Germany clears a key missing link for Stuttgart 21
Germany has secured federal funding for the Pfaffensteig Tunnel, a long-planned link intended to enable the remaining capacity and network effects around the Stuttgart rail hub.
The tunnel is one of the last major components still required to realise the full capacity effects of the Stuttgart 21 programme.
Its inclusion in a federal rail investment package shifts attention from financing to approvals, construction sequencing and integration with the wider Stuttgart 21 programme.
From “funding secured” to delivery constraints
The federal financing commitment, announced on 29 January, removes uncertainty over whether the Pfaffensteig Tunnel would be funded.
With funding now secured, attention shifts to delivery — including approvals, construction sequencing and how the tunnel is integrated with the wider Stuttgart 21 programme.
In November 2025, Deutsche Bahn said it could no longer meet the December 2026 commissioning target for Stuttgart 21 and did not name a revised date. The City of Stuttgart said it had been informed that the project would miss the deadline.
Stuttgart 21 replaces the city’s above-ground terminus with an underground through-station linked to new tunnels and upgraded approach tracks. The project is intended to increase capacity for long-distance and regional traffic and to form a key node in the future Deutschlandtakt.
What Stuttgart 21 is — and what still blocks the full effects
Stuttgart 21 is one of Germany’s most complex infrastructure projects and has seen successive delays alongside rising costs. Budget estimates have grown from around EUR 4.5bn to above EUR 10bn as engineering challenges and ground conditions became clearer.
In the government’s description, Pfaffensteig is intended to enable the remaining capacity and network effects around the Stuttgart hub once the final set of connections is in place.
What to watch: approvals, sequencing, and the revised timetable
With funding now secured, the constraint shifts to delivery: approvals, construction sequencing, and integration with the wider Stuttgart 21 works around the node.
A revised overall schedule for completing Stuttgart 21 and the related network works remains a key dependency as Pfaffensteig is integrated into the existing system.
Stuttgart 21 is a hub rebuild where the expected capacity and network effects depend on connecting projects being delivered in the right sequence.
Securing funding for Pfaffensteig removes a key “if” — but shifts attention to approvals, sequencing and how the tunnel integrates with the wider Stuttgart node.