Scattered throught the map are transit locations, these are points that once visited will allow you to 'fast travel' to your destination by instantly teleporting you there. To use a transit location you must view the whole island map and tap on them as though you were setting a waypoint there.
The transit locations themselves are usually a hut with a fence around it. The hut will contain a bed and a chest with a small amount of random loot in it. You will also find a device near the hut in the shape of the island which you to instantly travel between transit locations. How it works though is a mystery.