There was an interesting discussion recently on London By London about notices announcing 'good service' on the underground. The person who started the discussion contacted London Underground and suggested that it was for us the travellers to decide whether or not the service was 'good'. Surely all they were entitled to say was something like that the service was 'normal'. The LU spokesperson said they had decided 'good service' would be easier for tourists to understand (which made me wonder why they keep talking about 'alighting' rather than getting off the train). This notice seems to me to suggest even more strongly that the service has been critically assessed and judged to be good.