A comparative life cycle cost analysis for open and closed road drainage infrastructure in Nakawa Division Kampala.

Abstract

The idealized cost framework for road infrastructure involves low maintenance costs while providing better performance of roads and drainage systems, however, the maintenance system between roads and drainage is often disintegrated, thereby increasing road maintenance costs. Such, has been the reason for the investigation of the impact of drainage towards the road’s maintenance particularly since poor drainage significantly contributes to various road defects. Therefore, effective drainage is not only of paramount importance, but cannot be overemphasized, this study explored the costs involved in strategic decision making concerning the adoption of closed and open drainage systems by implementing a life cycle cost analysis considering the construction, maintenance, and demobilization of either system. Additionally, a sensitivity analysis was further implemented to analyses the effect of variation of real discount rates on the total present value. The implemented Life Cycle Cost Analysis (LCCA) performed illustrated that the NPV for closed drainage decreases as the discount rate increases, ranging from 3,859,675,689 UGX at 2% to 3,088,238,164 UGX at 6%. Similarly, for open drainage, the NPV decreases from 1,341,579,952 UGX at 2% to 1,109,088,706 UGX at 6%. Additionally, on average, the cost ratio of open drain to closed drain NPV remains relatively constant across different discount rates, ranging from approximately 34.76 to 35.91. This suggests that, regardless of the discount rate, open drainage is approximately 35 times less costly than closed drainage over the life cycle considered in the analysis. This study therefore underscores the overall cost-effectiveness of open drains despite the preference for closed drains in areas with high land costs.