> the attackers had started fires in "conduits carrying multiple (fibre-optic) cables" that relay "safety information for drivers" or control the motors for points that change rails... Farandou of SNCF said: "There's a huge number of bundled cables. We have to repair them one by one, it's a manual operation" requiring "hundreds of workers".

Just wondering: is there a reason why there needs to be a bundle of fiber optic cables to carry safety information and control the rails? Is that not overkill? I assume wireless/cellular networking is not robust enough, but what just standard-ass copper wires, like the telephone lines? I assume the reason is that they're transmitting more than just what was named in the article, but all I know is what I read.