So I don't know how it is with European lines and trains because I never play them, but as for U.S. freight I'd love to see more variation in signaling. For example, in "Powering America Part 2" you get a Medium Approach signal (if I remember correctly), then once you get to the summit the signal shows to stop to allow a train coming the other way to pass. I've memorized all of CSX's signals (Clear, Medium Approach Slow, Advance Approach, Restricting, etcetera), so I'd love to see that implemented more in the U.S. freight lines. I'm even learning Union Pacific's signals for Cane Creek in the hopes that I can use that knowledge when it releases. Anyway, I think that would be a pretty cool and authentic addition to the U.S. freight lines.