By Harriet Festing

Water is a great liberator. Sunbathers dip their toes in it, passers-by dangle their fingers in it, and - if they're lucky - kids run into it - the bottoms of their trousers soaking up the drench.

Benches, too, have this affect. There's the youth who leave cigarette butts on them, sleepers who lounge with smelly coats, and old ladies who won't budge.

But kissing is the true sign of liberation. Lovers like to do things prominently, in a mood of egalitarian bliss, when the sun is warm and the whole world is watching.

You can tell when things are heating up; arms slink over shoulders, old men squeeze their wives' knees, and couples intertwine their little fingers. Ice-cream licking is another sure sign. Long slow licks that lap up dribbles on a hot summer's day.

Liberty is not an inevitable consequence of public spaces.

All of which leads me to wonder how London will manage with its 20% decongested, newfound freedom in the public realm. A pedestrianized Trafalgar Square, promises of a world-class park along the South Bank, and Livingston's plan for 100 public spaces - how will our straight-laced officials cope with the informality?

Liberty, I quickly add, is not an inevitable consequence of public spaces. Take a look off London's city roads, and you'll see parks and squares galore that have nothing happening in them at all. Indeed, with so little usage in our existing spaces, one could wonder why there's been such enthusiasm to add more.

It was this same issue that inspired research in New York City in the 1970s. In a city where space is so precious, the researcher - William H. Whyte - devoted 3 years to finding out why some places were jam-packed, while most remained empty.

There were financial reasons for figuring out the problem. At the time of the study, the city gave incentives to builders to provide plazas. By 1972, New York had 20 acres of the most expensive public spaces in the world. "The city was being had" noted Whyte "For the millions of dollars of extra space it was handing out to builders, it had every right to demand much better plazas in return."

Whyte's lessons are printed up in the now classic book and video 'The Social Life of Small Urban Spaces.' Together, the publications create a handbook of what makes places work, or fail.

So what makes a place popular?

The main answer is 'other people'. Although most people say they want to "get away from it all" and "escape," their actions show the opposite: they stand and converse in the main pedestrian flow, sit in the heart of the action, and take seats in the front (men) or second to front (women) of a bustling area.

People like places that they can make their own; places that they can shape, mold and influence.

People also sit most "where there are places to sit". Not an intellectual bombshell, admits Whyte. Clearly, even the most attractive fountains and striking designs cannot induce people to come and sit, if there is no place to sit. Sun, trees, water, food and the relationship between street and space become secondary factors.

But the real message from the black and white footage of Whyte's filming lies in its subtleties. The dabbling of a foot in the water at Seagram's plaza; two wide-eyed girls running up the steps at Paley Park; and the purposeful grace of a group of men carrying, positioning and re-positioning chairs at Greenacre. Whyte's delicate - almost sensual - portrayal is subversive.

The point is that people like places that they can make their own; places that they can shape, mold and influence. And most public spaces are heavily controlled; by designers who create paths where no-one wants to go; managers who won't let you touch the water; and by the lack of imagination of the people who put the space there in the first place.

So when Paris converted 3.8 km of inner-city expressway into an urban beach, what was significant is what they put in its place: 80 imported palm trees, 22 blue and white striped changing tents, 150 parasols and 300 blue canvas deckchairs. There was more, too: a string of cafes, music and dance floors, climbing walls and pitches for volleyball, boules and golf practice. Three million people visited the Paris-Plage in its first week, 600,000 on the first day alone.

New York also has some of the best-loved public spaces: hot-dog sellers, roller-bladders and jaywalkers, all components of a city in mild disarray. As one travel guide so aptly puts it: 'When it comes to throngs, controlled chaos and in-your-face audacity, the Big Apple ranks right up there with Hong Kong and Mexico City. When it comes to opportunity and adventure, this apple is uncontested.'

The Millennium Dome failed to capture the imagination of the people, because it wasn't designed for them in the first place.

Back in London, I'm reminded of how the government dreamed up the Millennium Dome - a monumental shell - without knowing what to put in it. The Dome failed to capture the imagination of the people, because it wasn't designed for them in the first place.

The cost of Trafalgar Square's improvements is £25 million; a park along the South Park is estimated at £7 million. Will these also be shells? Or perhaps they are the beginnings of a newfound freedom in the city? Your guess is as good as mine.

Meanwhile, next time you see a couple kissing in public, don't lynch them. Their embraces are the best indicators yet of a public investment well spent.

This article originally appeared in The Independent on Sunday, June 8th, 2003.