The impact of lighting on drivers well-being and safety in very long underground roads: New challenges for new infrastructures

Lighting installations in underground roads and tunnels have been focused on the classical problems of road tunnels, that is, provide high luminance levels ensuring a correct visual adaptation of drivers during daytime and, hence, a safe driving and underground transport. The achievement of such levels with a minimum consumption in energy and raw materials, has become an active field of research during the last years. However, this line of work is mainly focused on tunnels, that rarely exceed two kilometers long. The increasing number of very long underground roads (VLUR) like those under rivers and seas, has enhanced the importance of some factors directly related to well-being and highly influenced by the lighting and visual conditions. These factors, that go from higher stress and anxiety to more distraction or fear, seriously impair safety and constitute a new challenge for designers of lighting installations. In this work, some of these problems and their potential solutions will be analyzed and the conclusions presented.