[rayiner]

It should be noted that Manhattan is a lot denser than it is on paper. It's daytime population is more than double its residential population. Midtown Manhattan on a weekday probably has several hundred thousand people per square mile, rather than the 70,000 per square mile nominal density of the island.

[maratd]

Bingo. There are a ton of people who live in the other boroughs, New Jersey, etc. that commute into Manhattan for work every work day and even on the weekends for fun.