Plans for a network of cycle pathways high above London's railways have been unveiled by architect Sir Norman Foster.

SkyCycle's ten routes in a series of three-storeys-high paths will be used by an estimated 12,000 cyclists per hour. The project will cost around £220m.

The bicycle network will allow cyclists to raise their average speed from 10mph to 15mph in the city, hopefully protecting their lives and cutting journey times.

Sir Norman Foster, who designed St Mary Axe, known as 'The Gherkin', and the new Wembley Stadium, said: "'Cycling is one of my great passions – particularly with a group of friends. And I believe that cities where you can walk or cycle, rather than drive, are more congenial places in which to live.

"To improve the quality of life for all in London and to encourage a new generation of cyclists we have to make it safe. However, the greatest barrier to segregating cars and cyclists is the physical constraint of London's streets, where space is at a premium. SkyCycle is a lateral approach to finding space in a congested city."

The developers, Exterior Architecture, Foster + Partners and Space Syntax, claim the scheme, built over a period of 20 years, would be much cheaper than constructing new roads and tunnels.

The London cycle network scheme has been compared to New York's High Line, although in the States, it is mainly pedestrian and primarily for tourists and uses converted disused railway lines.

The first phase of SkyCycle is a four mile stretch from east London to Liverpool Street Station and commuters can expect to pay £1 per journey.

Over the last ten years, cycling has grown by 70% and on major roads the number of cyclists has increased by 173%.

Road safety for cyclists is a major factor. Between 2006 and 2011, the number of cycling casualties rose by 50%.