Budgeting for Bituminous Road Pavement Maintanance: Case Study Poids Lours Roads in Rwanda

Abstract

Road development and maintenance contribute to significant preservation of road performance by keeping road in good riding quality and contribute to the economic development of a country. However, road network deterioration, decreased functional and structural performance are common observable problem cases in Rwanda associated with lack of maintenance plan, budgeting tool and maintenance expenses prediction tool. This thesis aims to assess road development and maintenance options used in Rwanda and provide budgeting tools in the management system of flexible paved roads. Data used in this study were collected in two steps: the first step was the collection of primary data from different road projects feasibility studies and the second step was the processing of primary data in HDM-4 for deterioration trends and economic analysis of studied road projects and the outcome was generated and gave secondary data. Analysis was done to assess the economic viability of road development and maintenance practices for flexible paved roads used in Rwanda and riding quality in terms of deterioration trends for an analysis period of 20 years. Using multiple regression analysis and ANOVA, quantitative and qualitative analysis was done to develop a road maintenance cost (RMC) budgeting model, and to test the model validity, a comparison was made to compare observed values and predicted values. The results from this study prove that maintaining roads at an early stage of deterioration is a good practice. Maintenance enhances the economic return of road development and maintenance investment as explained by NPV and NPV/RAC ratio. The length of the road, the width of the road, AADT, and average altitude are explanatory variables for road maintenance cost and were found to be statistically significant as depicted by P-value (at 95% CL, P-value< 0.001) and other statistical parameters such as t-stat to test independent variable significance. The road budgeting model equation developed in this study shows high significance for future discounted RMC prediction for 20 years of the analysis period (AP) as depicted by its high correlation coefficient R2 of 0.965. The model shows high validity to predict future RMC as shown by the high correlation coefficient (R2-adjusted of 0.932) between observed and predicted values. This study revealed the importance of the proper practice of maintenance practices proposed in Rwanda and shown that regular maintenance practice application can enhance high economic return, keeping riding quality as good during lifecycle period of road and possible extension of lifecycle period of road. The budgeting tool developed in this study is recommended to be used by road agencies to properly predict discounted RMC in 20 years of AP for budgeting, planning, allocation, and fund requirement study at desk study and have to be used by all road agencies with a regular road inventory to assess road condition and deterioration analysis to recommend responsive maintenance.