If you have a path or road that is traversed by rail, then you may want to use an automated gate that closes, protecting you from crashing into the a train.

This tutorial shows you how to make these automated gates using the circuit network.

There are also options for warning lamps, with flashing using combinators.

Here's the video tutorial. Text and screenshots continue below.

To do this you need:

• A gate with adjacent wall piece
  
• A rail signal block covering the area you want protected
  
• Green or red wire
  
  • Optional (alert lights)
    
  • Lamps
    
  • Electric poles or substations
    
    • Optional (flashing alert lights)
      
    • Combinators

1. Lay down a gate covering the area you want to protect.
2. Place a piece of wall at the end of the gate to create a gate controller.
3. Make sure that the area you want protected is covered by a signal block, which requires a signal at the start, and end of the area.
4. Connect the gate controller(s) to the rail signal where the train enters with green or red wire (green shows up less).
5. Select the mode of operation on the gate controllers to “open gate”, and the open condition to RED (under the signals tab) = 0.
6. Change the output signal yellow to red, so that when the signal is on yellow, a red signal is sent to the circuit network. This means that the gate will close before the train enters the protected area.

1. Place lamps down near the gate controllers and signal, make sure they are covered by electric poles or substations.
2. Connect the lamps to the gate controllers with green or red wire.
3. Change the enabled condition to Anything (under the signals tab) > 0. This will show both red and green. If you want only red or green to show, change the enabled condition to the respective colour.
4. Change the mode of operation on the lamps to “Use colors”.

1. Paste the provided blueprint to an area near the gate controllers and signal and connect the circuit to the second last combinator.
2. Timings and flash length can be adjusted by changing the numbers on the first and third combinators.

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

Please note that the circuit network can be spread out by connecting the red or green wires over electric poles or substation. You can then, for example, place warning lights further away.
This is my first guide so please give criticism and feedback.