Aerial view of the Rainbow Road using Zan's Minimap mod (left) and the original track from the game for comparison (right).
Rainbow Road is a minecart track built by Spintown with help from NinjaMarion near the Cobble Bitch made to resemble the Rainbow Road track from Super Mario Kart and Mario Kart 7.
It was featured in Episode 211 - Rainbow Road and it is composed of 2 tracks where players race around to see who comes in first. To add to the challenge, players must react quickly once the hoster has said "Go". It also has a height chart posted on a sign in order to see if you are tall enough to ride.
Zack jokingly claims that Spin had duped the wool in order to have enough to make the track. Spin then clarifies that he in fact did not have enough wool himself; rather, he took out a loan from Ninja to finish building the other half of the track.
Minecraft
Rainbow road showed by spintown