Simple rules

Does the keeping left while on escalators at MRT stations apply to all stations? Or is it just the select few at strategic locations like Orchard, City Hall, Raffles Place etc.?

I think it applies to all MRT stations right? Correct me if I am wrong. Then when can't some commuters understand this simple rule and keep left instead of jamming up the way and preventing people who are in a rush to move off first?

This is such a simple rule and it doesn't take much to display some consideration right?

I don't understand people sometimes.