Characterising the structural pattern of urban road networks in Ghana using geometric and topological measures

Road networks are an integral part of any human settlement, facilitating the movement of people, goods, and information. The structural arrangement of a road network can have a profound impact on its performance, mobility and access to critical infrastructure. This study takes advantage of a computational network science approach to examine the structural configuration of road networks using geometric and topological descriptions in districts covering 10 regional capitals in Ghana. The majority of urban road networks were found to follow a radial pattern at the global scale, with either a gridded or a branching configuration at the local scale. Only road networks in Accra and Kumsi are fine grained and of comparable density to other global cities, based on intersection and street densities. Structural indicators such as circuity, clustering, page rank, degree centrality, and betweenness centrality for urban roads in Ghana were found to be comparable to other global cities. Given the lack of adequate infrastructure for traffic monitoring in Ghana, the spatial distribution of betweenness centrality could be part of the critical resource to provide insight for traffic management. These findings provide the basis to inform transportation planning and management on critical issues, particularly, based on the spatial distribution of betweenness centrality it is possible to identify problematic locations within the road network which are most vulnerable to traffic congestion.