A recent episode of The Flash accidentally called attention to the inconsistent geography of the Arrowverse and the biggest problem with DC Comics' fictional cities in general. One of the major differences between DC Comics and Marvel Comics was that the former established most of its superheroes in non-existent cities like Metropolis, whereas Marvel was typically set in real-world locations like New York City. This led to a lot of confusion regarding where certain cities were located and that confusion has extended into the Arrowverse, where the tradition continues with Supergirl protecting National City; a Californian metropolis modeled on Los Angeles.
The problems with the Arrowverse began with the pilot episode of The Flash, which established that Barry Allen's hometown of Central City and Green Arrow's Starling City were roughly 600 miles (965 km) apart. This didn't match up with later episodes of Arrow, which established Star City as being fairly close to the real-world city of Seattle, or later episodes of The Flash which placed Central City in Missouri, fairly close to the real-world location of Kansas City. The distance between Seattle and Kansas City in reality is over 1800 miles or 2900 km. The Arrowverse has a similar problem regarding the location of Gotham City, which has been shown on different maps in Batwoman and The Flash to be located either somewhere between Chicago and Milwaukee on the west side of Lake Michigan or on the New Jersey side of Delaware Bay.
The Flash season 7 episode "Rayo de Luz" highlighted these issues, as reporter and light-empowered metahuman Allegra Garcia tried to track her cousin, the metahuman assassin Ultraviolet. At one point Allegra showed STAR Labs scientist Chester P. Runk a map she had made of Ultraviolet's latest crimes, with the most recent ones occurring in Metropolis, Opal City, and Central City. The highlighting of the states on the map showed Metropolis to be in southeast New York, Opal City in east Illinois, and Central City in western Missouri. While the location of Central City is consistent with previous episodes of The Flash and Opal City's location in the Arrowverse has never been confirmed, the idea of Metropolis being in New York is new, despite the famous City of Tomorrow (as it is often called in the comics) being modeled on New York City by some artists and writers.
In the comics, Metropolis is usually said to be in Delaware, set opposite Gotham City on the other side of Delaware Bay. However, in Superman and Lois, Metropolis was implied, in the episode "Broken Trust," to be close enough to Smallville that their high school football teams played against each other as part of a regular season game. This would be impossible in reality, as the Superman and Lois pilot confirmed that Smallville was in the state of Kansas; the center of which is roughly 1450 miles (2334 km) from New York City. Delaware is slightly closer at 1,372 miles (2208 km) but that's still much further than any public high school football team would travel for a game.
In the end, drama trumps geography in the landscape of the Arrowverse. While it might not be realistic for the Smallville and Metropolis football teams to meet on the gridiron, it makes for an interesting story if Jordan Kent can confront the bullies from his old high school after he begins playing for Smallville's team. It also makes it easier to fudge the distances a little for the sake of those characters who can't run across the country in seconds like The Flash.