won't work, since the normal way for the train to go would be the way it is trying to go in the picture above.

What I want is that if the intersection is blocked (as it is in the picture) the train should instead choose to turn right and try to find an alternative route to its goal.

[Cougar]

What Manar said should work. The signals after a split need to be two way signals and then the train will choose the open route... Try it..

[bobingabout]

dousn't that encorage trains to get lost?

[Manar]

I suppose if you're using lots of full cloverleafs like that, it might turn out alright. But you're more likely to run into problems.
You also need to hope that the obstruction blocks just the right squares, which is a bit unlikely if you're talking about breakdowns.

[sc79]

If you have a viable alternative route when a train finds a red signal, it should use it, depending on the pathfinder you're using. However, unless its of a similar design and distance, the train is simply more likely to wait (though you can edit the settings that affect this for YAPF), which is probably not a bad thing anyway, as 99% of the time a detour would likely cost more time than simply waiting for the signal.