How busy are the streets in New York City on New Year's Eve? I've seen TV shows like How I Met Your Mother show it as one unyielding crush of humanity, but I was wondering whether that is actually realistic. Is it possible to travel far by foot or other means, or are you limited to the immediate surrounds of your residence?
I haven't done a Times Square New Year's Eve in over a decade, but I'd say if you can manage changing trains at 42nd Street during rush hour, it's no great challenge.
Compared to most American cities (if not, say, Mumbai), New York City is an "unyielding crush of humanity" on any ordinary day. The sidewalks are crowded, the subways are crowded, the stores are crowded. The good news is that on account of this, New Yorkers are quite accustomed to negotiating crowds wherever they go. You find others in the crowd going the same direction as you are and go with that flow rather than trying to move against it on your own… or you learn to push and be pushed a little. That's how the stereotypical New Yorker is, to this day, always rushing around town from appointment to appointment— not working endlessly at the office like a Tokyoite or on the mobile phone stuck in traffic like an Angeleno.
New Year's Eve is the biggest party day, but there are other big parties like St. Patrick's Day, not to mention dozens of parade days, street festival days, game days, and other excuses to congregate in public areas. Inside Times Square or wherever the main event is, people will be shoulder to shoulder, but in the area beyond only an extreme agoraphobe would be unable to move about. Road travel is tougher, as surrounding streets may be closed during special events and it may be hard to find a taxi, but that's true of any city.
If you find a group of immobile tourists on New Year's Eve in Manhattan, it's probably the cold. People seem to underestimate how cold it gets, since the tall buildings both block out the sun and channel stiff winds.
If anything, I'd say that a show like HIMYM understates just how bad the heart of the midtown Times Square festivities are, post 9-11. Because people are so heavily penned in and the lanes of traffic are so controlled by security, there is little to no mobility for actual revelers.
As for the rest of the city, it's busy, but not any worse than any other busy holiday evening or rush hour - the crowds are just a bit shifted from their usual locations, away from office towers, and closer to bars and the waterfront.