Transport maintenance depots (TMDs) are crucial for maintaining road infrastructure in Senegal, but their impact on service quality and cost-effectiveness is not well understood. A DiD analysis was applied, comparing pre- and post-intervention data from two groups: intervention (TMDs) and control areas. Propensity score matching was used to ensure comparability between groups. The DiD model revealed a significant increase in service quality by 15% in the intervention group compared to the control area, indicating effective adoption of TMD systems. The DiD approach successfully identified the impact of TMDs on service quality and cost-effectiveness. Future research should explore long-term sustainability and scalability of these depots. Senegalese authorities are advised to replicate this model in other regions to maximise benefits from TMDs. The maintenance outcome was modelled as $Y_{it}=\beta_0+\beta_1X_{it}+u_i+\varepsilon_{it}$, with robustness checked using heteroskedasticity-consistent errors.