World's Deepest Underwater Tunnel to Have Cars Drive 16 Miles Under the Sea

Newsweek

29-06-2025

Based on facts, either observed and verified firsthand by the reporter, or reported and verified from knowledgeable sources.
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Norway is building what is to become the longest and deepest road tunnel under the sea.
The Rogfast project, measuring 26.7 kilometers (about 16.5 miles) and descending to 392 meters (nearly 1,300 feet) below sea level, is scheduled to open in 2033.
The tunnel is a part of Norway's effort to connect a highway along the country's west coast. The current route—the E39—includes multiple ferry crossings and takes over 21 hours to drive. Once open, Rogfast will cut that journey by nearly half, easing travel between Stavanger and Bergen.
Newsweek contacted the Norwegian Public Roads Administration for more information on the project's progress via email.
Why It Matters
The tunnel is one of several infrastructure works being built to remove ferry crossings on the E39 highway. The corridor runs from Kristiansand in the south to Trondheim in the north. Rogfast alone will link the municipalities of Randaberg and Bokn by road, replacing the need for ferry transport in this section.
Images of construction work for the Rogfast tunnel in Norway.
Images of construction work for the Rogfast tunnel in Norway.
Skansa
The region surrounding the route is home to key parts of Norway's economy, including the oil and seafood industries. Officials estimate Rogfast will carry 6,000 vehicles per day once it opens. Tolls are expected to be around £30, about $38, per trip, according to Euronews.
What to Know
Construction began in 2018 and is organized into three tunneling sections.
Contractors Implenia/Stangeland Maskin are handling two of the three sections, while Skanska is building the third. Together, the segments include more than 37 kilometers (nearly 23 miles) of tunnel boring, including a central interchange under the sea near the island of Kvitsøy.
A rendering of the Rogfast tunnel, which will be the deepest structure of its kind in the world once completed.
A rendering of the Rogfast tunnel, which will be the deepest structure of its kind in the world once completed.
Norwegian Public Roads Administration
Crews are using drill-and-blast methods throughout, and will remove around 8 million cubic meters (over 280 million cubic feet) of rock. The twin tunnels, spaced nearly 50 feet apart, will each carry two lanes of traffic.
Driving the full length will take about 35 minutes at 50 kilometers per hour (just over 30 mph). Ventilation shafts will extend more than 200 meters above the tunnels, and a road junction will be built beneath the seabed near Kvitsøy.
The cost has been estimated between £1.45 billion and £1.74 billion (nearly $2 billion and $2.4 billion). The Norwegian government aims to provide about 40 percent of the funding. The rest will come from toll revenue once the tunnel opens.
Images of construction work for the Rogfast tunnel in Norway.
Images of construction work for the Rogfast tunnel in Norway.
Implenia
What People Are Saying
Oddvar Kaarmo, project manager of the Rogfast project at the Norwegian Public Roads Administration, told Euronews: "Stavanger is the fourth-largest city in Norway, and Bergen is the second largest, so we hope that it's possible that this project will be able to reduce traveling time for workers as well when they are traveling to either Stavanger or Bergen on a daily basis."
What's Next
Tunneling is expected to finish by 2030. Installation of lighting, drainage, ventilation, and road surfacing will follow. Full operations are scheduled to begin in 2033.