The transit agency Movia has projected that up to 34 million passengers eventually switch from buses to using the Metro during each year.

Due to its success, during 2005, plans were put forward for further expansion of Copenhagen Metro in the form of the City Circle Line.

The planned City Circle Line would connect into the Kongens Nytorv and Frederiksberg stations of the preexisting metro network.

[7] On 7 January 2011, the civil engineering contract for the City Circle Line was awarded to the Copenhagen Metro Team (CMT), a joint venture comprising Salini Impregilo, Technimont, and SELI.

[7] Consultancy services regarding rolling stock and the automated train depot were sourced from Ramboll and WS Atkins.

The interior walls of the tunnel have been coated with concrete and multiple emergency shafts have been installed for the purpose of providing ventilation and maintenance access.

[8] During the construction process, it was commonplace for geological sensors to be deployed in the general vicinity to monitor ground movements for the purpose of protecting buildings and other structures in the city.

[4] It crosses the M1 and M2 lines at Kongens Nytorv and Frederiksberg stations, and suburban train services at København H, Østerport and Nørrebro.

[citation needed] The finished City Circle Line has been promoted as playing a heavy influence upon much of Copenhagen's current transport network.

[10] Once the line is completed, 85 per cent of all homes, work places and educational facilities in Copenhagen's inner city area, as well as the surrounding neighbourhoods, shall be less than a ten-minute walk from either a metro or train station.

[7] It is fully automated, being operated using a driverless system that provides 24/7 service coverage and at a peak frequency between trains of 100 seconds.

[13] While these vehicles are broadly identical to the ones running on the Copenhagen metro, they feature several advancements in technology, materials and design.