The project involves a 18 km long tunnel that will have its starting points in the towns of Rødby, in Lolland, and Puttgarden, in Fehmarn. The tunnel will rest on the bottom of the strait that geographically divides the Bay of Kiel from the Gulf of Mecklenburg. Its construction involves the creation of an excavation, the maximum dimensions of which are 60 meters wide and 16 meters deep for 18 km of length. The excavation houses the box-like structures, prefabricated on site on the mainland, within which vehicular and rail traffic will flow.
All these characteristics will make the Fehmarn Belt tunnel, once completed, the longest underwater connection of its type in the world.