This European country is often defined by mountains, passes, lakes, and railways. What lies beneath the surface, however, isfar less visible. Over the past several decades, this country has invested heavily in tunnels designed to transport people, goods, water and energy across challenging terrain. This development did not follow a single-master plan or belong to one specific era. Instead, it evolved step by step, shaped by geography, post-war reconstruction, and the growing demand for efficient transport networks.
Today, Switzerland has thousands of tunnels stretching acrossthousands of kilometers. Some are short and serve local needs, while others run for dozens of kilometers through solid rock.Together, they form a system that supports everyday life while remaining largely hidden from view.
One of the World’s Largest Tunnel Networks
The landscape offers few alternatives. Much of the country is mountainous, with sudden changes in altitude over short distances. The construction of railroads and railways on the surface is often slow, expensive and disruptive. Tunnels provide routes that avoid exposure to harsh weather, steep gradients and unstable slopes. It is also important to take mobility into consideration. Switzerland records a high volume of daily travel, both domestically and across borders. Infrastructure is expected to function reliably and reach even remote regions. As a result, tunneling has become a practical solution rather than an engineering exception.
The Underground Network
According to the Swiss Tunneling Society, Switzerland has built 1,852 tunnels with a combined length of 2,544 kilometers. Theseinclude road tunnels, railway tunnels and older structures associated with water supply and energy systems. From the surface, the scale of this network is difficult to grasp. Measured purely by length, the underground systems rival the network ofmajor cities. In some regions, underground travelling accounts for a significant share of overall movement.
The Role of Underground Motorways
Switzerland’s motorway network is among the densest in the world. Currently, 1,840 kilometers of national motorways are in operation, with nearly 250 tunnels forming a part of that system. Once planned sections are concluded, the total length is expected to reach nearly 1,893 kilometers, including more than 270 tunnels extending for approximately 290 kilometers. Many motorways run through tunnels to limit noise, reduce land use or pass beneath urban areas. At least three quarters of network consists of four-lane divided roads, many of which carry international traffic.
Tunnel Expansion Since the 1950s
According to Swiss authorities, large-scale expansion began after the World War II. From the 1950s onward, Switzerland started constructing major drainage tunnels for hydropower plants. Road tunnel construction took place in 1980s, whilerailway tunnels became a primary focus after 2000. Today more than a tenth of both the motorway and railway network run underground, a proportion considered a global record. At least 50 railway tunnels and 55 road tunnels exceed two kilometers in length, and their total length continues to grow.
Gotthard Base Tunnel – The World’s Longest
The Gotthard Base tunnel is often addressed as a symbol of this approach. Opened in June, 2016, it stretches for 57 kilometers, making it the longest tunnel in the world. It allows trains to ride across the Alps at low altitude, reducing the travel time and energy consumption. While it stands out as a landmark project, it is part of a bigger picture. Long base tunnels now form the backbone of Swiss railway transport, redirecting traffic from roads to the railways.
Are Tunnels Built Only in the Alps?
A large share of recent activity has taken place outside the high mountain regions. The Central Plateau emerged as a focal point due to congestion and urban expansion. Plans include a 30-kilometer railway tunnel linking Zurich and Rupperswil to ease a major bottleneck. Other developments in the Zurich area include the Brüttener tunnel and a second Zimmerberg Tunnel. Road projects also support the expansion of underground routes, especially in cities such as Basel, Lucerne, Bern, and St. Gallen.
What Lies Beneath Swiss Cities?
Major cities have developed extensive tunnel systems around their railway stations. Zurich opened a new underground station in 2015 in order to manage east-west traffic flows. Further expansions of underground infrastructure are planned in Basel, Bern, Geneva, and Lucerne. These spaces are designed to be functional rather than monumental. Platforms, service corridors, ventilation shafts, and emergency exits form a quiet layer beneath the streets, designed to withstand daily pressure before fading back into routine.
