Femern A/S is the company responsible for planning, construction and operation of the Fehmarnbelt Tunnel. The company is part of the Sund & Bælt holding owned by the Danish state to which also the companies responsible for the fixed links across Öresund and Great Belt belong. The Fehmarnbelt tunnel will be the world’s longest immersed tunnel for road and rail stretching 18 km across the Fehmarnbelt from Rødbyhavn in Denmark to the German island of Fehmarn. The tunnel will comprise a four lane motorway and two electrified rail tracks.