The Mayor of London, Boris Johnson, has an ambition to make London as cycling-friendly and safe for cyclists as cities such as Copenhagen.  This is quite a challenge, given the physical constraints of the road network that London has today.  It will need a mixture of large scale and minor interventions.  Lord Foster has entered the debate with a proposal for a bold series of dedicated cycle paths, three storeys high, that would enable the cyclists to have their own safe routes.  SkyCycle is a 135-mile network of roads proposed to be constructed above existing suburban rail lines to create new cycle routes throughout London. The three-storey high routes would be accessed via ramps at more than 200 points and the first phase would be a four mile stretch from east London to Liverpool Street Station at an estimated cost of £220m. Each of the 10 proposed routes could accommodate 12,000 cyclists per hour and improve journey times by up to 29 minutes and would be less expensive than other options such as tunnels.

This is a welcome addition to the debate about the design of future sustainable transport for London.