A bird's eye view of a city is ideal for budding urban planners, but deep down I suspect many of us want to explore our creations first-hand. Thanks to one of the many Cities: Skylines [official site] modders, you can do just that with the first-person camera mod.
If you're interested in giving this a go, forewarned is forearmed: it's advised that you also install the Dynamic Resolution and HideUI mods. At present this first-person camera mod doesn't quite simulate controlling a vehicle or pedestrian, either: it's more like you're flying a small drone over the city.
Building and managing a smoothly functioning city isn't exactly the easiest job in the world, and in the game. It's for this reason that Sim City allowed players to summon natural disasters (and, depending on the version you're playing, unnatural disasters): a bit of visceral destruction helps blow off steam. This mod makes for a pleasant alternative for those who'd rather perambulate about their creations than destroy something beautiful.
The game isn't optimised for close-up inspection, of course, and the closer you get to the action the more likely you are to see oddities in traffic and pedestrian behaviour. But who knows, perhaps seeing problems first-hand will help in working out how to improve traffic flow and manage congestion. Or you could just derive amusement from the seemingly inexplicable behaviour of AI-driven entities; I know I do.
If you'd like to take your Cities: Skyline modding adventures further than this, there's what looks like a nifty list of recommendations here on NeoGAF.