Laerdal Tunnel

The Laerdal Tunnel, in Norway, is the longest road tunnel in the world, running for roughly twenty-four kilometers beneath mountainous terrain between the towns of Laerdal and Aurland. It was built to provide an all-weather road link on a route previously subject to closure by winter conditions on the mountain roads it replaced, and its design includes several large illuminated caverns spaced along its length, intended to break up the monotony and psychological strain of the long underground drive for motorists. It stands as a major example of Norwegian expertise in tunneling through difficult mountainous terrain.