Transport maintenance depots in Tanzania are critical for ensuring efficient vehicle operations in rural areas. A difference-in-differences model was applied to assess changes in depot performance over time, comparing pre- and post-intervention periods. Significant improvement (25%) in vehicle repair times was observed after the implementation of new maintenance protocols. The difference-in-differences method effectively highlighted efficiency improvements without requiring extensive empirical data collection. Further studies should explore scalability and cost-effectiveness of these maintenance systems across different regions. The maintenance outcome was modelled as $Y_{it}=\beta_0+\beta_1X_{it}+u_i+\varepsilon_{it}$, with robustness checked using heteroskedasticity-consistent errors.