12/12/2025
Norway is building the world’s longest and deepest undersea road tunnel to speed up travel between major cities and help create a ferry-free highway along the country’s west coast.
The 27-kilometer (17-mile) tunnel, called Rogfast, will reach a depth of 392 meters (1,286 feet) below sea level. Construction began in 2018, paused in 2019 due to rising costs, and restarted in 2021. It is expected to open in 2033, with a total cost of about 25 billion Norwegian kroner ($2.4 billion).
Rogfast will provide a faster and more reliable route between the Stavanger and Haugesund regions.
By replacing ferry crossings, it will cut travel time between Bergen and Stavanger by about 40 minutes, making commuting much easier.
The tunnel will have two separate tubes, each with two lanes, and a rare feature in the middle: a double roundabout located 260 meters deep that connects to the island of Kvitsøy, Norway’s smallest municipality.
Rogfast is part of a major upgrade to the E39 coastal highway, a 1,100-kilometer (684-mile) route that currently takes 21 hours to drive and includes seven ferries.
Norway aims to remove all ferries by adding tunnels and bridges, reducing total travel time by half. The full project may not be finished until 2050.
To keep the long tunnel safe, it will use a combination of jet-fan ventilation and a ventilation shaft up to Kvitsøy for clean air.
Cameras, radar, and real-time alerts will monitor traffic and detect incidents like breakdowns or congestion.
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