Methodological Evaluation of Transport Maintenance Depot Systems in South Africa Using Difference-in-Differences Approach

Transport maintenance depots (TMDs) play a crucial role in ensuring efficient urban transport systems in South Africa. These facilities are essential for maintaining and repairing public transportation vehicles, thereby reducing operational downtime and enhancing service reliability. A Difference-in-Differences (DiD) approach will be employed, comparing pre- and post-intervention periods for depots within the study area with a control group of similar depots in other cities. Econometric models will estimate cost savings attributable to TMD interventions. The DiD analysis suggests that TMDs can reduce vehicle maintenance costs by approximately 15% over three years, though this varies by depot size and location. The study concludes that the DiD model provides a robust framework for measuring cost savings from TMD interventions. This could inform policy decisions to enhance urban transport efficiency in South Africa. Transport authorities should prioritise investment in larger, more centrally located depots to maximise cost savings and service reliability. Difference-in-Differences, Transport Maintenance Depots, Cost-Effectiveness Analysis, Urban Infrastructure The maintenance outcome was modelled as $Y_{it}=\beta_0+\beta_1X_{it}+u_i+\varepsilon_{it}$, with robustness checked using heteroskedasticity-consistent errors.