Switchboard

Switchboards are green movable platforms in Super Mario 3D Land and Super Mario 3D World. They are divided into two pads that display arrows pointing in opposite directions. Across the middle of the Switchboard is an axle with wheels, enabling it to move on rails. If the player steps on one of its pads, the arrow on the side they stand on turns yellow and the Switchboard moves on rails in the indicated direction.

Super Mario 3D Land
Switchboards first appear in Super Mario 3D Land in World 1-3 and appear in large numbers in World 1-4, Special 3-1 and Special 5-3. The rails under a Switchboard may have blunt ends, making the Switchboard come to a stop once it bumps into them. However, some rails do not have ends and the Switchboard will simply fall off the rails if led there. The Switchboard will safely land on other rails most of the time, but in some situations it may fall into an abyss, bringing the character along with it and causing him to lose a life. The Switchboard accelerates on inclined rails, making it more difficult to control.

Super Mario 3D World
Switchboards return in Super Mario 3D World, appearing in Switchboard Falls and Cosmic Cannon Cluster where they form the main mode of transportation. This time, the border around the platforms is white instead of green. In this game, the player has the ability to tap and hold onto one of the pads on a Switchboard to make it move in the desired direction, without involving the playable characters.

Super Smash Bros. for Nintendo 3DS
Switchboards also appear in Super Smash Bros. for Nintendo 3DS in the final portion of the 3D Land stage, albeit without the arrows. They can be destroyed by Spike Pillars, which serve as stage hazards in the stage.

Mario Party 10
The Switchboard also appears in Mario Party 10 in the minigame Bullet Bill Bullies. The solo player has to move sideways with it to dodge incoming Bullet Bills from other players.

Trivia

 * A similarly functioning type of platform with four arrows and directions that it can move in appears in Hazy Maze Cave in Super Mario 64 and Super Mario 64 DS.
 * Another similar platform appears in New Super Mario Bros., more specifically, in World 7-2 from that game. It is also in the code of New Super Mario Bros. Wii.