Here is the nether hub and nether highway from the Aqua Ruby server. We have been working on this for a little over a year off and on.
The design of the highway changes depending on what biome it goes through. Right now we have designs for the Nether Waste, Soul Sand Valley, and Bastion Ruins.
The highway connects all major bases around our server, some players customize the highway that is directly beside their portal.

This project is a forever-in progress type thing, as more bases are created, the farther we extend the hub.

I thought you all would like the designs :)