That is a very British sign.
However, as a typography perfectionist, it really bothers me. The font is "Johnston" which is, basically, the London Underground font. But the
kerning here is all wrong. The tailed lower-case l does not fit neatly in the words; there is too much gap (mind) between where the l stops and the next letter starts. Other letters have similar problems; in the word "Warning", there is too much space between the W and the a.
Also the vertical spacing between the "Level 5" headline and the text underneath it is too small. The "g" in Warning and the "f" in platform almost touch.
This sign was not created by a signage professional, and I question its legitimacy.