{ "background": "Municipal infrastructure asset management in sub-Saharan Africa faces significant challenges in tracking the adoption and performance of engineered systems. Existing evaluation methods often lack robust counterfactual analysis, limiting the ability to attribute outcomes to specific interventions or policies.", "purpose and objectives": "This study aims to develop and validate a quasi-experimental methodological framework for evaluating the adoption rates of municipal infrastructure systems. The primary objective is to quantify the causal effect of a national asset management policy on the uptake of standardised systems across urban local governments.", "methodology": "A difference-in-differences (DiD) model is employed, using panel data from urban councils. The treatment group consists of councils that implemented the national policy, while the control group comprises those that did not. The core model is specified as: $Y{it} = \\beta0 + \\beta1 \\text{Treat}i + \\beta2 \\text{Post}t + \\delta (\\text{Treat}i \\times \\text{Post}t) + \\epsilon_{it}$. Inference is based on cluster-robust standard errors at the council level.", "findings": "The policy intervention had a statistically significant positive effect on adoption rates. The DiD estimator, $\\delta$, was 0.18 (95% CI: 0.12, 0.24), indicating an 18-percentage-point increase in the probability of system adoption attributable to the policy. The parallel trends assumption was validated using placebo tests.", "conclusion": "The difference-in-differences model provides a rigorous methodological tool for evaluating infrastructure system adoption, successfully isolating the policy's causal impact. This approach offers a substantial improvement over descriptive trend analyses.", "recommendations": "Infrastructure policy evaluations should incorporate quasi-experimental designs to strengthen causal claims. Urban councils should institutionalise longitudinal data collection to support such analyses. The methodology is recommended for replication in similar contexts.", "key words": "asset management, difference-in-differences,