I ultimately gave up on skylines because I kind of broke my city and it got really tiresome to try and repair or start over. Tried a few mods to greater or lesser success but they just revealed other flaws. For example, whichever mod allowed for more realistic population densities; you'd have 700 families in a residential building or w/e, but no clue where they work, and likewise in the reverse. I somehow can't click on an office tower and see what the geographic distribution of occupants is, only those that are currently commuting. I'd also get strange issues like some of my subway lines inexplicably being totally vacant no matter what I did. It's also an incredibly inefficient game to run.
Most of the agents in a building are not actually doing anything most of the time; the game has a strict limit of 16,383 moving and 32,767 parked vehicles. These numbers were chosen so that the minimum spec computer at time of the initial release would get 60fps. Mods can increase this somewhat, which is usually safe because our computers have gotten faster.
The built–in tools are also somewhat hit and miss, and that is partly driven by what information the game holds on to and what it throws away for increased efficiency. Agents know their destination and chosen route, but they don’t remember where they are coming from. Thus, when you click on a building to show the associated traffic routes it can only show routes with that building as a destination.
The exception is service buildings like fire or police; each one supplies a fixed number of vehicles, and in theory the tool could show what all of those vehicles are doing. It still just shows the routes that end at the building though, so you end up seeing just those service vehicles that are going home and people who are going to work at the service building. In principle, mods can fix some of these oversights. I use one that shows what each service vehicle is doing, for example. Another mod that I really like allows you to select a stop on a mass–transit vehicle route (a bus stop or a metro station or a ferry station or whatever) and see where everyone who is currently waiting at that stop is going. Very useful.
That said, I think Cities: Skylines is the best SimCity we’ve ever had. It is everything that SimCity 2013 should have been. I recommend it to everyone, but especially people who ever enjoyed a game of SimCity, or has enjoyed any city builder of any stripe, or who think that games are only for children.
The realistic density mod is one of the most game changing and I wouldn’t recommend it until you’re very familiar with the game and how it works/models.
Most of the population just is not simulated, I think. So the game can't show you that information.
I had a similar reaction, after a city of mine completely broke because of simulation errors I gave up on it for a while. Then revisited a bit later to write an article about all the dlcs. It felt a lot more stable then, but that might be because I did not test the edge cases again.
