Alongside the traffic-choked streets, Manhattan's sidewalks are clogging up, too.
New Yorkers may be used to slow motion on four wheels, but now sidewalks are filled with outdoor cafes, food vendors, people handing out fliers, texting-distracted pedestrians, tourists and, well, people of every sort.
While 1.6 million people live in Manhattan, the borough absorbs a weekday population of 3.94 million, according to a May study by the Rudin Center for Transportation Policy and Management.
Sidewalk obstructions and masses of people -- with varying ideas about sidewalk etiquette -- can turn major avenues into obstacle courses.
At peak times, 9,624 people an hour pass the Conway store in midtown at 450 Seventh Ave., according to recent data collected by The 34th St. Partnership.
"Seventh Avenue is by far the worst" for pedestrian congestion, near the entrance to Penn Station, said Dan Biederman, the partnership's president. An estimated 11,952 people per hour pass through the exit on 34th Street at peak times, according to his organization's June count.
Biederman is particularly peeved by vendors taking up sidewalk space, but also concedes that too-narrow sidewalks and long lines of passengers waiting to board intercity buses further frustrate residents. Add to those obstacles hand-holding and luggage-toting tourists, human billboards and newsstands.
While the number of newsstands has been flat since 2003 (there are 267), sidewalk cafes have jumped from 722 to 1,153, according to the Department of Consumer Affairs.
"Of course it's a problem," said Wally Rubin, district manager of the Community Board 5 in midtown. "We see a street intrusion policy that needs to be evaluated and the need in certain cases for the sidewalks to be widened."
Residents gripe about the obstructive habits of the 50 million tourists who flood the city each year -- sometimes venting directly to the sources of their ire. While walking in midtown recently with eight other students to inspect college graduate programs, "Someone yelled 'Oh -- tourists!' at us," and not by way of friendly greeting, said Kelley Mason, 21, of Baltimore.
That man would likely score poorly on Leon James' "pedestrian aggressiveness syndrome scale" -- a set of 15 characteristics developed by the psychology professor at the University of Hawaii at Manoa that includes muttering or making insulting gestures, bumping into and having thoughts of violence toward other pedestrians.
While tourists tend to look around, those engrossed in texting and cellphone conversations do not.
In a 2006 Department of Transportation study of pedestrians in lower Manhattan, 13.5 percent were either using a cellphone, smoking or eating. While people wearing headphones tended to have faster walking speeds (4.64 feet per second) on average than those with unplugged ears (4.27 fps), cellphone users were slightly slower (4.20 fps).
"I walk in the street to avoid pedestrian traffic," said Michael Popielarz, 20, of the East Village.
While increased density can increase stress, developing empathy for strangers can help you better tolerate the obstacles they can become, said Shamir Khan, a midtown psychologist. Your perspective on how fast people should move and accommodate others is not the only valid perspective, counseled Khan. If you can't imagine that the pedestrian obstructing your path may be texting her boss so as not to lose her job, try imagining her "as your mother or someone else you love," Khan said.
Or you can take solace in the fact that you are in one of the world's most popular places. The teeming sidewalks prove that Manhattan is a successful "activity center," said Mitchell Moss, director of the Rudin Center and co-author of the study that showed almost 4 million people a day in Manhattan. "No one feels good walking on an empty street. Empty streets are a sign of failure," he said.