Thinking on street design has changed radically in recent years, moving from a view that different kinds of street users should be kept separate, with priority given to vehicles, towards more integrated designs that put the pedestrian first.
This sounds fine in theory. But the growing trend for removing boundaries altogether between pedestrians and vehicles - known as "shared space" - is attracting criticism, including from the very people it was supposed to benefit.
The design approach began to appear in the Netherlands around a decade ago, where it had been popularised by a Dutch road traffic engineer, the late Hans Monderman, and it is currently being promoted at EU level. Its influence in Britain now appears to be spreading rapidly, with - by one estimate - around 100 examples completed or in construction or planning.
These have ranged from small, localised examples such as at the Seven Dials junction in London's West End to larger schemes such as Whitelaw Turkington's design for the former ring road in Ashford, Kent, which opened last year.
But the Guide Dogs for the Blind Association, now known simply as Guide Dogs, is currently running a campaign called Say NO to Shared Streets, to urge designers, planners and authorities to rethink designs.
"There's nothing as safe a delimiter as a kerb," says Guide Dogs representative Vicky Bell. "They make the rules of the road clear."
She rejects the claim that shared spaces reduce the likelihood of accidents. "Blind and elderly people in the Netherlands say they simply avoid these areas - they're too scared to go there," she says.
Guide Dogs has also looked more generally at the issue of safe road design, she says, and is happy to see street furniture removed. "We don't have a problem with de-cluttering - it's good to have fewer obstacles for blind and partially-sighted people on streets."
Guide Dogs claims to have the support of 28 other organisations such as the RNID (Royal National Institute for Deaf People) and Scope. It has been targeting local authorities - "they have a duty to talk to users" - along with designers and planners.
"Results have been mixed," says Bell. "We have had some success - local authorities have changed schemes or have scrapped them altogether. But we still have some work to do."
She cites Dixon Jones' £25m redesign of Exhibition Road in South Kensington, London, where work is currently underway, as a partial success. "They have made some changes, but it still doesn't feel safe enough," she says.
At nearby Sloane Square, a 13m stretch of road in front of the Underground station has already been converted to shared space at a reported cost of £300,000. Despite a demonstration by Guide Dogs, together with the West London Residents Association and the TaxPayers' Alliance, the scheme opened in February this year.
Since then, according to one regular vendor at the site, one pedestrian has been hit by a cyclist and another by a Post Office van within the short stretch.
Interaction over regulation
Architect Ben Hamilton-Baillie, a former colleague of Hans Monderman, claims to have coined the term "shared space" in 2003. He is angered by the Guide Dogs campaign.
"They are a very well-funded organisation, so the debate is couched in terms of their campaigns," he says. "But they are just one of dozens of important user bodies."
He believes Guide Dogs should be an ally of the design approach. "It works by interaction rather than regulation and control, which Guide Dogs in fact supported," he says.
"We are seeking the same thing, which is safety in the public realm. The question is how to make it safer and easier to get about, and critical to that is the question of traffic speed, which then overrides everything else. Does shared space help to slow traffic down? Early findings show that it does."
And he believes existing examples of shared space design in Britain show the approach "has been a very effective way to reduce speeds". "You need a lot of time to see how it affects safety," he says.
"But in places like Ashford there is no evidence of an increase in accidents. Though as to whether it puts people off using the spaces, that's very hard to measure."
He adds, though, that success can already be claimed for schemes such as Kensington High Street, where pavement-mounted barriers and other "clutter" has been cleared away. "It has increased awareness between drivers and pedestrians and lowered accidents by around 60 per cent," he says.
Hamilton-Baillie is confident of the approach having a future in British street design. "The quality of our streets generally isn't great," he says. "But a lot of highway authorities across Britain and Europe are interested in this."
The Landscape Institute "does not have an official view" on shared space, according to a representative, though it devoted the current issue of its Landscape magazine to debating the approach.
But CABE Space, the Government's advisory body for public space design, has its reservations. Streets adviser Louise Duggan provides critiques of designs, often as part of larger urban design masterplans.
"CABE believes in streets designed for people, that make pedestrians feel equal to other road users," she says.
"In the past we have tended to design streets from the technical side, but the social aspect of streets is very important. Streets make up around 80 per cent of public space, so by neglecting them we are potentially missing out on opportunities.
"But we feel that shared spaces, particularly shared surfaces, haven't quite cracked how to deliver full inclusion. There are issues that need to be addressed, especially where blind people are concerned.
"However, we are also conscious of the good they can deliver. They are still emerging but are more than just a fashion - there are many potential benefits for different user groups. We don't want to throw the baby out with the bath water."
REVIVING CRAIGMILLAR'S STREETS
Well away from Edinburgh's tourist hot-spots, the district of Craigmillar on the south side of the Scottish capital has become a byword for social problems.
The ParcLife project, a joint venture between the City of Edinburgh Council and regeneration agency EDI Group, is attempting to revive the area with innovative designs in housing and public space including, in the Greendykes area, the use of shared space.
"We chose landscape architects for the street design rather than road engineers," says EDI Group senior development planner Will Reid. "Craigmillar has the worst health in Scotland. We have to prove that what we put in has social outcomes in terms of health or education."
Halcrow landscape architect Emily Yates began her involvement in the Greendykes area four years ago. "It's unusual for a landscape architect to be leading a design team on a project like this," she says. "It's lovely to see quality going into the public realm, though it's a challenge for the sales team to explain the added value to customers."
Dutch street design was a major influence - so much so that councillors were taken on a study trip to the Netherlands in order to be convinced.
The first houses in the shared space area are now on the market. "It will be interesting to see how it develops and how people respond to it," says Yates, though she adds that subsequent stages are "on hold due to the economic climate".
On the Guide Dogs campaign, she says: "I am very disappointed in it, because the whole point of shared space is to give priority to pedestrians - cars have to give way.
"Anything that makes the driver think is a good thing, and that's what this is designed for. Every 25 metres there's something - a chicane, parking in middle of the road - so you're constantly having to think and to slow down.
"Clearly it's going to take a bit more consultation, education and information-giving. But more schemes like this will increase people's confidence."