The ambitious idea, dubbed the London Underline and formulated by architecture firm Gensler, looks to provide an answer to the city's overcrowded roads and transport options. The project would even harness the kinetic energy of people's footsteps and turn it into electricity that would be used to provide power (e.g. for lighting) in the tunnels and allow the project to potentially become carbon neutral, while the team would envision creating a whole subterranean world featuring shops and cafes.
The idea earned its creators, architecture firm Gensler, the London Planning Award. The team highlighted the need for innovative thinking to solve London's mobility issues, stating "With current pressures on London to cope with future transport capacity for pedestrians, cyclists and tube users, London is in desperate need for new types of public and community space, as well as affordable retail, commerce and entertainment spaces. Subterranean spaces present an excellent option for new uses."
Under the current proposal, the project would make use of the disused Piccadilly Line branch that stretches from Holborn to Aldwych station while Green Park would connect to Charing Cross via a tunnel that was once used on the Jubilee line.
There is perhaps an argument to be made that sending cyclists and pedestrians underground does not exactly fit with an idealised model of urban mobility (whereby those getting around on foot or two-wheelers can do so in fresh, open air), however the project does offer a rather solid solution to London's commuter and traffic congestion problem.