These bridges were made for walking In London's Docklands, Peter Murray sees an exhibition of designs that span the gap between beauty and functionality

Just as the chair was the design icon of the Eighties, so the bridge is fast becoming the image of the Nineties. The continuing development of London Docklands, although this might have seemed a purely Eighties phenomenon, continues to offer cons iderable scope for this image to be explored and redefined - as an exhibition, Building Bridges, at the Architecture Foundation, London makes clear.

Since its formation in 1981, the London Docklands Development Corporation (LDDC) has, painfully slowly, been creating an integrated infrastructure for the area based around a road network and public transport system that is, in turn, shaping a loose-grained urban environment with a pedestrian and cyclist network - enhanced by bridges across water and roads - which brings the beefy Docklands environment down to a human scale. The LDDC has organised a series of competitions for the design of these new bridges. The results show that these small-scale projects seem to encourage architects and engineers to produce their best work in a part of London where structures on a titanic scale have ruled the roost.

"In the two competitions so far," says Cynthia Grant, the LDDC's director of transport, "we have tried two different approaches. In one we invited engineers to lead the design team and in the other architects. We decided that the third and final competition, for the Royal Victoria Dock, should be architect-led, as we believe the solutions will be more innovative."

It is appropriate that the last decade, which celebrated the individual, should have been identified with the chair - an object that is essentially egocentric. You are unlikely to find exhibitions of arty new chairs in the Nineties. Bridges, unlike chai

r s, bring people together: they join places and they represent an idea of community in a period in which the individual, privatisation and deregulation - the breaking of communal bonds - have held sway.

The Coalbrookdale bridge (Ironbridge, Shropshire) celebrated, in a strikingly elegant style, the achievements of both 18th-century ironmakers and the Industrial Revolution. The Clifton suspension bridge spanning the River Avon sings of Brunel's daring a

n d the harmony of architectural form and engineering function. ThePont Neuf, Paris, the Ponte Vecchio, Florence, the Golden Gate bridge, San Francisco and Sydney Harbour bridge all stand as energetic symbols of the cities they adorn.

Despite the importance of the bridge, much of the work in the last 50 years in Britain has lacked originality. "An engineer who doesn't give a damn what his bridge looks like as long as it works and is cheap, who doesn't care for elegance, neatness, order and simplicity for its own sake, is not a good engineer,'' said Ove Arup, the great Danish emigre engineer. Such unimaginative engineers have been able to build far too much. The Department of Transport's record as design patron, for example, is by an

d large execrable.

Arup, who died in 1988, greatly influenced engineering design in Britain by encouraging a closer relationship between design disciplines. His own design for the Kinsgate footbridge in Durham is a graceful essay in reinforced concrete. A U-shaped walkway is supported on filigree fingers of beton brut as it spans the River Ware; the expansion joint in the centre of the bridge looks more like a Barbara Hepworth sculpture than matter of fact engineering, but function it does, pointing to a new freedom in bridge design.

The one designer probably most responsible for promulgating this as yet still new message is Santiago Calatrava, the Spanish architect-engineer well known for many beautiful bridges on the Continent as well as for the design and engineering of the stunning TGV station at Lyons Satolas airport in France. His bridges do not merely span two points, they make a statement about the very act of crossing - you do not cross a bridge by Calatrava and fail to look at it.

While sophisticated in their engineering, his designs are readily accessible as popular images; their anthropomorphic skeletal elements are composed in sweeping curves that create a true excitement.

Calatrava was commissioned by Stuart Lipton, the London property developer, to produce an alternative design to that proposed by the Department of Transport for the East London river crossing in Docklands. Calatrava's design was a thing of elemental beauty, in sharp contrast to the DoT's lumpen efforts. The design was not taken up. Still, Calatrava's spirit has been taken up on a smaller scale by British architects and engineers responding to opportunites for bridge design in Docklands.

In Docklands, the patterns of water were set out for great ships. They maintain their grandeur still, but the LDDC's programme of bridges is intended to humanise an old industrial area built on a heroic scale. It is aimed, too, at encouraging pedestriansand cyclists, and brings together the divided pockets of Docklands.

The bridges will make a strong visual statement; markers for our passage through what is still a baffing urban environment, and small-scale monuments to be enjoyed rather than passed over and ignored.

`Building Bridges: new pedestrian bridges for London's Docklands', until 26 February, Architecture Foundation, 30 Bury Street, London SW1, 071-839 9389.