U&I / Elevator Location Indicator

Although the elevators today let you know where you have been, U&I provides more informations you can notice with no operations. Imagine that you're waiting for the elevators to go down from the 20th floor to ground floor and a monitor attaching next to the elevator's door marks the lights, green and red,
to let you know where the elevators currently are; green refers to where the elevators are and red refers to which floors the elevators will stop. That doesn't happen in reverse when you are in the elevators so passengers are not confused.