Providing the Maintenance and Rehabilitation Model of Primary Road Network Using Life Cycle Cost Analysis - Case Study South Khorasan Province

The rapid development of roadways and the limited budget require establishing an effective pavement management system. The paper aimed to utilize the Life Cycle Cost Analysis (LCCA) and implement HDM-4 Software to determine the most appropriate maintenance and rehabilitation technique in part of a network in South Khorsan Region in Iran. In doing so, initial homogenous segments were assigned based on Pavement Condition Index (PCI), International Roughness Index (IRI) and maximum deflection under the center of the load plate in Falling Weight Deflectmeter (FWD) device. The final homogenous segments were determined based on the selected maintenance and rehabilitation work items. The effects of each rehabilitation alternative on roughness and the attributed costs were analyzed at the network level. Finally, the effects of change in the budget heads and the discount rates were investigated performing sensitivity analysis. Results indicated that all the maintenance and rehabilitation alternatives, except for the base method, decreased the IRI values. Furthermore, the higher amount of road user costs, compared with road agency costs, indicated the importance of considering the user cost in LCCA. With increasing the discount rates, the proposed work program would change. Taking into consideration various maintenance alternatives, the importance of inserting the correct discount rate in LCCA was confirmed. Regarding allocated budget for the analysis period, it was revealed that the allocated 100 billion Rials in the first year of the analysis period, followed by 10 percent annual increase, was enough for implementing the proposed program. With further analysis, it was found that the 700 billion Rials (54 percent of the total allocated budget) was considered a minimum budget required for application of the proposed work program, saving large amounts of national financial sources.