How Train Signals Work

Using trains to move around resources in Factorio will make factory life much easier. Learning how to manage your trains so they don't crash into each other is crucial to ensuring your pipeline doesn't come crashing to a halt.

Building Train Signals in Factorio is the easiest way to avoid any potential harm to your trains as they shuttle different materials around the factory. Looking for information on how they work? You've come to the right place!

• How Train Signals Work
• Bi-Directional Travel
• Building Intersections

How Train Signals Work

Train Signals work by dividing railroad tracks into sections. This allows the game to understand when the track is being occupied by a Train.

For instance, in the screenshot below, you'll see that we've placed a Train Signal in the middle of the track. This has now divided the track in half. The left side is a magenta color, which indicates that it is now a separate block from the right side of the track, indicated by the light blue color.

The Track Signal above has a green light, which tells the train it can freely progress along the track without being in danger. If the light was red, this would indicate that it is not safe for the train to progress as the magenta block is occupied by another train. This comes into play when you start building intersections with multiple trains.

Bi-Directional Travel

The position of your Train Signal also tells the train which direction to travel. Train Signals placed above the rails will allow the train to move in one direction while placing a track below the rails will allow it to move in the opposite direction.

If you want a train to move back and forth on the same rail, you will need two train signals placed above and below one another.

Notice the yellow arrows on the magenta side of the track. This shows that placing the Train Signal below the tracks will allow the train to also go left once it reaches the new block created by the Train Signal.

Building Intersections

Building intersections in Factorio gets a little more complicated, however, the basics of Train Signals still apply.

When building your intersection, you're going to need to ensure that the actual crossroads is a separate block from each direction. This is done by placing Train Signals at the corner of each direction as seen in the image below. This will make the intersection its own magenta block and tell the trains not to cross if it is being occupied by another train.

As one train enters the magenta block, all the Train Signals will go red, stopping any other train from entering until the current train has made it past.

If you want trains to be able to go back and forth on the same track, remember to place signals on both sides of each track to allow for bi-directional travel.

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