A20 Construction Resumes Near Bad Segeberg After 17-Year Legal Battle

Construction of the A20 in Schleswig-Holstein has been a stop-start affair. Only 39 kilometers of the planned 112-kilometer route in the state have been completed so far. The last section before Bad Segeberg was finished in 2009.

In 2013, the Federal Administrative Court halted further construction following a lawsuit by environmental groups, including the BUND. The legal dispute centered on the protection of local bat populations, particularly in the Bad Segeberg limestone caves.

The Bat Compromise

A breakthrough came in November 2025, when the state government and the BUND reached an out-of-court settlement. Schleswig-Holstein agreed to provide 14 million euros to establish a foundation dedicated to bat conservation, clearing the way for construction to resume.

The project carries a price tag of 465 million euros for the southern bypass alone. According to earlier statements by the planning company Deges, roughly one-tenth of those costs are linked to nature conservation measures.

Beyond local traffic relief, the A20 section is a small but strategic piece of a larger northern German transport puzzle. It is part of a long-term plan to create a new Elbe crossing west of Hamburg, easing pressure on existing routes.

A Wider Regional Impact

Currently, motorists crossing the Elbe rely on the A1 Elbe bridges, the A7 Elbe Tunnel, or the Glückstadt-Wischhafen ferry. All three routes are prone to frequent congestion.

Planning and approval processes for subsequent A20 sections, including a proposed Elbe tunnel near Glückstadt and the route through Lower Saxony, are at varying stages of progress.

For residents of Bad Segeberg, the groundbreaking represents the end of decades of uncertainty and the promise of quieter, safer streets. The project is expected to significantly cut through-traffic and improve air quality in the town center.