Cities:Skylines does a relevant thing with traffic. Because the granularity of all activity plays out as individual vehicles and pedestrians going from place to

Cities:Skylines does a relevant thing with traffic. Because the granularity of all activity plays out as individual vehicles and pedestrians going from place to place, as you scale up you run into bottlenecks and traffic issues that affect lots of things in the game. Some of it's simply dumb AI bugs, but some is a legitimate requirement for designing road flow (which you can do around the bugs as well if you know they're there). A comparable thing could be done with Civilization-type games if you had something that worked at a low enough level of granularity. Rather than 'because you did this, enjoy 20% more productivity', implement it as something where it depends on underlying factors following a good design.