Tunnels
They could be built by using a new-added drill, that works similarly to a stacker tower, but reverse, so dumps out the mined material to the end of the "rail" to a storage. Or just by mining but building a ceiling before, like the mining walls. Then we wouldn’t have to mine the whole Mount Everest to get one path :P. Tunnels could be built by setting a tunnel route, like bridges, and building a drill vehicle in a special depo, or by placing a drill build and settings its route, like in a stacker tower.