Factorio Forums

Is there a mod out there that let's me connect a red or green line to rail tracks so I can send a signal down the line just so I can build a checker to make sure my automated bots fully build the line and not bits and pieces of it when they also have to deal with landfill?

You could use the train pathfinder to check whether there is a continuous rail. Add a dummy branch on one side with a locomotive behind a force-closed signal. On the other end, add a station with a unique name, and add the station to the locomotive's schedule. Enable "read train count" on the station. When there is a continuous path, the station will read C=1.