The particulars of comic books are often inconsequential to the point of being silly. If you try to logic out how everything works, mostly you just find out that it doesn’t. Somewhere along the way you have to suspend disbelief, even for Batman. For Superman, one of those things is the location of his two primary residences, neither of which makes any sense.
Let’s look at the particulars. Metropolis is the flip side of urbanization from Gotham, the bright city of the future where everything is happy and sunny. The city is heavily influenced, historically, by Toronto and New York City. It’s canonically a coastal city with a massive port, which we even saw in the latest take on Metropolis in My Adventures With Superman. DC Comics often puts the city where New York City is. Multiple DC products, though, have placed the city in Delaware. The city is also often characterized as being across the river from Metropolis, to enhance that “other side of the tracks” feel that the two cities have. That, too, would place Metropolis in Delaware more than in New York City.
Smallville is a rural farm town. In many depictions of Superman, such as Superman: The Animated Series, Smallville is specifically located in Kansas according to various characters’ statements. The Smallville series also places it there. Superman & Lois and the Arrowverse place it in Kansas as well–specifically in Rice County. Zack Snyder’s DC movies used locations in Illinois, and at least one version of the comics placed it closer to rural Pennsylvania. The 1978 Superman film also places Smallville in Kansas, even though the backdrops look distinctly un-Kansas-like, with mountains and fields being visible in the same shots. Thank Alberta, Canada, for that.
It makes sense, right? Clark is from the heartland of America, a good country boy who grew up with baseball and football and fields of golden wheat. But Metropolis is the big city of big cities, the coastal urban center that is the height of new technology and fashion. They should be distant from each other to signify what a big transition Clark is making early in his life.
However, if you pay attention to how these stories use the two cities, things get much weirder. When it’s just Superman going between the two, it doesn’t matter. Dude can fly across the United States in minutes if not seconds. A trip to Smallville is less time for him than a trip from your front door to the mailbox.
Smallville tries to make it work by making Metropolis a city in Kansas, close enough to Smallville that you can see the skyline from certain vantage points. The Smallville Season 11 comic even gave the city a Kansas zip code.
But in Superman & Lois, the Kent boys are frequently seen driving to Metropolis. In My Adventures with Superman, Clark drives to Smallville with Lois and Jimmy, and it’s implied that they did it on a single day. In those cases, either Smallville isn’t in Kansas or Metropolis isn’t a coastal city. Both are verified as being true, even though they literally cannot be.
The truth is that Smallville and Metropolis are as distant from, or close to, each other as the plot requires. The other truth is that none of this matters. When you try to spell out where these places are located, we see how many sources of information there are. There are countless continuities in the comics, pre- and post- various Crises. There are movies and television shows that need to fit the two close enough together to make sense in the runtime of a given storyline. There are sourcebooks like 1990’s The Atlas of the DC Universe, created for the DC Heroes roleplaying game. With so many authors, none of these can truly be called more canonical than any other.
That means that depending on where you’re standing and what needs to get done in the story, the distance between Metropolis and Smallville is constantly changing and unobservable, stuck in a quantum state that allows anyone necessary to get there when the story needs to. It doesn’t make sense, and that’s okay, because Superman still rules.