This would be time-consuming but great for obsessive players. But: what if each map were plotted on invisible grids or maps accurate to each city, so an ending to a game could tell you where exactly a system shut down? "…due to overcrowding at your station in Hackney." "…your station in Park Slope, Brooklyn." "…your station in Le Marais."
I suspect I'm not the first person to suggest it. But it would be an incredible feature and definitely would keep me playing!