Exploring the synergy between regional cooperation and transport connectivity for sustainable regional development: an empirical study of the pearl river delta (PRD) mega- city cluster, China

Transport networks are pivotal not only as conduits for resource distribution but also as mechanisms driving regional connectivity. These systems facilitate the flow of freight, services, and labour, fostering spatial connectivity. However, the relationship between regional cooperation and transport connectivity development remains contentious especially in urban clusters. This study investigates the multi-effect role of regional cooperation on transport infrastructure in the Pearl River Delta (PRD) from 2013 to 2022. Leveraging SnowNLP-based text mining, the research analyzes cooperation in social, economic, environmental, institutional, and transport affairs. A regional transport connectivity index (RTCI) framework, incorporating key dimensions such as infrastructure quality, investment capital, and operational performance, is constructed, with weights assigned via the Bayesian Best-Worst Model. The results underscore the following: (1) Core cities like Guangzhou and Shenzhen have driven transport connectivity improvements, while peripheral cities have lagged, exposing critical regional disparities despite the regional integration policy. (2) Social cooperation was closely related to transport network expansion, while economic cooperation exhibits a siphoning effect, disproportionately benefiting core cities and straining peripheral regions. (3) Though less impactful on RTCI, institutional cooperation still provides an important foundation for governance frameworks. (4) Transport cooperation directly contributes to the growth of transport networks by facilitating coordinated infrastructure planning and development. These insights highlight the importance of integrating cohesive transport strategies with regional policies deepening multi-dimensional cooperation for rapidly developing urban regions like PRD. The study concludes by advocating for coordinated regional strategies that enhance connectivity and support sustainable growth without exacerbating existing disparities.