Removes (technically extends) the world border so that u no longer get teleported back when u try to drive outside of it.
If u go outside of the map (the actual world border) your game WILL softlock, if ur in that position and u try to reset with back on track the game will just crash aswell.
However I have noticed that it seems like this does not happen at all if u are playing offline.
If u use back on track u will get teleported back to the closest road so dont do that either unless u wanna go back.