All the pavement artists in Trafalgar Square congregate on the strip in front of the National Gallery. This is because the rest of the square is managed by the Greater London Authority, which won't allow their activities. The northern terrace — a roadway until it was pedestrianised in 2003 — is still managed by Westminster council.
This is part of the madness surrounding the way we are allowed to use the London landscape — the city's squares, roads, pavements, riverbanks and all the bits between the buildings. Their use is explored in Public London, an exhibition by New London Architecture (NLA) at the Building Centre in Store Street WC1.
The show tracks the largely positive change in attitude towards public space in the capital in the decade since the city was awarded the 2012 Olympics. But the show's organisers, NLA's chairman Peter Murray and director Debbie Whitfield, say the debate about public space began much earlier when, in 1986, architect Richard Rogers first suggested pedestrianising Trafalgar Square, Parliament Square and the whole of Victoria Embankment, which would be turned into a park with the traffic sent underground.
These radical ideas drove subsequent discussions with governments and mayors. Meanwhile, developers had begun to include areas that were ostensibly public in commercial schemes, such as Broadgate in the City and in Canary Wharf. Research found that office workers are prepared to walk up to 440 yards further at lunchtime if they can find a nice place to sit and eat their sandwiches or chat with friends. Landlords soon realised that friendly and welcoming public spaces outside their buildings would attract more tenants and customers.
The show begins outside the NLA's Store Street offices, where the curved forecourt-cum-road is turned into an installation called Never Mind the Bollards. All the items making up this urban environment — plane trees, cobbles, manhole covers and lamp posts — will be annotated to get people thinking about the spaces we share.
The NLA had previously simply laid AstroTurf on its forecourt, which was immediately populated by lounging Londoners. "As soon as you give people something to sit on, they come from all around to use it," says Murray. "Londoners are desperate for outside space where they can have a sandwich and meet their friends."
Fifteen years ago, Westminster council threatened to prosecute cafés that put tables on the pavement — now café culture is seen as an essential part of street life. Just look at Soho. The conversion of Exhibition Road in South Kensington into a fluid "shared space" is a recent example of friendly space.
Smaller projects include Assemble — a timber stage in New Addington town centre, built as a focal point for community events — and the proposed floating lido on Victoria Embankment, planned by Studio Octopi.
In my bit of Lambeth, grass bays and flowerbeds have been built out into roads, helping drainage, slowing traffic and making life that little bit more pleasant. Many improvements involve transport upgrades and changes to road usage.
The congestion charge was a major game-changer for the quality of life in London, as was the reintroduction of slower, more pedestrian-friendly, twoway traffic in place of one-way urban "race tracks". This transformation is due for Tottenham Court Road and Gower Street. City Hall and TfL are currently organising London's roads into nine categories, from arterial routes where vehicles can travel at 60mph down to pedestrian zones.
In 2018, Alfred Place, off Store Street, will be converted into a park in time for Crossrail. The new link will mean thousands more people on the pavements in the West End and the City. Murray says: "We need to think about how we provide space for them to move around comfortably." Hence the creation of a proper piazza around Centre Point.
"One of the biggest mistakes Boris Johnson made was to abandon the pedestrianisation of Parliament Square for God knows what reason," adds Murray. "But that will come back on the agenda because it really is a scandal." Richard Rogers's plan for a park on Victoria Embankment never came true, although "it is going to be a cycle superhighway, so less car dominated".
With expected local and central government spending cuts, the creation and maintenance of public space will inevitably fall to private developers. And there is an ongoing debate about how "public" the spaces should be.
Murray says, however, that things are improving. Security guards at the More London development no longer treat passing cyclists as if they are terrorists. Murray adds: "There is still work to be done, but the open space debate is all going in favour of more sandwiches being eaten outside in summer."
Public London: Ten years of transforming London's public spaces is at the NLA Galleries in the Building Centre, 26 Store Street WC1, until July 11 (www.newlondonarchitecture.org)