The Oct 20 patch notes were pretty terse:
Lines can now cross. It's still best to avoid it as your trains move slower when they have to cross other lines.
In the old version, it was often difficult to tell whether a particular route would result in lines crossing, but because it was illegal to make them cross, you could fiddle around until you got a route that didn't cross.
Now it seems like there's no visual indication of whether a particular arrangement results in lines crossing. This seems like a bit of a bummer. Even if the old version was sometimes frustrating, it was always clear what was going on. Now it seems I'm left to wonder if I'm being inefficient or not. Or is there a visual indicator I'm missing?