Mitigating Port-Induced Traffic Congestion in Chattogram: A Theoretical SUMO Simulation Framework for the Agrabad–Freeport Corridor

Abstract

Port-related freight activity, heterogeneous traffic, weak lane discipline, and roadside friction contribute to persistent congestion along major urban corridors in Chattogram, Bangladesh. This study develops an evidence-informed microscopic traffic simulation framework using the Simulation of Urban Mobility (SUMO) platform for the Agrabad–Freeport corridor, with particular focus on the Barik Building–Saltgola section. Five scenarios are considered: the existing-condition baseline, adaptive signal control, lane channelization, a dedicated Non-Motorized Transport (NMT) lane, and a combined strategy. Because corridor-specific traffic counts, signal timings, trajectory data, and validated travel-time observations were unavailable, the study is structured as a theoretical framework rather than a locally calibrated simulation. Published intervention effects were transferred only where sufficiently comparable evidence existed, while unsupported outcomes were retained as theoretical or sensitivity-based projections. Adaptive signal control showed the most comprehensive evidence base, with reported reductions of 13.6% in travel time, 14.3% in intersection delay, 8.9% in queue length, and approximately 9% in both CO₂ emissions and fuel consumption, together with a 47.9% increase in mean network speed. Lane channelization indicated a 10%–30% travel-time reduction based on Bangladesh-specific evidence. In contrast, the dedicated NMT lane revealed a context-dependent safety–capacity trade-off, while the combined strategy was treated as non-additive because the interventions influence overlapping network processes. The framework provides a transparent basis for prioritizing future field data collection, calibration, validation, and integrated scenario testing in a freight-intensive urban corridor.