Only use the station as main streets / plaza’s where you build hotels and shopping facilities As soon as you build a road from a monorail station and add any building, it’ll count as a connected road, even when there is no road between the monorail station.
This is how you get 5 star facility rating.
And if you are like me, or just get tired of trying to remain stuck at 4 or 4.5 facility star rating on an island, this is how you guarantee yourself the 5 star rating.
For me, the 5 islands are just places I need to go through to unlock the dinosaurs and skins to have more variety on my sandbox island.