Following the indications of the snow report, a tunnel was designed that penetrates the slope sufficiently to ensure the continuity of the inclined plane for avalanche sliding, thereby attenuating the dynamic stresses produced on the structure of the tunnel itself during the peak phase. To optimize the cost/benefit ratio, it was chosen to straighten the road axis itself up to the right-hand curve about 300 meters downstream of the avalanche channel constituting the primary reason for the construction of the work in question. This choice has led to the following advantages:
- reduction of the length of the tunnel and therefore of the costs to build it;
- reduction of the excavation to be carried out for the construction, particularly burdensome considering the steep slope of the hillside, with significant advantages both in terms of costs and environmental impact;
- elimination of the right-hand curve downstream of the tunnel, dangerous because it is located at the exit of an underground passage of a road with a steep gradient (13%) and often snow-covered during the period of maximum use;
- increase in safety resulting from the wide visibility in the sections immediately before and after the tunnel, as well as in the journey through the tunnel itself, conceived as perfectly straight along its entire longitudinal axis.
- To increase the protection of the road from avalanches, two earth and rock embankments were chosen to be built on the sides of the last section of the avalanche channel, in order to guide snowflows and potential rocks unambiguously and reliably within the area of the road track protected by the tunnel.
