I was thinking a map like in the 2D Fallout games for fast-travel and not in-world traversing. The map starts dark with only your immediate surroundings/vault/settlement marked out and from there you start to uncover it. Settlements and large things are added by passing near them, which is reasonable because they would be easy to spot from a distance, other things requires more exact coordinates where you travel to specific spot and then go in to the world to find the actual location. If it's close enough the player would then stand outside the entrance to a vault, cave, small camp or mysterious hole in the ground. If they go from the map into the world at a random spot it would just be wasteland, unless they are incredibly lucky or know beforehand where something is located.
I'm not NoMutantsAllowed levels of insane but I have some absurd adoration of the old games. I played so much Fallout 1, during summer break my routine was to wake up, grab a cup of tea, play Fallout with breaks for lunch and dinner... Then go to sleep, repeat.