Cities Skylines with the traffic manager mod is a great way to spend a whole lot of time if you are bored. It’s surprisingly fun to try to optimize traffic.
And surprisingly frustrating. Why is my city gridlocked? Because only the left most lane of my 6 lane avenue is being used by these 1000 hot dog trucks leaving my port.
As far as I've read, you can solve that problem by just not connecting the parts of your city, in which case the population just pretends everything works.