I never cease to be impressed as to how deeply flame-etched into people’s consciousness is the postapocalyptic-urban-dystopian picture of NYC established in the early/mid 80s, and it’s already 2016.
Like he said, of course you need to be aware of your surroundings whether in NY, Los Angeles, London or Paris. In NY in this day and age of “see something, say something” you will find if anything more hyperawareness of surroundings on the part of everyone in the street and that helps too.
Now, sure, you still can’t predict the random lunatic, and in any conurbation of that size you will have more of them, but at the same time the very large number of potential targets said rando loon has to choose from also shifts the averages in your favor.