It’s not hard to see what the problem is here. Presumably on this day, the private management of Southern Cross Station were blissfully unaware that in the evening peak hour, more people want to go into the station than come out of it. Thus only one of the three escalators was running in the right direction.
Similar problems are seen at Melbourne Central, with management often not twigging that escalators from ground level down towards the station need to match the flow of people.
(Signage reflecting the common practice of “Stand to the left” wouldn’t hurt either, for the benefit of those rushing to catch a train — though at least in this case the more athletic can take the stairs.)
More about PT Problem Of The Day, including how you can contribute your photos.