This is a convenient mode of transportation to reach the lower maze levels (with the exception of Level 10) in Wizardry: Proving Grounds of the Mad Overlord. The express lift is located behind the door that says "Private Express Elevator" in Level 4 (10E/2N). The door can only be passed by the party if they possess the Blue Ribbon - a token given by Trebor for defeating the monsters in the Monster Allocation Center on the same level (12E/15N).
If the characters try to enter the elevator without the Blue Ribbon, they will become sick and weak, lose consciousness and awake in front of the door again. This is, however, scripted. The characters do not lose hit points and their status is not affected. They just cannot pass the door without Trebor's token.