Factorio Forums

So after ~120h play time I accidentally tried out to put two different underground belts "on top" of each other and it worked perfectly: Is this known / wanted behavior and did anyone use it for some nicely compressed setups? If so, I would like to see them.
I mean mean, e.g. for making blue circuits, you could let a yellow underground belt with advanced chips run on the same line as a red underground belt with green circuits ...

It is known behaviour. Typically referred to as belt braiding.

Cool, thx. Now I have a keyword to google

The Transport Belt Madness scenario teaches you this, but I had no idea until I got around to playing that.