Wrong polycentricity-right polycentricity? : insights from an empirical study in Tehran metropolitan region, Iran

This research delves into the complexities of assessing polycentric development, focusing on Tehran's city-region. Using a systematic analytical approach, we examine geographical boundaries, center thresholds, and measurement indicators over time. Our findings highlight the crucial role of geographical boundaries in understanding polycentricity. We show that the choice between administrative and functional boundaries significantly affects polycentricity measurement, underscoring the importance of careful boundary selection. Moreover, our investigation reveals that specific center selection thresholds do not decisively impact polycentricity measurement. We emphasize the adaptable nature of polycentricity indicators across different boundary and center configurations. However, interpreting polycentricity patterns depends not only on indicator selection but also on the intricate interplay of boundaries and centers. These interconnected dimensions provide comprehensive insights into Polycentric Urban Development (PUD), advocating for improved and harmonious approaches. Our study underscores the delicate balance among boundaries, centers, and indicators in understanding PUD. It suggests refining processes and scales, delineating regions and centers meticulously, and focusing on size distribution and interaction patterns among centers to achieve a more accurate approximation of reality. The polycentricity evaluation of Tehran's metropolitan region can inform revisions to current approaches, frameworks, and indicators, ultimately enhancing the metropolitan regions' evaluation methods, planning, and territorial policy.