{ "background": "Municipal infrastructure systems in developing nations face significant challenges from ageing assets, population growth, and climate stressors. Traditional risk assessment methods often lack the flexibility to integrate sparse, multi-source data and quantify uncertainty for long-term planning.", "purpose and objectives": "This study aims to develop and evaluate a novel comparative Bayesian hierarchical model for quantifying risk reduction across diverse municipal infrastructure asset systems. The objective is to provide a robust, probabilistic framework for prioritising interventions and forecasting future risk trajectories.", "methodology": "A comparative study was conducted using national and municipal-level data on water supply, roads, and drainage systems. The core methodological innovation is a Bayesian hierarchical model, $y{it} \\sim \\text{Normal}(\\alphai + \\betat, \\sigma^2)$, $\\alphai \\sim \\text{Normal}(\\mu{\\alpha}, \\tau{\\alpha}^2)$, where $y_{it}$ represents a risk metric for asset $i$ at time $t$, with partial pooling across assets and temporal components. Model inference used Hamiltonian Monte Carlo sampling.", "findings": "The model demonstrated a high predictive capacity, with posterior credible intervals for key risk parameters excluding zero. A principal finding was a projected divergence in risk profiles, where interventions in integrated drainage systems showed a 40% greater median reduction in compound risk scores compared to standalone road projects under modelled scenarios.", "conclusion": "The Bayesian hierarchical framework provides a statistically rigorous and adaptable tool for comparative infrastructure risk analysis, effectively synthesising heterogeneous data to inform strategic asset management.", "recommendations": "Infrastructure agencies should adopt probabilistic, hierarchical modelling for long-term risk planning. Future research should integrate real-time sensor data and socio-economic covariates to enhance model granularity and causal inference.", "key words": "Bayesian hierarchical modelling, infrastructure risk management, asset management, probabilistic forecasting, municipal engineering", "contribution statement": "This paper presents a novel application of Bayesian hierarchical modelling for the comparative, long-term assessment of municipal infrastructure