One of the world's top architects has unveiled plans for an ambitious network of cycle routes high above London.
Lord Foster, who designed London's "Gherkin" tower, wants to construct 135 miles of bike routes above the capital's main rail lines.
He said it would be "a lateral approach to finding space in a congested city."
Cyclists would be able to get access to the "SkyCycle" routes at more than 200 entry points across the city, riding into the centre avoiding the congested roads below.
First up would be a four-mile stretch linking east London to Liverpool Street Station, costing £220m.
“Cycling is one of my great passions — particularly with a group of friends," said Foster.
"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 plans have already been presented to Boris Johnson, who has asked for more details of the cost, the Sunday Times reported.