Gotham Knights looks similar to Arkham Knight in that players will be able to travel through Gotham City. The city itself is pretty big, which means players will likely have long distances to travel. Gotham Knights introduces a system for getting around in the form of a Fast Bat, which is basically the game's version of fast travel.
Can I fast travel in Gotham Knights?
Yes, Gotham Knights will have fast travel in the form of Fast Bat. As seen in the gameplay trailer (Shown at 6:50), players will unlock fast travel points and then use the Fast Bat to get to those locations faster. The demo showed the player needed to go 400 m to get to the mission location even with the Fast Bat, so there might not be many fast travel points to use.
From what it sounds like, maybe players will need to clear the rooftop of enemies or something like that to unlock fast travel points. There's nothing unique to the rooftop shown in the gameplay trailer, except for a tarp with "X8" on it. Either way, players can use these points so that they don't need to take a while to travel across the city.
For more on Gotham Knights, check out Gotham Knights — Pre-Order Bonus, Special Editions or Gotham Knights no longer releasing on PS4 and Xbox One here on Pro Game Guides!