Cities: Skylines isn’t the most realistic simulator in the world. In fact, it’s quite easy to trick the game into some nonsensical outcomes – for example, just building elevated pedestrian paths literally everywhere in your city, connecting to every single intersection, confuses the citizens enough that they walk everywhere instead of using faster means. Despite the existence of day/night cycles there’s also no simulation of rush hours, and cars can never get into accidents. Roads instantly build or upgrade themselves, meaning there’s no need to redirect traffic during an upgrade effort. Your citizens seem to have infinite money, too, regardless of social status. The only major disrupting force is the Natural Disasters DLC, which is probably the worst DLC of them all and I don’t think many people even play with it on. The game is a considerably reduced-stress environment in which you develop your city in, but at the same time this means that rather than focusing on improving quality of life for your citizens, you’re spending the majority of your time problem-solving for the many, many cars that exist in it. As the very first thing you can place in your city, roads take precedence over just about everything else in the game.
In Cities: Skylines, and just about any city-building game, buildings can only be built alongside a road, and must maintain road access to be functional. The only network that generates tiles for anything to be built on is the road network, and literally everything in the game uses roads to connect. The emergency services’ range is defined by how far their road access allows them, same with education. Got a supply depot for your industrial area? You need lorries to drive the cargo from the station to the building, even if they’re right next to each other. Managing your road network is the backbone of the game’s experience, and also occupies the majority of your city’s space. In addition, large roads with heavy traffic generate a lot of noise pollution, meaning you have much less space to build residential than you think you actually do. Due to the way that the game calculates available building space, many players’ cities end up looking very similar – usually it’s something akin to a Milton Keynes or New York City because of how heavily grid layouts are pushed.
Public transport is less a solution for allowing the poorer residents of your city to travel and almost entirely just a way to mitigate the amount of cars on the road. Buses, as the most convenient public transport, can be placed literally anywhere you want and people will use them if it’s “faster” (the only metric by which citizens actually decide what to use), regardless of social status. Trains and subways are woefully underdeveloped, something that the DLC has done little to help with – train stations have exactly one, massively space-wasting default building to use for both cargo and passenger lines, while metros have a single 2×2 tile as the only overground presence they have at all (and neither system interacts – no overground metro tracks). The only really “useful” DLC transport is the monorail, but it can only reasonably be built in dense metropolitan areas due to a huge amount of noise pollution, and its lower-capacity counterpart the tram is heavily limited by the road types it can be built on. If you’re really, unbelievably stupid, you can build zeppelins, I guess. Mods can’t carry the entire burden of what the game misses out on – while some have tried to solve underdeveloped systems with things like the Metro Overhaul Mod, they’re still held back by the game’s capabilities, and since the more mods you have installed the worse the game itself performs, you’re somewhat limited as to how much variety you can mod in.
The focus of urban city development on the development of huge avenues and roads is historically a heavily political decision. In Paris in the mid-1800s, the Haussmann renovations would massively displace poor neighborhoods by destroying homes, to be replaced with huge avenues or large green spaces, meanwhile making the city’s aesthetic more uniformly bourgeois. Similarly, the grand infrastructure plans of the Eisenhower Interstate Highway System in America, aggressively lobbied for by major automobile producers, would cut straight through poor, black and minority neighborhoods, selectively demolishing and separating entire areas to displace minorities in order to benefit white citizens.
The abundance of roads around the world is almost entirely due to the political pressure applied by car companies – cars themselves are expensive, difficult to maintain and pretty dangerous, but because they have at this point so completely dominated the means of travel due to (entirely manufactured) convenience it’s difficult for many to cope with the daily grind without one. Meanwhile railway networks, which offer far more convenient, safe and affordable travel, are often hampered by government policies that privatise and divide these services in order to benefit the middle class, meaning cars are depended on even more by the working class. In the UK and Japan the problem of overcrowding on poorly-operated and expensive private railways is a serious issue.
On the other end of the spectrum, efforts to reduce traffic in areas usually just involve redirecting it via paving over roads for pedestrianisation; for example, Buchanan Street in Glasgow or the former Elephant and Castle roundabout in London, recently converted to a two-way operation. Like the large roads demolishing neighborhoods, a lot of these pedestrianisation projects exist mainly to gentrify neighborhoods, pushing up land prices and desirability in order to price out the poor residents – in the case of Elephant and Castle, the nearby area has been under increased pressure to be “regenerated” and, surprising nobody, also has a significant latinx, black and asian population. Fuck Delancey, by the way.
Cities: Skylines, and basically all city builders, only repeat this history of urban planning uncritically. You don’t need to worry about politics or economy beyond your profits, population and a vague “happiness” meter, your only goal being eventually creating a nice-looking metropolis. Despite roleplaying as the forever-mayor of Nowheresville, with full control over transport, infrastructure and zoning, there’s not much mayoring to actually do. If the problems in a particular area, such as garbage accumulation or unemployment, people just quietly pack up and go, leaving their house suddenly unoccupiable so you can demolish it for someone else to use the space instead. Nobody ever actually kicks up a fuss, even when you destroy their home on a Vogon highway quest.
Last year Dante Douglas described C:S as “a gentrifier’s dream”; he asked, “why should I care about the people of the city? They say nothing when I rip out their sidewalks. They passively chart optimal paths to their workplaces around the traffic-clogged main streets. They are aesthetic, not simulation.” I would also add that the core focus of the game’s urban planning emulation is one that has, historically, been used primarily for gentrification – the fact that alternatives are woefully underdeveloped only adds to the problem. You can, of course, play in a manner that does its best to avoid this bias (at a significant disadvantage due to the mechanics), but it’s important to remember what the game’s attitude to urban design naturally defaults to.