There are a couple of different types of elevators in the Valley: large transport elevators for goods and passengers that travel between several different provinces, and smaller cargo elevators that only connect two provinces.

Cargo elevators generally stay at the topmost position when not in use, and while they can be operated by anyone, there's typically a guard posted at the top to keep bandits and contraband from gaining access to the upper provinces. Obviously this system works perfectly 100% of the time, and no one has ever successfully smuggled anything via cargo elevator.

You can read even more about elevators in this appendix post.