A448 Witten-Annen exit shut for months due to unstable mine tunnels below

Ancient Mining Tunnel Beneath the A448 Near Witten-Annen Must Be Filled to Prevent Road Collapse

The Witten-Annen exit on the A448 has been closed since Saturday—and will remain shut for at least three months. The process of filling the abandoned mine tunnels is complex and requires heavy machinery.

35-Meter-Deep Holes Drilled to Fill the Tunnels

First, massive drilling rigs bore holes roughly 35 meters deep, though only a few centimeters wide. Through these, about one container's worth of cement mixture is pumped underground each day.

The work is taking so long partly because the tunnels are difficult to locate. As crews search, they frequently encounter additional shafts that were never recorded on old mining maps.

Illegal Coal Mining Common in the Southern Ruhr Region

The southern Ruhr area is riddled with unmapped tunnels, where coal seams once lay close to the surface—and were often mined illegally. In 2019, an undiscovered tunnel caused over a year of traffic restrictions on the A43 near Sprockhövel.

With the current project, Autobahn GmbH is continuing the stabilization work it began years ago between the Dortmund/Witten interchange and Witten-Annen.