Optimizing Waste Collection in Lagos Through Transfer Stations and Routing Models—Impacts on Efficiency, CO₂ Emissions, and Costs

Rapid urbanization in developing megacities like Lagos, Nigeria has led to surging waste generation and overstretched collection systems. Inefficient routes, traffic congestion, and infrastructure deficits undermine timely waste collection, resulting in excessive vehicle mileage, high fuel costs, and environmental pollution. This study models an optimized waste collection network for Lagos’ Lekki-Epe region by introducing a strategically located waste transfer station and optimized routing. The Authors in this paper collected and analyzed eight months of waste vehicle movement data from Lagos and developed a simulation using Visual Basic for Applications and the Google Maps API to compare scenarios with and without a transfer station. Four scenarios were tested, examining factors such as a 20-minute route delay threshold, increased transfer truck capacity, and off-peak collection timing. The optimal transfer station location was found to be approximately 45 km along the Lekki-Epe corridor from the landfill, which reduced total collection vehicle travel time by about 42.6%. This corresponds to an annual reduction of roughly 363,283 km in travel distance, yielding an estimated decrease of approximately 653.9 tonnes of CO₂ emissions per year. Cost-wise, the coordinated use of a transfer station is projected to lower fuel use and vehicle wear, translating into significant operational savings for private waste contractors. Introducing a transfer station could also modestly reduce urban traffic congestion by removing many refuse trucks from long-haul routes. The implementation of optimally placed transfer stations combined with route optimization can substantially improve collection efficiency, lower greenhouse gas emissions, and reduce costs in Lagos waste management system. These findings provide a model for other rapidly urbanizing cities seeking sustainable waste infrastructure improvements.Keywords: Municipal solid waste (MSW); Transfer station siting; Routing optimization; Google Maps Directions API; Excel VBA simulation; Travel time and distance reduction; greenhouse gas emissions; Operational cost savings; Public–private partnerships (PSP).