Three New York City issues that often lead to fierce disputes: • Dog Runs • Sidewalk Cafés • Car-Free Parks

Dog versus human.

Baby stroller versus sidewalk cafe.

Bicycle versus taxi cab.

In New York, some of the most heated political struggles do not occur at City Hall, but out in the open - in the city's parks, sidewalks, and streets. These passions intensify each spring as everyone stakes a claim to the limited outdoor space.

Fourteenth century Britain faced a similar challenge (in a case that is cited in economics textbooks as the "tragedy of the commons.") The country was organized into a collection of villages, each with a collectively owned pasture called the commons. Each individual resident was allowed to graze his livestock, which worked fine as long as there was enough space for everyone. But if villagers could not find a way to control population growth, and in some cases greed, the economic system and the town would collapse.

Today, 8 million New Yorkers compete for a share of 309 square miles - only a small fraction of which can be considered public.

This competition sometimes pits humans against animals.

There are an estimated 1.5 million dogs in New York City and only 26 dog runs. Dog lovers argue that pets - and their owners - need space for the city to be livable. Opponents counter that dog runs are smelly, noisy, and a poor use of limited park space.

It extends to the sidewalks, another public place. There are 722 sidewalk cafes in New York City, twice as many as there were ten years ago. The cafes create a vibrant street life and help to bring business and revenue to the city. But residents who live near outdoor cafes complain that they are noisy and clog walkways.

Even the city's public jewels - Central Park and Prospect Park - are not immune.

When Central Park and Prospect Park were designed in the 19th century, the planners tried to minimize tensions between pedestrians and carriages by restricting them to separate pathways. "A carriage coming directly upon the course of a pedestrian or a man on horseback is an annoyance, if not positively dangerous," wrote Frederick Law Olmsted, one of planners. A century and a half later, park officials struggle to live up to that initial vision as walkers, bikers, joggers, rollerbladers, horses, and cars all vie for a lane.

The solutions to these and other local issues often fall to the residents who have the fiercest passions and conflicting notions of what constitutes "quality of life."