Infrastructure Past, Present, and Future Casebook/Norway Floating Highway

thumb|Rogfast Underwater Floating Tunnel Introduction The Norway Floating Tunnel is a proposed infrastructure project designed to provide a continuous road connection across Norway’s fjords as part of the E39 Coastal Highway Route. This specific project aims to eliminate the need for multiple ferries along the western coast of Norway by introducing a Submerged Floating Tunnel (SFT), a type of underwater structure that would be suspended below the water surface using floating pontoons and/or anchored cables. [1] This concept was developed in response to the region’s challenging geography, where traditional bridges and tunnels are difficult to build due to deep waters and wide fjords in the area. The floating tunnel would allow for vehicles to travel beneath the surface of the water while remaining unaffected by weather conditions and maritime traffic above. If this project is built, it would be the first structure of its kind in the world and a major milestone in transportation engineering globally. This project has been studied as part of Norway’s broader efforts to improve connectivity, reduce travel times, and develop innovative engineering solutions suited to its natural landscape. Background thumb|Map illustrating where the Rogfast Tunnel would be laid. Norway has rugged terrain and deep fjords that make development in transportation a major engineering challenge. Traditional bridges and tunnels are often viewed as impractical due to the extreme water depths and long spans separating communities along the western coast. The Norwegian Public Roads Administration (Statens vegvesen) launched the E39 Coastal Highway Route project, which seeks to replace ferry connections along the 1,100 kilometer route between Kristiansand and Trondheim with various continuous road links. The project’s goal is to overall reduce travel time from about 21 hours to 11 hours by 2050 with finished development. [2] Many infrastructure solutions considered is the floating tunnel, or submerged floating tunnel which is a world-first concept designed to cross Norway’s deepest fjords, such as the Sognefjord, which is about 3700 meters wide and 1,300 meters deep. The concept plans to have two concrete tubes submerged roughly 20 to 30 meters below the water surface, supported by pontoons to the seabed with cables. Vehicles would travel through these tubes similarly to a conventional tunnel, while the structure floats smoothly underwater while being protected from weather and ship traffic above. thumb|One of the tunnel entrances of the E39 highway. Once complete, all of these roadways will be interlinked. If constructed, Norway’s floating tunnel would be the first of its kind globally, combining elements of bridge, tunnel, and marine engineering. Research and feasibility studies began in the early 2010s through collaborations between Statens Vegvesen, SINTEF, NTNU (Norwegian University of Science and Technology), and DNV. Many of these studies have focused on hydrodynamic stability, material durability, safety under extreme weather conditions, and long-term maintenance. Testing continues as part of Norway’s long term innovation in fjord-crossing infrastructure. According to experts, floating submerged tunnels are not only the future of transportation engineering, but may be the only promising way to cross great expanses. The environmental impact of SFTs is also beneficial as complex air treatment processes are required to mitigate exhaust from underground vehicles, particulate matter would otherwise be released untreated and are processed and scrubbed before being released into the atmosphere. The sporadic ferry crossings currently used in Norway would be obsolete and the associated carbon emissions consequently reduced. The travel time between northern and southern Norway would be significantly reduced to just under 10 hours, lowering carbon emissions by 50% and providing the economic benefits of saved time. The Norwegian government remains optimistic for the promising environmental impact and traffic alleviation. [3] Timeline E39 Highway: Broke ground 2015 thumb|Entrance to the underwater Solbakktunnelen. The proposed entrance to the Rogfast Tunnel will be similar in size and dimension as this one shown. Scheduled to open in Summer 2050. Rogaland Fixed Link Underwater Tunnel: Planned in 2017, planned to finish 2026-26 Construction began in 2018 Project construction and demolition stopped on October 2019 due to budgetary oversights. The Norwegian government pulled contracts and future contracts were canceled. Norwegian officials requested a full review over the budget and plan over the Rogfast in December 2019(https://www.nrk.no/rogaland/vegdirektoratet-set-i-gang-full-gjennomgang-av-rogfast-1.14825643). The Norwegian Public Roads Administration brought a revised update of the budget on April 2020, amounting to an increase of 8 billion NOK from an original 16.8 billion NOK estimated in 2017(https://www.tu.no/artikler/vegvesenet-om-rogfast-4-milliarder-kan-kuttes/491039). The first main contract, valued at 5 billion NOK, was awarded to Skanska in December 2022 for the construction of the northern entrance to the Rogfast bridge (https://group.skanska.com/media/press-releases-articles/269196/Skanska-builds-subsea-tunnel-in-Rogaland-County%2C-Norway%2C-for-NOK-5-billion%2C-about-SEK-5.2-billion). The contract for the construction of the southern entrance valued at 4 billion NOK was awarded on January 2023 to Implenia Norge (https://implenia.com/en/media/news-article/implenia-gewinnt-grosses-komplexes-tunnelprojekt-in-norwegen-e02-kvitsoey-e39-rogfast/). The final contract, aimed at constructing the middle portion of the tunnel was awarded on June 2024 to two companies; Implenia and Stangeland. The contract for the construction is valued at 6.2 billion NOK (https://www.geoengineer.org/news/implenia-led-joint-venture-secures-second-contract-for-major-norwegian-sub-sea-road-tunnel). Demolition contractors Hæhre and Risa completed the blasting phase of the Kvitsøy tunnel in November 2023, responsible for around 800 controlled blasts the distance of 3.5 kilometers. Hæhre and Risa started the foundations of a waters and sewage system, and are projected to finishing the contract by the first half of 2024 (https://www.facebook.com/e39rogfast/posts/pfbid0CTnw9waUAp2eqGWkXhVKjTCWzNNRi2KCJNaopWKm4NYAAzkikpof45sY6gH2Gcdjl). The Rogfast tunneling went past the depth of 296 meters on August 2025, beating the world record holder, the Ryfast tunnel from a depth of 292 meters in the water (https://www.facebook.com/e39rogfast/posts/pfbid06XR3TyYPubM8eLJrB1PwUaKgUpKWjWCembHDkLTcLkV6F1eafS2hZcgcpXMuGgo8l). Policy Issues This new project has pushed the boundaries of modern transportation. The National Transport Plan E39 (NTP E39) has the loft political aim of shortening the commute from southern Norway’s staple harbor town of Kristianstad to the northern town of Trondheim. This distance stretches over 1,000 kilometers and requires nearly 20 hours to complete by car. The cumbersome archipelago of Norway’s western coast, which is made up of thousands of fjords with varying sizes, renders the journey impossible without the use of several ferries to complete the journey. Another issue would be the concern of the Norwegian people and government for the environment placing constraints on possible resolutions to this transportation conundrum. More specifically a challenge for engineers on the NTP E39 plan is how to pass the Sognefjord with a 3,700 meter stretch at its narrowest point between Lavik and Oppedal. Sognefjord’s maximum depth of 1,300 meters (about one mile), makes standard underwater tunneling impractical and detrimental to the sensitive coastal ecosystem. [4] Depending on the buoyancy design and environmental factors impacting the submerged floating tunnel, one of four engineering methods may be required to anchor the SCT in place such as column or tension leg supports. Pontoon supports may be utilized as well to support a SFT that would sink. Submerged floating tunnels are subject to external forces such as water current, earthquakes, sub-zero temperatures, and watercraft movement; more support is necessary to maintain a constant, stable environment for the tunnel. As this maintains a sense of safety and structural integrity of the tunnel. [6] Safety is the primary concern for all engineering studies concerning the feasibility of submerged floating tunnels. The biggest concern is the potential breach of water into the body of the tunnel. To combat this, safety routes (similar to modern tunnels) are integrated into the blueprints, ensuring a reliable exit in the event of an emergency. The other concern is seismic activity. Natural disasters are well planned, and the impact of accidents (including boat crashes) have been analyzed and considered in the Sognefjord tunnel, which would withstand the loss of several surface pontoons without sustaining damage to the tunnel below. The safety and experience for potential travellers, is by all calculations, projected and planned to be equivalent to standard tunnel travel. The Norwegian government remains optimistic for the promising environmental impact and traffic alleviation. The science and public demand make an underwater submerged tunnel an anticipated and a necessary advance in transportation technology. Conclusions 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." [7] The proposed Norway Floating Tunnel represents one of the most ambitious and innovative infrastructure projects in present day engineering. Developed as part of the E39 Coastal Highway Route, the project aims to overcome the geographical challenges of Norway’s fjord landscapes by implementing a technology never before used at full scale. While the concept of a submerged floating tunnel (SFT) has been explored theoretically for decades, Norway’s initiative of this project marks the first real attempt to test its technical, environmental, and economic feasibility in real world conditions. If this gets cleared and completed, the floating tunnel could dramatically improve connectivity between southern and central Norway, reduce travel times, improve stimulations between regional development, and setting a global precedent for deep-water crossings. However, the project continues to face significant challenges such as high construction costs, complex safety requirements, and environmental uncertainties. Ongoing research by Statens vegvesen, SINTEF, NTNU, and DNV seeks to address these concerns through simulations, scale testing, and detailed feasibility analyses. Overall, the Norway Floating Tunnel illustrates the country’s commitment to sustainable innovation and forward-looking infrastructure design. Whether the tunnel is ultimately constructed or not, the research and engineering behind it are likely to influence future subsea transport projects worldwide, offering new solutions to the growing for safe, efficient, and environmentally responsible connectivity in difficult terrain. References List [1] Lo, A. (2019, January 29). Can Norway win the global race to build a ‘floating tunnel’? CNN. https://www.cnn.com/style/article/norway-underwater-floating-tunnel-intl [2] Norway pioneers first floating underwater tunnels. (2016, August 11). Born to Engineer. https://www.borntoengineer.com/norway-pioneers-first-floating-underwater-tunnels [3] Norway plans to build £1.6bn underwater ‘megatunnel’ to halve 21 hour drive time. (2024, December 16). The Independent. https://www.the-independent.com/travel/news-and-advice/norway-underwater-megatunnel-e39-coastal-highway-b2665047.html [4] Submerged floating tube bridges—Long span bridges—Research—Structural dynamics—Department of structural engineering—Ntnu. (n.d.). Retrieved October 14, 2025, from https://www.ntnu.edu/kt/research/dynamics/research/long-span/submerged-floating-tube [5] World’s deepest underwater tunnel to have cars drive 16 miles under the sea. (2025, June 29). Newsweek. https://www.newsweek.com/worlds-longest-underwater-tunnel-car-drive-norway-2090927 [6] World’s first “floating tunnel” proposed in Norway. (2019, February 15). NBC News. https://www.nbcnews.com/mach/science/world-s-first-floating-tunnel-proposed-norway-ncna971581 [7] (N.d.). Retrieved October 14, 2025, from https://www.euronews.com/next/2025/04/09/norway-is-building-the-worlds-longest-and-deepest-subsea-road-beneath-its-fjords