This image was acquired from
flickr. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
Currently the passenger is notified of the existence of platform in the bottom level when coming down the escalators from the top level.
sign with arrow needs to installed on the pillar facing escalators alighting the escalator in order to direct passengers whether platform e.g. is on the left of right of the escalator the moment