Framework for Assessing the Climate Vulnerability of Unpaved Roads in Sierra Leone

Phodie Musa Kamara^1*Yaw Adubofour Tuffour²Frank Baffour-Ata³Daniel Atuah Obeng²

• ¹Sierra Leone Roads Authority (SLRA), PMB 1324, PWD Kissy,, FREETOWN, Sierra Leone
• ²College of Engineering, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
• ³Department of Environmental Science, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana

Unpaved roads account for 80% of the global road network and 90% of the road network in developing countries, yet methodologies for assessing their climate vulnerability remain limited. In Sierra Leone—ranked among the world's most climate-vulnerable nations, this challenge is especially urgent, as high-traffic secondary roads, which account for 96% of its core network and serve as the backbone of rural connectivity, market access, and social inclusion. Despite their importance, no structured framework currently exists to guide the management of climate-related risks to these roads. This study addressed the gap by first evaluating international climate risk and vulnerability assessment frameworks, exposing their limited applicability in resource-constrained environments like Sierra Leone due to their reliance on extensive datasets, proprietary software, and advanced computing infrastructure. To respond, a context-specific, five-phase framework was developed, adapted from the Intergovernmental Panel on Climate Change (IPCC)–endorsed vulnerability model. The framework was designed to align with Sierra Leone's infrastructure conditions, data realities, and institutional capacities. Moreover, it does not require costly proprietary software or advanced computing infrastructure. Unlike rigid, data-intensive international models requiring costly software and high-end computing, the proposed five-phase framework uses cost-effective, open-source tools (QGIS, QField, PostGIS, cloud storage, and Power Business Intelligence). It integrates index-based, spatial, and stakeholder-driven methods to produce three composite indicators: road condition deficiency, maintenance efficacy, and criticality. Case studies in Sierra Leone confirmed its effectiveness in identifying vulnerable unpaved road segments and informing adaptation strategies. Nationally, it provides the first structured framework for managing climate risks to road infrastructure, supporting the National Roads Agency. Globally, it offers a transferable, resource-efficient, community-driven model for embedding climate resilience into transport planning across the Global South.