The Highway is an area that is accessible from interacting with the taxi in Onyx Tile World.
Features
The area you are transported to from the taxi is a small intersection with blocked-off buildings at the edge of the area (which suggests that there may be more areas accessible from there). Most creatures will react to the glasses effect. In this version, the Fairy effect can be obtained here by going into the small hut in the main screen with a Robot Guard standing next to it, however this seems to be a temporary location.
When you travel horizonatally in any direction from the intersection, you will end up on a long, yellow road with a starry sky in the background. If you travel to the right, you will come across a tunnel with a portal to the Purple Neon Maze (by chainsawing the red face on the wall), although the maze itself is blocked in the most recent version.
If you continue to travel right from the tunnel, the "evil" ghost of Urotsuki on her motorbike will be cruising in the upper lane. If you touch her, you will be sent to the westernmost area of this world, with an intersection that is the entrance to the Gray Road (you will end up here if you keep going left from the area where you got out of the taxi).
Going all the way right from the tunnel will take you to a blocked off area (which seems to be where the Fairy effect will be located in the future).
Connections
Purple Neon Maze (closed for renovation)