New Yorkers' complaints that tourists walk slowly and block sidewalk traffic is so proverbial that Improv Everywhere painted a traffic lane for them. So keep moving.
But that's only one point of etiquette that newcomers should learn. Nathan Pyle has 11 other instructions presented as animated .gif files. You can view them all at the link.
Link -via Nag on the Lake
P.S. Why is the train car empty?