FITTINGLY for a free-trading nation, Britain imports a lot of policy wheezes from overseas. One can now be seen in Exhibition Road, a west London street that contains the Science Museum, the Natural History Museum and the Victoria and Albert Museum. At a cost of almost £30m ($47m) and over three years, this 800-metre-long thoroughfare has been converted into the country's largest "shared space." Road markings and kerbs have mostly gone, and it is no longer entirely clear what is pavement and what is road. The approach, which was pioneered by Hans Monderman in the Netherlands, is supposed to promote safety and ease congestion. Removing bossy signs, traffic lights and the distinction between road and pavement prompts drivers and pedestrians to pay more attention to each other, or so the theory goes. Towns and cities in Denmark, Germany and Sweden have abolished such distractions and reported fewer accidents. In some ways the British version is half-hearted. To reach the South Kensington museums, visitors must still cross a busy four-lane road using traffic lights. In places, bollards have been erected to stop vehicles straying where the pavement would be. Ranks of bicycles available for hire and parked cars clutter the street. The road surface itself is not completely flat: following a legal challenge mounted by Guide Dogs, a charity for the blind, the Royal Borough of Kensington and Chelsea was obliged to install ridges where the kerbs used to be. And the kerbs themselves reappear at bus stops, to enable step-free access. Still, it seems to be working. Only a few minor accidents have happened since the road opened. The museums are doing a roaring trade. New restaurants offering alfresco dining appear to be thriving. The hordes of tourists - some 11m people visit Exhibition Road each year - express delight at the shared space. In continental theory, shared spaces work because walkers, cyclists and drivers acknowledge each other, making eye contact and negotiating the use of the street. Not quite so in Britain. Steve Melia of the University of the West of England has studied how people move in another of the nation's shared spaces: Elwick Square in Ashford, Kent. He found that most pedestrians skirt round the parts used by vehicles. Instead shared spaces seem to work for a different reason: drivers avoid areas that attract lots of visitors on foot. When New Road in Brighton, which runs alongside the Royal Pavilion, was converted, vehicle numbers fell by 90%. Traffic engineers reckon that 30% less cars and lorries are now using Exhibition Road than did so before the change. Queen's Gate, which runs parallel to it, is jammed.