Development of models for optimal road maintenance fund allocation : A case of Ghana

The research was aimed at the development of an optimal road fund allocation model for road maintenance to three road agencies in Ghana. The objective was to compare a novel model by multicriteria analysis (MCA) with deterministic outcome and a model based on preferential analysis to determine optimality. The deterministic model was efficiency based with quantitative analysis from a decision maker’s perspective whilst the approach by preferential analysis was equity based with qualitative analysis from stakeholder perspective. The input parameters of the deterministic model were based on the value function method (VFM) and the concept of efficiency frontier. It determined a scaler index for the proportionate allocation of road fund by road type. It was based on a set of attributes including road length, traffic, pavement roughness and percentage of work achievement. The concept of efficiency frontier was used to sub divide the proportion of funds allocated by road type into economic efficiency and equity components based on the Net Present Value/Capital, Vehicle Operation Cost (VOC) and income. The values of the selected attributes were generated from the outputs of HDM-4 analysis. The model based on the preferential analysis was set on the Analytical Hierarchy Process (AHP). It involved pairwise comparison of defined criteria and sub criteria by stakeholder priority at national, district and community levels. Priority vectors were estimated for road fund allocation into efficiency and equity proportions by road type. A comparison of the outputs of the two models on the basis of the impact on pavement roughness performance indicated the stated preference based model yielded better impacts than the model with deterministic approach. It was concluded that road fund allocation based on a well logically determined value judgement with mathematical analysis yields better results.