Construction of long tunnels in Norway

Tunnels are important parts of the communication system in the mountainous country of Norway. The paper gives short descriptions of selected long traffic tunnels, including the 24.5 km long Lærdal tunnel, the longest road in the world. During later years emphasis has been put on the principle of sectional completion during construction. Pros and cons of this principle is demonstrated and discussed. A comparison of costs between long traffic tunnels in Norway and Switzerland is also presented. This shows that cost-wise construction of long tunnels in Norway is extremely competitive, Norwegian long traffic tunnels are in the order of 1/10 of the cost per kilometre in Switzerland.