From Starbounder - Starbound Wiki
Directs rail riders to different paths
Rail Switch is a rail object. When placed on a rusty or composite rail, it can direct riders to other connected tracks.
The Rail Switch functions by acting as a rail piece which can be turned on and off. When the Rail Switch is off, it acts like an empty space, and nearby rails will not connect to it; in this state, the center looks like a ball. When the Rail Switch is on, it acts like a rail, and nearby rails will connect to it; in this state, the center looks like a plus sign (+) laid on top of a circle.
If the Rail Switch is not connected to any inputs, it will default to the "on" state.
- Cheerful Giraffe: Added