If you could place a railroad around the world where would you place it? Lets not consider the fact that if you put in the sky or underground it would be a little extra work.
I have heard that a worldwide railroad on the ground creates a lot of lag not sure if this is true, but I have been on a server before with a worldwide railroad and also a sky rail road and there wasn’t a ton of lag. The railroad in the sky I find hard to access and almost easier just to walk on the ground. The underground railroad i feel the same about, but it is even harder with the under ground railroad to access it since there might not be a tunnel down to it within where you want to go.
Edit: I included this in multiplayer since I am considering where to build a railroad in my server and the lagg isn’t a factor if you are in single player