Route your belts freely underground.
Mods introducing new content into the game.
Augmented or new ways of transporting materials - belts, inserters, pipes!
When using mods that change speed of belts like https://mods.factorio.com/mod/DoubleSpeedBelts, the speed of the connectors are wrong.
I suspect this is a problem with Double Speed Belts not looking for linked-belt prototypes.
(probably fixed)
