Factorio Forums

TL;DR

Belts where both sides are moving in opposite directions

What ?

Belts where both sides are moving in opposide directions. Could loop at the end automaticly, or aditional 'looper' could be required. Special splitters should be considered too.

Why ?

So it would be easy to create looped belts when there is not enough space for two normal belts.

That's technically 2 1-lane belts going opposite way.
I'm almost certain this will never happen.

Looped belts (with so small amount of items on them) make only sense for some quite experimental stuff. There can be found lots of in the forum.
If you really want to have a good time with Factorio I recommend using some kind of boxing mod, which increases amount of items on belts to reasonable numbers. But then also: a single lane is just no good gameplay.