Impact Assessment of Roadside Parking on Traffic Congestion and Proposed Solutions in Kigali’s Central Business District (CBD), Case study: Nyabugogo

Abstract

Urban traffic congestion remains a pressing challenge in many rapidly developing cities, particularly within Central Business Districts (CBDs) where land use intensity, motorization, and limited infrastructure converge. In Kigali, Rwanda, Nyabugogo has emerged as a critical congestion hotspot, exacerbated by excessive roadside parking, informal transport activity, and inadequate off-street parking utilization. This study investigates the influence of roadside parking on traffic congestion along two key corridors; KN1 and KN7 Roads, in Nyabugogo, and proposes evidence-based strategies to improve urban mobility and curbside management. A comprehensive seven-day traffic observation was conducted using video-based data collection methods, capturing hourly traffic volumes, parking occupancy, queue lengths, vehicle speeds, and pedestrian conflict events. These data were analyzed using correlation analysis, linear regression, and one-way ANOVA to quantify the effects of parking activity on traffic flow performance. The study found a strong positive correlation between roadside parking occupancy and vehicle delay, with R2 values frequently exceeding 0.90. ANOVA results demonstrated statistically significant differences in average speeds across morning, midday, and evening periods, confirming the temporal dependency of congestion driven by parking behaviors. KN1 Road exhibited greater flow instability, longer queues, and more pedestrian conflicts compared to KN7 Road, due in part to its narrow cross-section and intense curbside demand. Despite a robust legal and institutional parking framework in Kigali, the research identified serious operational shortcomings, including static pricing, weak enforcement, and poor signage. Although over 5,300 off-street parking spaces exist, only 64% are utilized, while on-street spaces operate at nearly full capacity. The study highlights how this imbalance fuels cruising behavior, illegal parking, and pedestrian safety risks, particularly during peak periods. The current revenue-sharing structure; where the majority of parking fees go to the private operator (MISIC), further limits the city’s ability to invest in enforcement and infrastructure improvements. To address these challenges, the study recommends a set of targeted interventions, including demand-responsive parking pricing, time-based curb restrictions, improved signage, digital enforcement systems, real-time parking information tools, and better sidewalk and curbside vi designs. These solutions align with international best practices from cities such as San Francisco, Singapore, and Tokyo, and are tailored to Kigali’s urban context. The study offers valuable insights for policymakers, urban planners, and transport engineers in Rwanda and other rapidly urbanizing African cities. It contributes a replicable methodological framework for analyzing the parking-congestion relationship and emphasizes the role of parking policy in sustainable urban mobility planning. Further research is recommended to expand the geographical scope of analysis across Kigali’s broader CBD and secondary centers, incorporate nighttime parking behavior, and integrate qualitative data from road users through surveys or interviews. Additionally, simulation-based modeling and economic impact assessments of proposed parking reforms could offer deeper insights to guide future policy implementation. Ultimately, this study reinforces the critical importance of integrated parking management in reducing urban congestion and improving traffic safety in African city centers undergoing rapid urbanization.