London, England (CNN) -- Six thousand matching black, silver and blue bicycles are about to hit the streets of London on Friday as the city launches an ambitious public bike sharing scheme.
The initiative will allow commuters and tourists to take bikes from 400 docking stations, spaced at 300 yard intervals, for short journeys around central London.
For an access fee of £1 a day or £45 a year, cyclists will be able to use the bikes for free for the first half hour, with a rising fee for longer periods. Users can return for further free half hours as often as they like within a day.
The scheme has cost £140 million for the first five years, with £25 million recouped from Barclays Bank sponsorship.
The launch is a major step forward in Mayor of London Boris Johnson's ambition to increase cycling in the city by 400 percent between the years 2000 and 2025. An estimated 500,000 journeys a day are already made by bike in the British capital.
Kulveer Ranger, the Mayor's Transport Advisor, told CNN that the scheme had been one of the Mayor's key aspirations since he was elected two years ago. Members of his team visited cities around the world to make sure that lessons were learned from other schemes.
"This will change London forever," Ranger told CNN. "We want these bikes to become icons of London just like red buses and black taxis. We think London will be proud of these bikes, giving everyone an opportunity to use the cleanest, greenest form of transport.
"Undoubtedly there will be teething problems, but going forward we will have the best cycle hire scheme in the world."
Ranger said the bikes had been designed to cover 60,000 miles over their 15-year lifetime, spending 24 hours a day, 365 days a year on the streets in rain and shine.
He said a fleet of electric vehicles would re-distribute bikes if they ended up with too many at popular drop-off spots. In Paris, bikes famously bunched at docking stations at the bottom of hills, as no-one wanted to cycle them back up.
Johnson, a keen cyclist, said in a video message on Transport for London's website: "Not only will [the scheme] benefit the individual using the scheme but it will also reduce demand on crowded buses and tubes by relieving congestion."
The Mayor also recently unveiled London's two new wider blue "cycle superhighways," with mirrors and extra space at traffic lights. Ten more are planned by 2015.
The cycle hire scheme in London will follow the Velib scheme in Paris which launched three years ago with 10,000 bikes, rising to 25,000 now.
When it was launched, Paris was by far the largest scheme in the world, although it has since been overtaken by Hangzhou, Beijing and Shanghai in China.
Paul DeMaio, a bike sharing blogger and founder of the consultancy MetroBike in Washington DC, said Paris had the first large-scale technological scheme, although it had its forerunners.
"The first program started in 1965 in Amsterdam in the Netherlands with donated white painted bikes left on street corners, but with no control or maintenance.
"Then Copenhagen operated a coin-deposit scheme in 1995 with formal stations, but no technology.
"It is since the third generation launched in Paris that the idea has really caught on. Bike sharing schemes are green, great for the environment and people's health, and ease congestion on other modes of transport.
"I'm particularly impressed by London's scheme. They have gone about it in just the way it needs to happen."
Tom Bogdanowicz, campaign and development manager for the London Cycling Campaign, was given the opportunity to test the bikes prior to release.
He told CNN: "I have ridden the bikes and they are quite nice. You won't be winning the Tour de France on them, but they are sturdy and ideal for cycling around town.
"They're more advanced than the Paris bikes and easier to dock, so they shouldn't have the problem they had there where they didn't dock properly and then other people took them.
"This is a big step forward in encouraging cycling in London. Surveys tell us that one in three people are interested in cycling and this is their opportunity to try it out."
Lessons learned from other cities include making the first half hour's hire free, bikes that are easy to use and difficult to damage, and the need for docking stations to be close together.
Transport for London is hoping to have 15,000 registered users by launch day.
Casual users will be able to use the scheme about four weeks after its launch.
