PSI - Issue 84

Enrico Mittiga et al. / Procedia Structural Integrity 84 (2026) 867–873

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Fig. 2. Tunnel sensitivity to geological hazard.

Classification by age of road tunnels on Anas network permits to highlight a large number (more than 25% of total amount) of structures over the age of 50 years. Almost 16-18% of structures are practically with no information about their age (Fig. 3).

Fig. 3. Anas tunnels by age.

Considering the high geological sensitivity of the Italian territory, the exposure of road infrastructure to natural hazards, the high level of traffic and the age of existing structures, proper management of tunnels is of paramount importance to ensure the safety and smooth operation of the network. Specific inspection and maintenance strategies have been implemented, in accordance with the regulatory framework of the Ministry of Infrastructure ‡ (2022), to assess the structural health and safety of each tunnel. Considering the results of the inspection activities, it is possible to clearly identify the needs for renovation and safety improvements and plan them appropriately. However, any tunnel renovation work causes disruption and traffic interruptions. Given the high level of traffic on most of the roads managed by Anas, the choice of renovation techniques able to reduce the duration of road closures as much as possible is essential to minimize the impact on road traffic.

‡ Ministry of Infrastructures Decree no. 247 (2022). Guidelines for risk management, safety evaluation and monitoring for road tunnels.