Factorio Forums

So this happaned, they stopped in middle of highly used track part.

Maybe its possible to use wires and make 2 go red when 1 goes red? And vice versa

You need to replace some of the signals in the crossing.

Place chain signals before and inside the crossing, and a normal signal after the crossing.

Slimey wrote:You need to replace some of the signals in the crossing.

Place chain signals before and inside the crossing, and a normal signal after the crossing.

Yep, that's the tl;dr, the problem you (original poster) have is that your trains can enter the junctions without being assured that they will be able to make it out the other side, that's what chain signals are for, they make the train 'look ahead' to the next signal (and that's another chain signal, they look even further ahead, etc.) As long as path through to the next regular signal is clear, the train is permitted to pass the original chain signal in question, and in doing so, reserves the entire path through (prevent another train for entering said path after the first train passed the original chain signal).

For the situation at hand, both signals you circle should be chain, also, avoid non-chain signals inside a junction, as this can let a train enter, but not actually be able to leave if the exit 'normal' signal isn't green.

Same thing with 2 way track that more than 1 train uses:

make all signals on the 2-way part and all signals into the 2-way part chain signals

that way a train can only enter the -way part if it can be sure it will be able to exit it