The safety of the tunnels is the aspect more carefully when planning its construction. What prevails is the safety of the operarios who built it, proximos to the tunnel residents and prospective users. Spain has made very significant advances in this field. The awareness for the safety of personnel during the construction of the tunnels is very large. They have drastically disminuido the accident rate in the construction of tunnels to be below the average construction. On the other hand, the number of dead and injured by road accidents is much smaller than tunnels in stretches open pit. The importance of the construction of tunnels for the structuring of the Spanish territory and the interest of the international community to improve security in the construction of tunnels have contributed to large efforts in the normativo field in the investment. This has been reflejado positively in an increase in the levels of safety in tunnels and, in general, of the underground infrastructures.

The concern about security in the construction of tunnels has caused a greater approximation to the problem which has allowed bring to light flaws or weaknesses encountered in the past even. The fire in the Mont Blanc tunnel, for example, showed the risks that a tunnel is governed by two separate control centers. Regarding safety in tunnels have emerged with force new technologies such as the fixed sistemas of extinction, automaticos incidents and fire detection systems, and thermal cameras. The tunnels have become complex sistemas where the variables of traffic, environmental quality, and incidents are monitored in real time.