Architecture: No lovers, no mopeds, no smiling after 8pm. It's time to step on the cult of the pedestrian

The announcement last week of plans by Sir Norman Foster to make life better for pedestrians as they make their way from the National Gallery in Trafalgar Square to Westminster Abbey sparked off a small, yet significant debate in the media. There are those who support the idea of "pedestrianisation" and those to whom it is one of the evils of our age along with superstores, edge-of-town development, executive cul-de-sacs, light pollution and theme parks.

Cities, say the anti-pedestrianisation lobby, have everything to gain by the rush of life, the frisson of danger and the intensity that traffic, of all kinds, brings with it. Take away traffic and city centres become husks, devoid of life, carpeted in litter and littered with banal "street furniture" in the guise of heritage-style lamps, benches, litter-bins, "planters" (those sad brick oblongs into which people deposit sweet-wrappers, cigarette ends, fast-food cartons, sick and squashed soft-drink cans). Take away traffic and we are left with pedestrian squares and streets, in Britain at least, that never quite seem to match those of Siena or Rome. The cafes are not so stylish, nor (shame on us) the people. No old men in natty suits and hats playing draughts or dominoes around even older tables. Surly waiters instead of smart ones. Hideous brick paving where there should be York stone or granite. Backpackers in Day-Glo travel-wear and coach parties of sheep-like tourists instead of beautiful young locals buzzing in and out of Baroque squares on Vespas. No sculptural, blood- red motorbikes propped up beside fountains festooned with lascivious nymphs and goaty Tritons blowing wreathed horns.

The detractors have a point, and a good one. Recently I was in King's Lynn. The heart of this nautical town has been pedestrianised (brick pavements, sad "planters" and so on). When the sun went down, the pedestrianised streets died with it. Utterly devoid of signs of life save for those of my footsteps and the pattering of the dog's paws alongside me. Completely heartless. Not a place you want to walk on your own. And, yet, a couple of hundred yards away, traffic confined to the arterial roads that ring the old town, roared in pent-up anger. Almost unbelievably, having walked in solitude in the town centre, it was hard to cross these artificially busy roads to reach the forlorn railway station.

The same experience can be had in all too many British towns. Pedestrianisation sounds noble in principle, but the truth is that, unlike Romans, we do not make much use of pedestrian streets and squares except during shopping hours, and we certainly don't enjoy them. Where are the cafes and fountains, the old men in natty hats playing draughts, the gorgeous girls and handsome boys on their scooters? They exist only in the "virtual" world of architects' drawings in Britain.

The fact is that few people live in British town centres any longer. The lure of the brand new Tudorbethan villa, the contents of the deep- freeze, excruciating dinner parties and the spice of soap-operas, is more than a match for the charms, potential or real of the town centre. People will only make full use of pedestrian squares and alleys either if they live nearby or they scent the promise of entertainment and excitement. The hoary old excuse that the British climate is unsuited to enjoying life outdoors was always a silly nonsense and never more so than now as these islands learn to forget what rain was (London has been dry for weeks) and to bask in ultra-violet heat. We prefer to watch beefy sport on telly, six-pack to hand, than to stroll arm-in-arm along corsos, viales and piazzas.

And when we do pedestrianise, we impose miserable by-laws created by control-freaks on the areas affected. Dogs must be on leads. No mopeds or motor-scooters. No smiling after 8pm. Glamour strictly prohibited. Pedestrianisation will never make sense while we continue our national hate-affair with the town and city centre, while we insist on being passive, "customers" of UK plc rather than active citizens of vibrant towns and cities. Until we learn to love our cities and make full use of them, we must be careful not to strip them of what life they do have, no matter how elegant the plans drawn up by well-intentioned architects and planners.