The setting of my installation will be from the front of the first level's elevator to the stairway.
An infra red sensor is used to detect movement when one walk towards the elevator. When movement is being detected, it will send a signal to the arduino microcontrollor and there'll be sound and lights flashing down at the stairway to attract the person's attention. The idea of this project plays on human instinct of curiosity. When lights begin to flash and sound begins to play, out of curiosity, one might walk over to the stairway to check out what's on. Once they arrive at the stairway, they might just walk up to the above levels without walking back out to wait for the elevator.