## 3 Benefit Components
### Maintenance Benefit Evaluation System Based on AHP Model  
The various evaluation indicators for evaluating maintenance benefits have already been proposed in the previous text, which makes it crucial to use comprehensive analysis and evaluation of each indicator. Given the diversity of maintenance benefit evaluation objectives, traditional weighting methods find it difficult to coordinate the weights of various indicators. The analytic hierarchy process (AHP) can effectively solve decision-making problems with complex structures and multiple decision-making criteria. It is a systematic decision-making method that transforms problems from qualitative analysis to quantitative analysis and can effectively calculate the weight of the comprehensive evaluation model for maintenance benefits. According to the basic usage process of the AHP method, it can be divided into three steps: constructing a hierarchical structure model; construct a judgment matrix; model weight calculation. 1 Hierarchy model. AHP reflects the hierarchical relationship of the model through the established hierarchical model. Among them, the highest level of the model is the target level, that is, maintenance benefits, the middle layer is the criterion layer composed of maintenance economic benefits; social benefits, and environmental benefits; and the lowest level is the index layer composed of various benefit indicators, as shown in Figure 2.  
2 Constructing a judgment matrix  
The construction of the judgment matrix is the core part of the analytic hierarchy method, and the decision-makers are based on the AHP maintenance benefit evaluation hierarchy model, comprehensive advice, research, and calculation results of owners and experts, and compare the elements of the next layer one by one based on the goals of the previous layer, analyze the relative importance of the factors of each layer, and determine the importance of the next layer of elements to the goals of the previous layer. The construction method of each layer judgment matrix often adopts the 1-9 scale method shown in Table 9.  
Figure 2: AHP Maintenance Benefit Evaluation Hierarchy Model. a. Criterion layer judgment matrix  
The criterion layer mainly includes three aspects of benefits: economic benefits, social benefits, and environmental benefits. The judgment matrix of the criterion layer is shown in Table 10[23]:  
b. Indicator layer judgment matrix  
In the construction of the indicator layer judgment matrix, the economic benefit indicator adopts the performance improvement value; the social benefit indicators adopt service life extension and road user cost savings; and the environmental benefit indicators adopt the cost savings of energy consumption and environmental emissions[36]. For road user cost savings, it is very necessary to save users' time while driving on the road. At the same time, on the basis of saving time, it is necessary to ensure the safety of drivers and passengers before considering the operating cost of the vehicle [8]. Therefore, the judgment matrix of the social benefit indicator layer is constructed as shown in Table 11. The judgment matrix for constructing the indicator layer of environmental benefit indicators is shown in Table 12[36]. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**Maintenance Benefits**} & \multirow{2}{*}{**Economic Benefits**} & \multirow{2}{*}{**Social Benefits**} & \multicolumn{2}{c}{**Environmental Benefit**} \\ \hline Economic benefits & 1 & 2 & 2 \\ Social benefits & 1/2 & 1 & 1 \\ environmental benefit & 1/2 & 1 & 1 \\ \hline \hline \end{tabular}
\end{table} 
Table 10: Judgment Matrix of Criterion Layer.