The longest road tunnel in the world has an anti-claustrophobia system

Driving through them is a luxury. An experience. They are the longest tunnels in the world: miles and miles of roads that stretch out under geographical features such as mountains or oceans, challenging nature in the name of connectivity. One of them is the Yamate Tunnel, in Japan, 98 feet below the surface and 11.3 miles long. Another is the Zhongnanshan Tunnel (11.21 miles), in China, which allows users to travel in 40 minutes what used to take approximately three hours. Still, there is another, even longer one. Which is it?

One of the main features of Norway is its geography: a combination of mountains and lakes, along with its cold climate, complicates the connections. That is where engineering comes in.

The longest tunnel in the world

The longest tunnel in the world, 15.23 miles in length, can be found there. Located in the southwest of the country, it connects the municipalities of Lærdal and Aurland with a slope of 2.5%: from 16.5 feet above sea level to 870. It took five years to build, from 1995 to 2000, when it was finally opened to traffic. Technically, there is another, even longer tunnel: Saint Gotthard, in Switzerland. However, it is a railway tunnel, not intended for cars.

Due to its impressive length, it has become a tourist attraction. Visitors have enough space to park and take photographs. Its popularity is such that even weddings have been held there.

A claustrophobia-free tunnel

It has blue and yellow lighting in order to simulate a sort of dawn, keep drivers alert, make the journey more pleasant and avoid possible claustrophobia attacks. With the same purpose, it has illuminated rock caves every 3.7 miles, which change the atmosphere and reduce monotony. All these ideas were provided by a team of psychologists that developed the appropriate techniques to help relieve the feeling of confinement.

Due to its length, this work of engineering has other special features, such as rumble strips that warn drowsy drivers when their vehicle drifts out of its lane. In addition, at certain points there are signs indicating how long is left to go. It also has emergency telephones connected to the police, firefighters and medical assistance services, and of course, speed radars to prevent accidents.

A true engineering masterpiece

To build it, it was necessary to remove 3.3 million cubic yards of rock, an operation that cost approximately $100 million. Given the long journey, before exiting the tunnel the eyes need to readjust to the sunlight; this is why, as the end approaches, a series of bright lights help the drivers get used to the changing light conditions. There is also an air treatment plant that works with some large fans installed along the road, with the aim to improve the air quality.

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