Development of a Multi-Criteria Indicator System for Safe Site Selection of Long Mountain Tunnels in Highway Projects

The construction of long and large-scale mountain tunnels represents a pivotal component in highway infrastructure, where site selection plays a decisive role in ensuring both construction safety and long-term operational stability. Nonetheless, factors such as intricate geological conditions, environmentally sensitive terrains, and fluctuating economic contexts introduce considerable uncertainty into the decision-making process. To tackle these complexities, this study proposes a structured multi-criteria evaluation framework by establishing a targeted indicator system for tunnel siting in mountainous regions. The system incorporates a balanced set of criteria encompassing social, economic, environmental, and technical safety aspects, aiming to reflect the multifaceted nature of siting risks comprehensively. By formulating this index-based decision support tool, the research enables a more transparent and rational assessment of alternative locations. The framework not only facilitates improved decision reliability under uncertainty but also contributes to enhancing risk management practices in complex terrain infrastructure planning.