SkyCycle is a proposed transport infrastructure project for London of a 219-kilometre (136 mi) network of elevated cycle paths above train tracks. The routes would have a width of up to 15 metres (49 ft), and be accessed by over 200 ramps throughout the city, subject to a toll of £1. The developers of the project estimate that the cycle paths would accommodate 400,000 riders during rush hour and shave 30 minutes off current travel time. If the project becomes a reality, its construction is estimated to take over 20 years. The project is the creation of landscape architects Exterior Architecture and Space Syntax, with whom Norman Foster of Foster and Partners has been working since 2012. The proposals were welcomed by Network Rail.