NEXT month a so-called "brand new means of transport" will be launched in Copenhagen: the bicycle. GoBike, Europe's latest bike-sharing scheme, will have bicycles with built-in tablet computers that direct cyclists to the best local restaurants, show offers in nearby shops and give the latest train times. Bike-sharing is shifting up a gear: it seems that nearly every self-respecting mayor is either developing a scheme or announcing an expansion to one. What is the impact on cities' development? Bike-sharing began in the 1960s when 50 "free bikes" were scattered around Amsterdam. They were promptly stolen. But after this slow start bike-sharing has blossomed. Over the past decade the number of schemes has increased tenfold. Bike-sharing ventures now exist in more than 500 cities, from Dubai to Hawaii. Each works on the simple principle that a user can borrow a bike at a docking station and then return it to another. The first 30 minutes are usually free. The most successful schemes have large fleets of bikes, lots of small docking stations and a few "superdocks" in busy places, such as train stations. Electronic monitoring of the bikes can show ebbs and flows of bike traffic through cities, allowing better distribution of bikes and planning of new docks.

Just as mass public transport changed the development of cities' suburbs, bike-hire schemes are now shaping city centres in subtle ways. A "cycling census" in London found that in the morning rush-hours nearly half of all northbound traffic crossing three of the city's main bridges was made up of cyclists. Planners have responded by criss-crossing the city with cycle-paths; more are proposed. Some mayors are experimenting with bike-only days: Mexico City, the unlikely home of a highly popular bike-hire scheme, closes its central eight-lane highway to cars every Sunday, to the rage of motorists. Property developers are taking note, too: just as houses near metro stations tend to command higher prices, research now suggests that access to cycle paths and proximity to docking points is linked to higher rents. Finally, bike-sharing opens up parts of cities that were previously hard to access by public transport, especially late at night when bus and train services get thinner. Research by Susan Shaheen at the University of California, Berkeley, found that in Montreal and Toronto four out of ten people shopped more at locations near bike stations. In Washington, DC, more than eight out of ten said they were more likely to visit a business, shop or restaurant with easy access to bike-sharing dock.

Just as researchers begin to grasp the impact of bike-sharing, the schemes themselves continue to evolve at speed. New developments include much cheaper "dockless" bikes, already in use in Berlin, which can be found by mobile phone. Another promising development is the introduction of electric bikes, for longer or steeper journeys. Such innovations could help broaden the appeal of bike-share schemes beyond their current users, who are mainly young, relatively well-off men. Bike sharing is just one part of a broader movement towards alternative forms of transport in increasingly crowded cities, but it could be an important one. As last year’s United States Conference of Mayors concluded: "communities that have invested in pedestrian and bicycle projects have benefited from improved quality of life, healthier population, greater local real-estate values, more local travel choices, and reduced air pollution." Time for more of the world to go Dutch.