Construction of the Riederwald Tunnel - Last Trees Felled - Hesse's €1.5B Riederwald Tunnel breaks ground after decades of delays

Work has begun on the Riederwald Tunnel, the largest urban infrastructure project in Hesse. The €1.5 billion scheme will finally close a long-standing gap between the A66 and A661 motorways. Planning for the tunnel stretches back over 30 years, with formal approvals first sought in 1989.

The project took a major step forward in February when the Kassel Administrative Court dismissed an emergency injunction aimed at stopping construction. Judges ruled that the tunnel served a clear public interest by completing a missing link in the road network. They also found that measures to protect the endangered Heldbock beetle—such as relocating breeding trees—were adequate.

Clearing of the last trees in Fechenheim Forest started smoothly, with police officers on hand to assist. Authorities reported no protests or disruptions, as no activists were present at the site. The peaceful operation marks the beginning of a lengthy construction phase.

Main works are set to commence at the end of January 2026, with the entire project expected to take around seven years. The first section, including the west portal, should be finished by late 2028. If all goes to plan, the tunnel will open in 2033.

The Riederwald Tunnel will become a key part of Hesse's transport network once completed. With no other projects of this scale currently underway in the region, its progress will be closely watched. The €1.5 billion investment aims to improve connectivity and reduce congestion on existing routes.