Core Viewpoint - The recent announcement from Ningbo's authorities regarding the need for re-approval of previously approved but unimplemented subway projects signals a significant shift in subway construction policies across various cities in China, indicating a tightening of regulations and a focus on quality and efficiency over mere expansion [2][4][12]. Summary by Sections Policy Changes - The National Development and Reform Commission has introduced new requirements for cities with previously approved subway projects that have not yet been implemented, necessitating re-approval for new planning submissions [2][4]. - The tightening of subway construction policies has been a gradual process, starting with the 2018 "Document No. 52," which raised the economic and fiscal thresholds for cities seeking to initiate subway projects [2][3]. Construction Criteria - New criteria for urban rail transit project submissions include a minimum public finance budget revenue of 30 billion yuan, a regional GDP of 300 billion yuan, and a resident population of at least 3 million [3]. - The focus has shifted from expanding the scale of subway construction to prioritizing quality and efficiency, with cities now required to demonstrate the ability to implement previously approved projects before applying for new ones [4][12]. Impact on Cities - Many cities are now under pressure to complete previously approved subway lines rather than pursuing new projects, as failure to meet construction standards could result in losing the right to build even approved lines [4][5]. - Cities like Chengdu are urged to accelerate the implementation of their approved subway lines, while others face challenges due to debt or insufficient passenger flow [5][6]. Investment Trends - The investment in urban rail transit construction peaked at 628.6 billion yuan in 2020 but has since declined, with 2023's investment at 521.4 billion yuan, a decrease of 17.05% from the peak [7]. - The new policies are expected to further limit the number of cities eligible for subway construction, as the thresholds for GDP and fiscal revenue are anticipated to increase significantly [11][12]. Urbanization and Future Directions - The ongoing tightening of subway construction policies reflects a broader transition in urbanization from rapid growth to stable development, emphasizing the need for cities to focus on optimizing existing infrastructure rather than expanding it [12][14]. - The future of urban competitiveness will rely more on enhancing existing services and infrastructure quality rather than merely increasing the quantity of subway lines [16][17].