The hyperloop was created by the player King Neme as a fast way to travel across the map. The map used to be much smaller when the main Hyperloop was created, and until the 4300x4300 expansion, this was enough for travelling around the whole map. After the expansion, The Player Made Hyperloop was created to reach the new, larger areas.
The main hyperloop is marked on the dynmap by pink lines. To use it, all you will need is a boat. Afterwards, click the button and you will be immediately transferred in to the hyperloop.
You used to be able to buy boats for one emerald at the main station in the past, however today this is not the case as getting a boat is free trough the use of /boat. Ender chests are present at all stations.
You can also walk/run trough the hyperloop but it is much slower.
At the outer exits of the hyperloop you can walk out by stepping on the pressure plates at the end of the line. When you're going to the center of the map you will need to hop onto one of the pressure plates in the corners of the room to be transported outside.