I'm not sure how inherently unsafe they are compared with regular elevators that have shaft doors but not cabin doors. They can theoretically squish you betwee

I'm not sure how inherently unsafe they are compared with regular elevators that have shaft doors but not cabin doors. They can theoretically squish you between the floor of a rising cabin and the ceiling, and between the ceiling of a cabin going down and the floor. To prevent this, you could place a movable board coupled to a sensor at ceiling of the cabin and the ceilings of the entry "doors". If the cabin starts squishing someone while going down, the board gets pushed upwards, and triggers an e-stop. If it starts squishing someone going upwards, again, the outer board at that floor gets pushed, and again, triggers the e-stop. (The board would have to be able to move more than the elevator needs to stop, obviously). At that point, the remaining risk seems to be similar to regular elevators that don't have inner doors. (Existing installations seem to have solved this passively with breakaway panels and gaps, which is probably good enough, but would make it possible to jump from the cabin into the shaft while it is between floors.)