Laerdal, the longest road tunnel in the world

The Laerdal Tunnel is a road tunnel in Norway that is considered to be the longest road tunnel in the world. It is located in the municipality of Lærdal, about 90 kilometers (56 miles) northwest of the city of Bergen. The tunnel is 24.5 kilometers (15.2 miles) long and runs through the mountains of Western Norway.

Country	Norway
Length	24,5 kilómetros (15.2 miles)
Built in	From 1995 to 2000
Cost	€115 million
Inauguration	November 27, 2000
Maximum height of the drilled mountain	1.809 meters
Spilled cement	35.000 m2
Perforated surface	2.5 million cubic meters
Traffic	1,000 vehicles daily

The tunnel was officially opened in 2000 and has significantly reduced travel time and improved safety for motorists. It is equipped with lighting, ventilation, and emergency telephones. The tunnel is also equipped with an automated speed control system and vehicles are monitored by CCTV. Although there are longer railway tunnels, such as Seikan in Japan or the one linking the United Kingdom and France, Laerdal could be the longest road tunnel in the world. It has become a source of pride for locals and a typical tourist destination in Norway for foreigners.

The Construction of the Laerdal Tunnel

The Laerdal tunnel was built to avoid crossing a mountainous part of the country made up of narrow, outdated and unsafe roads. As a result, in 1975, the Norwegian Parliament decided that the road linking Oslo and Bergen should have the current route. In 1992, the Parliament confirmed that decision and made the additional decision that the road should pass through a tunnel between Laerdal and Aurlandsvangen. Thus, the Laerdal tunnel was built between 1995 and 2000, and cost approximately 115 million Euros. For the construction of the tunnel, a total of 2.5 million cubic meters of rock was extracted from the mountain and used to build part of the new road between Flåm and Aurlandsvangen, and to construct a pedestrian and bicycle path along the Aurlandsvangen fjord.

Driving the Laerdal Tunnel

To break up the monotony of driving during the 20-minute journey, the tunnel has been divided into four sections by creating three large caverns, one at each end and one in the center, illuminating them in such a way as to make it appear as if you are driving in daylight.

Safety in the Laerdal Tunnel

At 24.5 kilometers, the Lærdal Tunnel is not only the longest in the world, but it is also one of the safest. In addition to all of the above, a number of safety measures were taken into account during construction:

• Telephones every 250 meters
• Fire extinguishers every 125 meters, more than any normal tunnel.
• When an emergency telephone is used, STOP signs and “Turn around and leave the tunnel” signs are illuminated.
• 15 areas adapted to allow trucks and buses to turn and go in the opposite direction
• 2 safety monitoring centers installed in Bergen and Laerdal.
• Entering and leaving vehicle counter.

The Strategic Link Between Norway’s Two Major Cities

The tunnel is a key strategic point for connecting Norway’s two most populous cities, Bergen in the west and Oslo in the east, by road. It is especially important for winter traffic, when the mountain passes linking the two cities are closed due to snow. The mountains above the tunnel reach elevations of up to 1,800 meters, and the road linking Aurlandsvangen and Laerdal, called Snøvegen or Snow Road, is open only during the summer months, making it impossible to cover the route in winter. A 2.1 kilometer access tunnel was constructed from a lateral valley that allowed operators to drill from four different locations, significantly shortening construction time. The tunnel is of great importance for the municipality of Aurlandsvangen, as it means that it is no longer isolated and connects it with other surrounding municipalities such as Laerdal, Ardal, Sogndal, Luster, Leikanger and Balestrand.

Tourist attraction

The Lærdal Tunnel is a popular tourist attraction, and many visitors take the opportunity to drive through the tunnel to experience the unique and impressive engineering feat. The tunnel is also popular with hikers and cyclists, who can use the tunnel’s pedestrian and bike paths to cross the mountains. Overall, the Lærdal Tunnel is an impressive and important transportation route that has greatly improved travel and connectivity in Norway.

Air cleaning

Air cleaning in the tunnel is achieved in two ways: ventilation and purification. For ventilation, there are two large fans that suck in the air at each entrance, expelling the contaminated air through the side ventilation tunnel named above. For purification, an air treatment plant was built in the tunnel (it is the first tunnel in the world with this equipment). This plant removes dust and nitrogen dioxide from the air flowing through the tunnel.

Panoramic view of the Laerdal Tunnel, photo by Kenneth Rivenes

References Wikipedia and Bergen Guide

Versión en Español: Laerdal, el túnel más largo del mundo