Trains don't pass

[railduffer]

OK I've had it. Can anyone help me get trains to pass on MY new route? The two trains (40 cars) show the proper paths through the passing tracks (Main & Passing). When I start the scenario, the path (switch to the Main) for the driven train changes to the passing track. I can see this through the map. The switch for the AI does not change, so a collision.
I set this up with just two locomotives at opposite ends and close to the passing tracks, and it works as it should.
There seems to be something wrong. Can any one help?

[Chacal]

Put some waypoints along the way to force the dispatcher to set the correct route.

[railduffer]

I think I found the problem. It seemed the switch on one end of the passing siding was the problem. I had laid the switch on a curve. The program placed it's own automatic switch throw. It seemed the switch would always throw to the passing line when I started the scenario. After trying everything I could think of including chacal's suggestion, I changed the throw to manual. Then I changed back to automatic. For whatever reason it now works.