People like rules in Hong Kong but, on the MTR - where we're inundated with them - it seems they're generally ignored and rarely enforced. It might be useful if the announcements over the loudspeakers, in Chinese and English, actually made sense (although it's possible that might just complicate things further).
A personal favourite is: "When travelling on escalators, hold the handrail, stand firm and don't walk." This is simply juvenile. Has anyone ever stood more firmly for being told to do so? And in any case, why shouldn't we walk on escalators? Perhaps someone fell over once and grazed their arm - but surely that could just as easily happen on stairs?

"Be aware of the difference in levels between the platform and the train," seems to be an awkward way of saying "mind the gap". Or is there something more three-dimensional going on? You wonder how many specialists had to be consulted to fine-tune the message's wording for maximum safety impact. All they've succeeded in doing is mystifying people in three languages.
Finally, though, a new one for the MTR's consideration: "Playing mobile games while walking through stations is maddening to others and is forbidden."