Austria's most ambitious railway project in a century opened in December 2025 — and cut a 2.5-hour journey to 41 minutes. The story of how patience, tunnelling records, and €6 billion transformed a mountain range.
There is a mountain range in southern Austria called the Koralpe. For most of the twentieth century, it sat between the cities of Graz and Klagenfurt like a wall. Getting from one city to the other — two of Austria's largest — took two and a half hours by train, zigzagging around the mountains on old single-track lines. Driving wasn't much faster. A direct rail link was technically possible, but nobody had attempted it. The mountain was simply too large.
In 1999, Austria decided to go through it.
Twenty-seven years underground
The Koralm Railway — Koralmbahn in German — opened to passengers on 14 December 2025, after 27 years of planning, environmental studies, tunnelling, and construction. It is the first completely new long-distance railway built in Austria in approximately a century. The project cost €6.1 billion. And it delivers exactly the kind of number that makes infrastructure nerds go quiet for a moment: Graz to Klagenfurt, 130 km, in 41 minutes.
That is not a typo. The journey that used to take two hours and thirty-five minutes now takes forty-one. A 78% reduction. At speeds up to 250 km/h on ÖBB's Railjet trains, the Koralpe mountains — which once blocked the route entirely — are now just something you disappear into for a few minutes and come out the other side.
The heart of the project is the Koralm Tunnel: 32.9 km of twin bore running under 1,250 metres of rock at its deepest point. It is Austria's longest railway tunnel and, at the time of completion, the sixth-longest railway tunnel in the world. Building it required three tunnel boring machines, more than 800 workers at peak construction, and a TBM that was driven continuously through hard rock for over 17 km — a world record at the time for hard-rock TBM operation.
The first day
On the morning of December 12, 2025, Austrian President Alexander Van der Bellen and Chancellor Christian Stocker stood simultaneously at Graz Hauptbahnhof and Klagenfurt Hauptbahnhof — connected by live video feed — to inaugurate the line. The inaugural train completed the journey in 39 minutes carrying 800 passengers. By the end of the first day, 10,000 people had ridden 30 trains on the new corridor.
ÖBB now runs 29 direct daily connections between the two cities. Before the line opened, Carinthia (the state Klagenfurt is in) had 8 direct long-distance bus connections to Graz. It now has 29 train services — rail replacing road at a stroke. German ICE 4 trains also use the corridor, running through to Frankfurt. Czech Railways operates ComfortJet services on the southern route. In March 2026, private operator Westbahn launched services from Vienna through to Klagenfurt.
Why this matters beyond Austria
The Koralmbahn is worth knowing about because of what it demonstrates about infrastructure timelines. The project was conceived in the 1990s, built through the 2000s and 2010s, and opened in 2025. The people who approved the first tunnelling contracts are likely retired. The Austrian engineers who designed the TBM cutterheads for Koralpe's geology have seen the project go from drawing to opening over the course of careers.
That is not unusual for major rail infrastructure. It is, however, often forgotten. When a project stalls or costs more than expected mid-build, it is easy to look at the current number and lose sight of the endpoint. The Koralmbahn is a reminder that the endpoint exists — and that it tends to be worth it.
India's own long-in-progress infrastructure projects include the Mumbai–Ahmedabad bullet train corridor, the Delhi–Meerut RRTS (now partially open), and Bengaluru's own Phase 3 Metro (Orange and Grey Lines, Union Cabinet-approved in 2024, construction underway, target 2031). These projects also measure their timelines in years, not months.
In Bengaluru specifically, the metro network has been expanding since Phase 1 opened in 2011. Phase 2A (the Yellow Line) opened in August 2025 after roughly a decade of construction. Phase 3 has just broken ground. The 41-minute Graz–Klagenfurt run, made possible by 27 years of patience and €6 billion of investment, is a reasonable model of what eventually becomes possible when you keep going.
Sources
- Europe's 'number one rail country' celebrates Koralmbahn opening
- Austria marks a 'new railway era' with the opening of the Koralmbahn
- Koralmbahn goes into service
- Koralm Railway — Wikipedia
- Austria celebrates Koralm high-speed line opening after 27 years of construction
- The Koralm Railway — ÖBB-Infrastruktur AG