Diagnosis of Urban Congestion in Bujumbura: Integrating Traffic Counts, Road Network Redundancy, and Public Transport Dynamics

Rapid motorization in African cities has intensified congestion, particularly in compact urban cores such as Bujumbura, Burundi. This study diagnoses the structural, operational, and institutional determinants of Bujumbura's traffic congestion using integrated methodologies combining field traffic counts, network redundancy analysis, and public transport assessment. Empirical surveys conducted between July and August 2025 covered three primary corridors-Avenue de la Révolution, Boulevard de l'Uprona–Avenue du 13 Octobre, and the Aru–Ariwara corridor. Results show that all major corridors operate under Level of Service (LOS) F, with average volume-to-capacity ratios exceeding 1.0 and mean delays above 100 seconds per vehicle. Network analysis revealed a connectivity index (γ) of 0.27 and a cyclomatic number (μ) of 18, indicating weak redundancy and limited alternative routes. Informal public transport systems-minibuses and motorcycle taxis-dominate the mobility landscape, contributing over 70% of total vehicular flow. Institutional fragmentation among transport agencies further exacerbates inefficiency. The study recommends an integrated approach comprising corridor optimization, establishment of a metropolitan transport authority, route rationalization, and non-motorized transport promotion. Findings provide a replicable diagnostic framework for medium-sized African cities facing similar congestion crises.