Brenner Base Tunnel

When it opens, the Brenner Base Tunnel will be the longest rail tunnel on earth. The 64-kilometer Alpine crossing runs flat and deep under the Brenner Pass, connecting Innsbruck in Austria with Fortezza in Italy and replacing a steep mountain rail route that has throttled freight between northern and southern Europe for more than a century. Counting the existing Innsbruck bypass it links to, the continuous tunnel system overtakes Switzerland’s Gotthard Base Tunnel as the world’s longest.

Project Scope

The design is three tubes, not one: two single-track main running tunnels plus a central exploratory and service tunnel running below and between them. That exploratory tunnel does double duty, mapping rock conditions ahead of the main bores and later draining water and housing maintenance access. Excavation has been the long grind. Of about 230 kilometers of tunnels in the full system, crews have driven roughly 204 kilometers, including 100 kilometers of the main running tubes. A cross-border breakthrough on the exploratory tunnel landed in September 2025, and the main-tube breakthroughs at the national border are expected around mid-2026. The binational company BBT SE owns and builds it, with the European Union co-funding the link as a spine of the Scandinavian-Mediterranean corridor at an estimated cost near 8.8 billion euros.

Why It Matters

The point is freight, and emissions. Today trucks haul most goods over the Brenner, one of the busiest and most contested freight corridors in the Alps. A flat, fast base tunnel lets long, heavy trains take that load, cutting transit time and shifting tonnage off the motorway and onto rail. For the Alpine valleys that have absorbed decades of truck traffic, the air-quality math is as compelling as the logistics.

It’s also the European counterpart to the deep-bore approach behind other continental rail megaprojects: bore deep, go straight, and let geography stop being the bottleneck. Opening is now targeted for around 2032, a reminder that the longest tunnels take the longest to finish.

Project Team & Details