The primary aim of environmental protection is to reduce the impact on air, water and ground to a long-term acceptable level.
The benefits of the construction of a tunnel should consider the greenhouse gas benefits arising from reduction in travel time and vehicle operating costs.
The preservation of the species living around the tunnel may require the set-up of special measures. These measures may be aimed at restoring passageways for certain species or preserving reproduction areas. In some cases, the position of certain technical facilities may be modified (ventilation units, extraction shafts, etc.).
In order to avoid the exceptional presence of these species on the roadway or in the tunnel (which can present significant risks for drivers and for the species in question) specific measures like fencing or enclosures may be necessary.
The use of natural resources should be carefully examined in the design phase, if possible by favouring materials which have the lowest carbon footprint, or by recycling materials already used elsewhere. Also, to minimize the use of energy resources, the design should take into account the energy consumption during both the construction phase (adapt the design to less energy-intensive construction methods) and the operational phase of the tunnel.
With regard to the three components of the environmental pillar (conservation of species, resources and energy), the construction phase has considerable impacts. A tunnel should be built in such a way that the impact on the environment is as low as reasonably practicable. Selected suppliers must:
All the actions planned for the conservation of animal species present in the vicinity of the works or in the vicinity of the finished tunnel must be undertaken in strict compliance with the environmental specifications outlined during the study phase.