Oh, definitely, I agree. You need at least 2 (probably 3 or 4 for extra redundancy) shafts. But you need them to be usually one-way shafts. So everyone going up

Oh, definitely, I agree. You need at least 2 (probably 3 or 4 for extra redundancy) shafts. But you need them to be usually one-way shafts. So everyone going up gets in at the same door, and the empty cars can fly down the other side to be ready to take more people up.