Comment 38 for bug 1535115

I don't see a second carrier building helping. all roads had a second carrier, but they were jammed anyway.

a study showed that an insoluble traffic jam is created when flows of wares from three different directions intersect. There can be ways to prevent that by coding, for example by recognizing that all carriers around a flag are standing still. but adding carriers won't do much.

Also, I hope you don't take it badly if I decline trying concentric rings again to check the fix: it toook 50 hours of gameplay to reach that point last time, and given the random nature of that kind of jams, it may not even help.