Comfort in the tunnel

Åse Dragland
Ill: PIR II Arkitektkontor

Green plants cover the rock walls. The emergency telephone flashes a red signal of warmth towards you. You have passed the yellow section in the tunnel and you know that only 200 metres remains. Relaxing music plays on the pre-set channel on the car radio.

To supress the feeling of unpleasantness in tunnels, using the nature as decoration is one tool.

This is not the scenario that we usually connect with tunnels, which instead often promotes a feeling of tension, fear and unpleasantness.

For older people and many women, driving through tunnels is an extremely unpleasant experience. They may begin to think that the tunnel is closing in around them, and feel totally exhausted when they finally reach the end of the tunnel.

For some people driving in tunnels becomes so scary that they develop a phobia and only specialised counselling prevents them from becoming paralysed with fright.

The Sogn and Fjordane county office of 'Statens Vegvesen', the national highway authority, has taken the fear of tunnels seriously. It will lead the way with 'psychologically correct tunnels' when the 25 kilometre long Lærdal Tunnel opens in 2001. Researchers at SINTEF Civil and Environmental Engineering have been given the task of evaluating efforts to suppress the feeling of unpleasantness.

Last August, the institute invited leading drama advisers, architects and theatre lightning technicians to a seminar in Trondheim to suggest solutions for increasing the comfort in tunnels. The idea of widening tunnels was high on the list. Modelling tunnels in a shape of a trumpet that would increase the width at the entrance, exit and other strategic points within the tunnel, would create a useful tool for breaking up longer tunnels. The Lærdal Tunnel, for instance, could be divided into four sections, each six kilometres in length. In addition to being an ''architectural breathing space", it would provide police with possibilities for speed control and video surveillance. Providing they are located on straight stretches with good visibility, the spaces could also serve as turning bays.

Light, space and air are basic necessities. ''If you drive in a tunnel with poor ventilation, it reduces your feeling of safety and you could put all the best art in the world on the tunnel walls, but it wouldn't make any difference'', says traffic researcher Gunnar D. Jenssen of SINTEF Civil and Environmental Engineering.

Good lightning is seen by the experts as an extremely important tool. For example, creating illusionary room effects and perceptual illusions, such as illuminated lines of columns, to make the tunnel feel larger. According to Jensen, ''The lighter and more spacious a tunnel is, the safer the driver feels.''

Tools which can create a sense of safety, are second highest on the list of tunnel 'musts', followed by a consideration of cognitive factors such as: ''Where am I?" and ''How much further do I have to go?" Aesthetics, neatness and artistic decoration were lowest on the list of factors. One suggestion given consideration was putting plants into the tunnel. ''The logic is if they are able to live in a tunnel, then I must be able to as well."

Colour

Little if anything has been done in Norway concerning artistic decorations in tunnels. There has also never been an investigation into the possible effects of such designs. In Akershus county, in southern Norway, figures with associations to the people who have worked on the tunnel have been painted on the tunnel walls, but the reactions to this have been mixed.

''Using the nature as decoration on tunnel walls is one tool. Colour coding in the tunnel is another," says Jenssen. ''Psychologists can advise which colours are best and in which order they should be used. Green, for example, is a colour that has agreeable and pleasant effects on people, creating a feeling of safety and showing that everything is all right. Experiments have been carried out at the Gudvangen Tunnel using green lights near the tunnel entrance. The results suggest that this signal tended to increase the feeling of safety for drivers."

Jenssen sees the possibility using different colour codes in different parts of the tunnel to help motorists to determine where they are in the tunnel and the number of kilometres remaining before they are once again back in the open air.

Statements like ''we are now in the yellow section" could be useful information too when it is necessary to make emergency calls from inside the tunnel.

Testing in progress

A series of proposals will be tested in an advanced driving simulator in Tromsø, Norway. Graphic representations of the basic model of the Lærdal Tunnel and the prospective road system have already been made. The most current proposals are reconstructed with computer technology and "tested" using the simulator.

By pressing keys on the computer keyboard, researchers can enter different variables to see what the proposed effect actually looks like. For example, light in the tunnel can be altered by the push of a single key. Computer images will be tested on road users to determine which gives the best impact. And who knows: Maybe in a few years time, we will look forward to entering a tunnel!

Gemini fakta

The tunnel between Aurland and Lærdal is scheduled to open in 2001 on the main road between Bergen and Oslo. At 24.5 kilometres long, it will become the world's longest tunnel. The tunnel currently holding the distinction is the St. Gotthard Tunnel in Switzerland, which is "only" 16,9 kilometres. Norway's longest existing tunnel is Gudvangen Tunnel, 11.4 kilometres long.
The Lærdal Tunnel will enable motorists to avoid both landslides and weather-enforced road closures in winter. Since 1940, there have been only eight major accidents in tunnels around the world.