Rural road networks are the backbone of livelihood, humanitarian access, and post-conflict recovery in South Sudan, yet decades of civil conflict have dismantled both the physical infrastructure and the institutional capacity required for systematic maintenance. This study investigates community-centred road maintenance (CCRM) approaches across six war-affected counties in Central and Western Equatoria, drawing on a mixed-methods research design combining structured household surveys (n = 412), key informant interviews with local road committees (n = 38), and field condition assessments of 214 km of rural earth and gravel roads. The study develops and validates a Community Road Maintenance Capacity Index (CRMCI) comprising five dimensions: labour mobilisation capacity, local funding mechanisms, technical knowledge transfer, organisational cohesion, and community ownership. Results demonstrate that counties with CRMCI scores above 65/100 showed road condition improvements of 38–54% over a three-year period, compared to 8–15% improvement in counties relying exclusively on government force-account or contractor-based approaches. A participatory action research framework incorporating gender-responsive labour division, performance-based incentive structures, and indigenous knowledge integration is presented as a replicable model for road maintenance governance in fragile-state contexts. The findings contribute to the evidence base for community-driven infrastructure maintenance in post-conflict sub-Saharan Africa and provide actionable recommendations for the Ministry of Roads and Bridges (MoRB), development partners, and county-level civil authorities.