In where I live, this kind of elevators are mostly found in commercial and industrial buildings built in the 60s, which many are still in use.

The door on the outside is usually locked to prevent people from accidentally falling into the shaft; in order to use the elevator, you have to press the button, wait until the elevator reach your floor and the door unlocks itself, then pull open the door, slide the gate open (newer model has electric sliding gate/door instead) and enter the elevator. Leaving the elevator is pretty much the same process in reverse except that you have to wait for the door to unlock which allows you to push it open.

In theory the elevator won't move until you close the gate and the space is too narrow for an adult to squeeze in without blocking the gate (if the elevator is well designed, that is), however the elevator's obsolete design, slow response (sometimes half of a minute) and jerky movement are more than enough to convince you that the elevator could malfunction and start moving anytime - it doesn't help that the door will be locked automatically when closed and it gets extra scary if the elevator was one of those newer models which the gate would close itself after some time (for some unknown reason, this kind of elevators always have a very short "waiting time" compared to modern ones we use nowadays).

I took those elevators a few times before to visit shops opened in older buildings and they are frightening enough to make me not wanting to visit those shops again unless it was absolutely necessary. Fuck those elevators.