It might be useful sometimes, to send circuit signals over long distances. I personally never used it for anything, but when we were playtesting a while ago, Boskid insisted that we include circuit wires into our rail blueprints, because you never know when it might be useful.
I felt uneasy about it, because it goes against the coding principle of "write it when you need it", as it adds a bloat for something which might not even be useful later. But I understand, that if it actually becomes needed, it would be way harder to fix later.
To avoid this dilemma, we added a long requested feature of wireless circuit transmission using Radars.
There are a lot of ways to do it, but we wanted to keep it simple. So we decided that there is just a single radar channel for each surface (still separated between red and green). This means, you don't have to configure anything, you just connect the wire and you are ready to go. If the radar loses power the circuit connection is severed.
