Optimizing Tunnel Asset Management through Multi-Objective Decision Support Tools

The upcoming challenges in the transport infrastructures industry will surely include the maintenance and rehabilitation of the existing tunnels, furthermore, a structured and data-driven approach, aligned with best practices in Asset Management, is essential to ensure continued serviceability while operating within budgetary constraints. Autostrade per l’Italia S.p.A. manages 595 tunnels, half of which were built before 1970. In response to this scenario, the authors launched in 2023 the development of a decision support tool designed to assist in defining and optimizing tunnel maintenance strategies. The primary goal is to reduce subjectivity in the decision-making process and provide a robust, user-friendly platform that supports engineers and asset managers in planning interventions based on objective criteria. The first phase resulted in an internal prototype, that was tested through real business cases, enabling continuous refinement through feedback from daily operations. In early 2024, the project entered its second phase with the development of four objective functions: 1. Structural Condition (STR): current and forecasted tunnel integrity; 2. Economic Efficiency (NPV): net present value of expected benefits and costs; 3. Operational Impact (OP): implications for service continuity; 4. Sustainability (ESG): environmental, social, and governance performance. The tool allows for the optimization of the objective functions and the prioritization of assets that require action in the short- to medium-term, aligning with performance targets and service level agreements. Although still under development, the initiative demonstrates a promising shift toward a more transparent, repeatable, and accountable approach to tunnel asset management. Ongoing work includes refining deterioration and cost models, enhancing ESG assessment criteria, and involving interdisciplinary experts to further strengthen the tool’s reliability and applicability across various contexts.