## 5 Conclusions  
The operational safety situation of long and large highway tunnels is severe. In this study, a partitioned assessment index system for evaluating the operational safety risk of long and large highway tunnels was constructed from the perspective of risk management. To address the challenges of the traditional AHP method, such as obtaining expert opinions quickly and effectively and dealing with strong subjectivity and bias, this paper proposes the adoption of the Triangular Fuzzy Analytic Hierarchy Process (FAHP) to determine the weights of the evaluation indicators for tunnel operational safety risk. Additionally, the paper combines the Triangular FAHP with Set Pair Analysis to construct a risk assessment model for the operational safety of long and large highway tunnels. The advantages of this approach are as follows:  
1. Introducing a new expert system analysis method to collect expert opinions and proposing a new fuzzy number determination method for transforming expert opinions. This process is simple and clear, effectively simplifying the tedious and time-consuming pairwise comparison scoring process in expert questionnaires. Moreover, the judgment matrix determined by this method can better satisfy the consistency requirements. 2. The Triangular Fuzzy Analytic Hierarchy Process (FAHP) employs triangular fuzzy numbers instead of single values to express expert opinions, considering the influence of different perspectives among decision-makers and reflecting the ambiguity and uncertainty inherent in the expert judgment process. This approach better aligns with the real-world decision-making scenario of experts and makes the risk assessment results more reasonable and well-founded. 3. By establishing a tunnel operational safety risk assessment model based on the Triangular Fuzzy Analytic Hierarchy Process (FAHP) and Set Pair Analysis (SPA), the similarity between the indicator set and the standard set is compared using Set Pair Analysis. This ultimately achieves a combination of subjective weighting and objective evaluation, improving the accuracy of risk assessment for the operational safety of long and large highway tunnels. Using the long and large tunnels within the G1523 Yongguan Expressway section from K0 + 000 to K46 + 920 as an engineering example, a comparative evaluation was conducted using both the Triangular Fuzzy Analytic Hierarchy Process (FAHP) and the traditional AHP. The results revealed that the trend of evaluation indicator weights determined by the Triangular FAHP was essentially consistent with the results obtained from the traditional  
Figure 12: Tunnel partition risk levels. (**a**) Sijiao’an Tunnel; (**b**) Jiaodong’ao Tunnel; (**c**) Anjishan Tunnel. Note 1: The colors green, blue, yellow, orange, and red, respectively, correspond to risk levels I, II, III, IV, and V.  
AHP. The tunnel risk levels determined based on the Triangular Fuzzy Analytic Hierarchy Process (FAHP) align with the actual operational safety status of the tunnels. Moreover, the risk levels assessed by the Triangular FAHP are relatively more conservative compared to the results obtained from the traditional AHP. This demonstrates the rationality and accuracy of the proposed risk assessment method for the operational safety of long and large highway tunnels in this study. By conducting a detailed analysis of the operational safety risk assessment results, identifying the causes of problems and weak points in operational management, and proposing targeted corrective measures, timely resolution of safety hazards in long and large highway tunnels can be achieved. This continuous improvement in risk management will help reduce the occurrence of safety accidents in long and large highway tunnels. However, the evaluation method proposed in this study still has limitations. The risk assessment method presented in the paper is still in the research stage and requires extensive practical experimentation for continuous validation and refinement.