Wait Time for Elevators
People hate to wait. If there are long wait times for passengers, there's probably a problem with the elevators related to equipment condition or legacy controls, such as the use of relays. You need to measure wait times during peak and off-peak times and adjust equipment use as needed. Theresa Christy, a mathematician at Otis Elevator says that people get impatient and agitated after 20 seconds of waiting. Studies show that people overestimate
Figure 8.2 Esclator.
how long they've waited in a line by 36%. Remarkably, some building owners that have had complaints of elevator long wait times have determined that the complaints are the result of boredom, and have responded by making the lobbies more interesting.
Elevator speed is important. One needs to periodically monitor the time it takes to go from the bottom to the top floor. This is a good metric to measure and observe to see whether the speed is deteriorating, indicating issues with the equipment.
The speed of an elevator is related to the different type of elevators (hydraulic, geared-traction, gearless-traction) and how tall the building is. A three-story building using a hydraulic system elevator has a speed around 100 feet per minute; a geared-traction elevator in a 25 story building may be 700 feet per minute; real high rise buildings have speeds over 1,000 feet per minute. During the recent renovation of the Empire State Building, the speed of the elevators was increased to 20 feet per second to get more people up to the observation deck. Passengers now rise 80 floors in about 48 seconds (without seatbelts).