To be honest I'm not sure if this is already discussed (I did a quick search and pecked through a post on shunting, which is a bit more advanced), but would it be possible to have a setting that causes trains to physically move backwards when reversing, instead of magically flipping in the opposite direction?
The reason that I ask this is that after playing this game on and off for the last 15 years, I find myself trying new things with track layouts. Realistically, with major through stations trains would use short loops to turn themselves around. Of course, when I try this, I often get messages to say that the train is lost, even though two seconds later it's heading in the right direction.
This will probably come back to the shunting post I mentioned earlier though, in that the path-finding algorithm would need to be redesigned to understand what a backwards-moving train can do.
Still, throwing it out there.