There's always belt weaving. (For those that don't know, belts of the 3 different tiers don't "share the same underground space", and so can be overlapped on "t

There's always belt weaving. (For those that don't know, belts of the 3 different tiers don't "share the same underground space", and so can be overlapped on "top" of each other through the use of underground belts.)