Evaluating Traffic Congestion Reduction through BRT to Monorail system Transition: A SUMO-Based Microscopic Simulation Study in Tehran

Tehran faces critical urban mobility challenges with over ۴ million vehicles causing severe traffic congestion, reducing average speeds below ۲۰ km/h. This paper presents a microscopic traffic simulation study evaluating the replacement of Tehran's ۱۷۹ km Bus Rapid Transit (BRT) network with an elevated suspended monorail system to achieve measurable congestion reduction. The methodology employs SUMO (Simulation of Urban Mobility) software version ۱.۶ for microscopic traffic modeling. The study area is Basij Highway corridor (Line ۳ BRT), spanning ۱۳.۵ km with ۲۴ stations serving ۱۶۰,۰۰۰ daily passengers. The statistical population comprises all corridor users during peak hours. Traffic demand was calibrated to ۱,۰۰۰ vehicles per hour plus ۶۰ BRT buses, with modal shift modeling using multinomial logit models. Key findings demonstrate ۲۴.۸% reduction in average travel time (from ۴۰ to ۳۰ minutes), ۷۸.۴% decrease in traffic density, ۱۳ percentage point modal shift from private vehicles (۲۷% to ۴۰% public transit share), and ۳۳.۹% reduction in CO₂ emissions. Economic analysis reveals capital costs of $۵۰-۱۰۰ million per kilometer with ۱۵–۱۸-year return on investment period despite operational savings of $۳۵۰,۰۰۰-۵۰۰,۰۰۰ per kilometer annually. The study provides quantitative evidence supporting grade-separated transit as an effective congestion mitigation strategy for dense megacities.

کلیدواژه ها:

Traffic congestion ، SUMO simulation ، Modal shift ، Suspended monorail ، Urban transportation