The 3km line will branch off the Cityringen near Østerport with a single intermediate station at Orientkaj serving the ferry terminal and UN offices. When it opens in 2019 the branch will become part of line M4, and is initially expected to carry around 11,000 passengers per day, rising to 40,000 passengers per day as further residential developments are completed in Nordhavn.

The project team will be responsible for the design of the tunnels and rail systems, as well as the elevated station at Orientkaj and underground station at Nordhavn. Architect Cobe will act as sub-consultant on the project.