The Laerdal Tunnel in western Norway holds the title of the world's longest road tunnel, stretching 24.5 kilometres (15 miles) beneath a mountain range. Constructed at a cost of £75 million, it connects the towns of Aurland and Laerdal in the heart of Sogn, providing a ferry-free link between Oslo and Bergen.
Construction and Scale
Building began in 1995 and was completed in 2000. During construction, approximately 2.5 million cubic metres of rock were excavated. The tunnel is divided into four sections separated by three large caves, which serve as turning points during the roughly 20-minute drive.
Innovative Design to Combat Fatigue
The tunnel is renowned for its design that actively combats driver fatigue and claustrophobia. The main sections are illuminated with white lights, while each cave features blue and yellow lighting around the edges to mimic a sunrise. These caves provide drivers with a brief visual respite.
A rumble strip in each lane helps prevent drivers from losing concentration. At each kilometre mark, a sign indicates the distance covered and the remaining distance ahead.
Air Treatment Plant
The Laerdal Tunnel is the first in the world to be fitted with an air treatment plant. Housed in a cavern 100 metres wide, the facility extracts dust and nitrogen dioxide from the tunnel's air supply, ensuring better air quality for drivers.
