Optimal Pavement Maintenance Strategies for Addis Ababa City Road Network, Analysis Using HDM4

In developing countries like Ethiopia where the traffic growth and axle loading is growing,
deterioration of highways is very fast. This increased traffic demands multilane highways with
proper maintenance time to time. During the process of road network maintenance and
rehabilitation, road authorities strive to select an optimum maintenance strategy from a number of
alternatives. This selection may be obtained only through a realistic approach. An economically
acceptable maintenance strategy may be selected among a number of maintenance alternatives. It
can be done through the analysis of costs and benefits by comparing the various maintenance
alternatives with the help of Highway Development and Management tool (HDM-4). This paper
specifically addresses flexible pavement, including two principal arterial streets under the
administration of Addis Ababa city Roads Authority. The roads include road from Gotera
Interchange to Meskel Square and from Iran Embassy to Bisrate Gebriel. These roads are divided
into different sections and the sections are in turn divided into segments each having 100m length.
The Study involves data collection, data analysis and the selection of optimal maintenance strategy
by using project analysis component of HDM-4 for the road sections under consideration. Four
types of maintenance alternatives including Scheduled patching, overlay, thin lay and slurry seal
were assigned. The optimum maintenance strategy has been selected by comparing Discounted
Net Present Value, Road Deterioration (Roughness progression) and Emission by vehicle Report.
The results of the analysis has shown that scheduled patching and overlay is the optimal
maintenance alternative for both of the selected road networks. It is expected that the information
contained in this paper would be a base line to develop optimal maintenance management strategy
principal arterial streets in Ethiopia