The world of Spider-Man on PS4 will supposedly be pretty big. How big? Take a look at this tweet: 

Sunset Overdrive had a massive map for a game released in 2014, but in the wake of games like Zelda: Breath Of The Wild and the aforementioned Witcher 3, the tweet says a lot without really saying anything. 

One thing that is worth mentioning though is that the Vertical map for Sunset Overdrive added perhaps more of a challenge than those other games and with NYC featuring skyscrapers and junk like that the vertical nature of the city will undoubtedly come into play. Several times larger is still pretty large so people should have to web swing for at least several minutes before reaching one end of the map coming from the other. Spider-Man is set to release in 2018. 

Source: IGN