Core Viewpoint - The approval process for urban rail transit projects is tightening, as evidenced by the delay in Ningbo's fourth subway phase planning due to insufficient passenger flow intensity, indicating a shift in policy direction after years of rapid expansion in urban rail transit [1][2][3] Group 1: Current Status of Urban Rail Transit - As of the end of 2024, 58 cities in mainland China will have operational rail transit systems, with 361 lines and a total operational mileage of 12,160 kilometers, including 9,306 kilometers of subway lines [1] - Ten years ago, in 2015, only 26 cities had operational rail transit, with 116 lines and a total mileage of 3,618 kilometers, including 2,658 kilometers of subway lines [1] Group 2: Challenges Faced by Urban Rail Transit - Ningbo's current subway passenger flow intensity is 0.45 million passengers per day per kilometer, below the national standard of 0.7 million passengers per day per kilometer [2] - The majority of cities with operational rail transit lines are experiencing lower-than-expected passenger flow, with only a few cities exceeding the 0.7 million passengers per day per kilometer threshold [2] Group 3: Policy Implications and Future Directions - The national government has implemented regulations to standardize urban rail transit investments, requiring cities to meet specific economic and demographic criteria before project approval [3] - The reliance on real estate development for funding urban rail transit is becoming unsustainable, necessitating a shift towards more pragmatic planning and operations to ensure financial sustainability [3] - Future urban rail transit projects must prioritize fiscal affordability and realistic passenger flow estimates to achieve a balance between revenue and expenses [3]