A groundbreaking engineering project is underway to connect Denmark and Germany. The Fehmarnbelt Tunnel will be the world’s longest road and rail tunnel. Spanning 18 kilometres (11.2 miles), this ambitious undersea structure promises to reshape European transport forever. It will significantly enhance travel efficiency and connectivity between the two countries.
The tunnel will feature two lanes for road traffic and two electrified rail lines. It will sit beneath one of the busiest shipping lanes globally. Unlike traditional tunnels, the Fehmarnbelt Tunnel will use prefabricated concrete sections. These sections will be floated to the seafloor, linked, and then submerged in a trench. This innovative method is designed to expedite construction while ensuring safety.
Currently, the Fehmarnbelt Tunnel is under construction with an estimated cost of €7.4 billion ($7.7 billion). The first precast concrete sections were completed in February 2025. Each section is massive, measuring 217 metres long and weighing about 73,000 tonnes. The project aims to reduce travel time from a 45-minute ferry ride to just 10 minutes by car and 7 minutes by train.
Moreover, the tunnel is expected to boost tourism in the region. Visitors will enjoy easier access to Scandinavia for weekend getaways. However, the project faces environmental challenges. Femern A/S, the company managing the tunnel, is committed to addressing these concerns. They aim to create new natural areas to offset any negative impacts. Once completed, the Fehmarnbelt Tunnel will transform transport in Europe, benefiting both people and goods.