street wise

this is a pic of a sign that we saw in london and liked. what it really means for those london commuters, i haven't the slightest idea. anybody able to help me out on that one?! i'm not sure why a street sign would advertise a change in priorities, but i like the idea that we can change ours, if those be those things that are most important to us and direct our lives. i'd like to think that i try to model my life after that of Christ, but i know i don't always pick the best or healthiest things to live for. i'm glad that can change. i still want to know why that would be on a street sign though.