CONCLUSIONS
Network level infrastructure maintenance decision-making is a multi-factor and multi-criteria problem. It used to be determined based on limited factors and subjective judgment. Analytic Hierarchy Process (AHP) method was selected for determining the weighting of each decision-making factor in this study. It is capable of incorporating all the potential maintenance related factors, considering their relative importance and generating an overall priority ranking index for each road section. A case study on network level pavement maintenance decision-making for the highways was conducted to demonstrate the application of the AHP method. A total of five pavement maintenance decision-making factors were considered, including pavement performance, pavement structure strength, traffic loads, pavement age and road grade.The weighting values of the five factors were determined through AHP method. After the quantification of weighting values of the five factors, the comprehensive ranking value Ui was determined, which indicated the maintenance priority of a road section in network level decision-making process. From the aspect of maintenance cost, the sensitivity analysis results were in accordance with the weighting value of different maintenance decision-making indices. It can be found that the pavement maintenance cost is very sensitive to the change of pavement performance. There are also several problems that can be improved for the application of AHP method. The five indices considered in this study are generally the pavement structural, functional and conditional factors. Several other potentially important factors, including pavement structure type, climatic condition, details of the surface materials, could also be included when the data is available.
