It's called London Underline and it is the new project by the global architecture company Gensler that could be soon realized in London, one of the cities with the highest level of traffic and pollutants in the air.
The idea is to transform the old abandoned tunnels of the London Underground in innovative bicycle and pedestrian paths accompanied by cultural and commercial spaces such as shops, restaurants and bars. The London Underline will be accessible directly from the entrances of the subway stations and will have a special focus on the ecological and green aspects: the tunnels are indeed covered with a special floor with Pavegen system that can generate and store energy by exploiting the weight and movement of pedestrians and cyclists, transforming the kinetic energy into electrical energy.
For now, the Gensler team looked at two routes: one that runs from Holborn to the abandoned station of Aldwych and the other one that connects Green Park to Charing Cross, but more minor underground routes could be made. The idea aims to relieve congestion on London's roads and reduce air pollution and has enjoyed immediate success so much that recently the project was awarded to the London Planning Award for 'Best Conceptual Project'.