London's Abandoned Tube Tunnels Used as Bike Lanes

During the construction of the intricate London Underground system, the developers left many completed stretches of tunnel unused. London-based architecture group Gensler is exploring the idea of turning the defunct access ways into routes for cyclists and pedestrians. Titled The London Underline, Gensler believes there is a ”greater pressure on infrastructure” due to the city’s ongoing rise in population. To read more about London’s development plans, head over to Fast Company.