The sidewalk belongs to babies. Babies and dogs and tourists. The sidewalk does not belong to strings of friends or to clustered nuggets of slow-moving family. Walking side-by-side-by-side so the poor schlep in the on-coming pedestrian lane has to step down off the curb and be splattered by freezing rain is not authorized by New York City's Department of transportation. Neither is slowly meandering in a loose daisy chain of matching DNA so the poor schlep who's late for work has to wait for a brief gap in the amorphous and idle family formation to dart ahead. These people actually do not exist as legal entities and should be treated as such.
Nannies with double-wide HumVee style strollers are NYC's sidewalks' priority. The careering mother who was implanted with extra eggs and so birthed her own portion of the city's boom in twins or triplets retains the right to 5/12 of every foot of sidewalk in New York (as negotiated with Bloomburg-- they also own Harlem now, apparently).
The city's infants are followed closely by its dogs (soon to overtake human babies as the primary recipient of adult affection). Whether they are walked in gigantic barking sniffing canine clouds by the neighborhood dog walker or by the half asleep owner who reluctantly threw on a pair of nitty sweatpants and an open mouth to allow He-Bear the microscopic full breed to stretch a leash across the street and cloths-line the unaware, dogs and their keepers own the next 4/12 of that foot of sidewalk.
Tourists move for the most part in efficient packs that feel the need to stop from time to time to take pictures of artifacts stolen from their homelands. True they slow foot traffic and frequently wear matching wind breakers and drive the price of real estate up by buying whatever ridiculous scam developers can cook up in the form of luxury city living and will most likely erode all of the city's infrastructure (if the chain stores don't do it first) but they are unaware by definition and must be forgiven for taking those last three inches of sidewalk.
Everyone else in New York walks on the edge of their feet. They flood into the gaps the tourists leave when they move on to their next sight. They tip-toe along the utter lip of the curb. Some blast down the center of the sidewalk, unaware that they have tipped over two strollers and upset the world's greatest picture of a Central Park squirrel looking as if he's about to hail a taxi. When caught these people are shucked of their citizenship and forced to stand on the corner and hand out flyers for strip clubs, weight loss programs, discount suits and Jews for Jesus.