PRIORITIZATION AND ASSIGNMENT OF OPTIMAL MAINTENANCE STRATEGY OF PAVED ROAD SEGMENTS BY USING HDM-4 TOOL (A CASE STUDY IN SODO DISTRICT OF THE ETHIOPIAN ROADS AUTHORITY

Abstract

Efficient Pavement management maintenance system are backbone for an optimal maintenance strategies. Currently, 36% of the road segments under Sodo road network maintenance district (RNMD) are also in poor condition of performance. The poor state of the road network is caused mainly because of not applying timely and optimal maintenance. In addition to this, in countries like Ethiopia, a yearly limited budget is insufficient to maintain all deteriorated roads in the country.To counteract this problems, this study was aimed at setting prioritization and assignment of optimal maintenance strategy for 10 paved road segments of 690Km under Sodo RNMD by using highway development and management tool (HDM-4). To meet this objective pertinent data were collected from Sodo RNMD and many offices. Then, the collected data under different input type were entered manually into the HDM-4 software to make it ready for economic analysis. Four types of maintenance alternatives with different types of maintenance standards and intervention levels were used in this study for comparison of alternatives. After HDM-4 project analyses were carried, among the alternatives, an alternative with a higher value of net present value per cost (NPV/C) was considered as an optimal maintenance alternative for each road segment. Among the maintenance alternatives alternative two (Routine + SBST + 50mm asphalt concrete overlay) has generated a higher value of NPV/c than other alternatives and were considered as an optimal maintenance alternative for 5 road segments. Finally, the prioritization of segments for annual maintenance according to profitability was done by comparing the internal rate of return (IRR) values of each segment with an optimal alternative. In this regard, the Alaba to Sodo road segment was found to be a project with the highest value of IRR= 393.6% and should be prioritized first for maintenance. The remaining segments were prioritized likewise based on their respective IRR values. So It was found that using HDM–4 analysis in the process of establishing road maintenance strategies will reduce lifetime cost and increase benefits and profitability