Prioritizing Metro System Development for Sustainable Urban Transport in Metropolitan Areas in Iran: A Multi-Criteria Approach

With rapid urbanization and increasing transportation demands, the development of metro systems has become a critical priority for sustainable urban mobility. However, determining which metropolitan areas should be prioritized for metro investment remains a complex, multi-faceted decision-making challenge. While existing studies highlight the benefits of metro networks, a systematic framework for ranking cities based on diverse urban, economic, and environmental criteria is lacking. This study addresses this research gap by employing the Analytic Hierarchy Process (AHP) within a Multi-Criteria Decision-Making (MCDM) framework to evaluate and rank four major Iranian cities, Qazvin, Urmia, Kerman, and Rasht, for metro system development. An expert-driven approach selected six key indicators: population, air pollution levels, urban traffic congestion, number of satellite cities, maximum city span, and urban bus fleet size. Pairwise comparisons and expert assessments were conducted using Expert Choice software to determine criteria weights and rank the cities accordingly. The findings indicate that Kerman is the most suitable city for metro expansion, followed by Urmia, Qazvin, and Rasht. Sensitivity analysis confirmed the robustness of the ranking, revealing that air pollution levels and traffic congestion were the most influential factors. This study contributes to urban planning by providing a structured, data-driven methodology for metro system prioritization, supporting evidence-based policymaking. Future research should integrate economic feasibility assessments, real-time mobility data, and public perception surveys to refine metro investment strategies further and enhance urban sustainability.