Examining the relationship among supply, service, and attractiveness of urban public transport under the “dual carbon” objective

Under the “Dual Carbon” goal, China has implemented the Transit Metropolis policy to foster sustainable urban transport. This study explores the coupling and coordination among public transport supply, service, and attractiveness in pilot cities, using an evaluation index system adapted to four city types. The coupling degree is used to analyze the extent of interaction among the three subsystems of urban public transport, while the coupling coordination degree further evaluates the level of coordinated development among these subsystems based on the coupling degree. This study proposes a novel methodological framework that integrates the entropy weight method with the coupling coordination degree (CCD) model to evaluate the coordination level among the three subsystems. This approach offers actionable insights for enhancing urban public transportation systems. 

The findings show that the comprehensive evaluation of the three public transport subsystems improved from the initial to the acceptance stage of the Transit Metropolis policy. The coupling degree reached a high level, and the coupling coordination degree (CCD) also advanced. Megacities achieved extreme coupling coordination, while the other three city types reached a high level, approaching the extreme coordination. 

Based on these findings, policy recommendations are proposed to address disparities in the coupling and coordination among the four city types. These recommendations aim to guide relevant government departments in encouraging the sustainable development of urban transportation, contributing to balanced and sustainable growth across diverse urban environments.