Network diagnosis and governance-coupled optimization in seaport–dry port multimodal transport corridors under the Maritime Silk Road

Abstract

Research into seaport–dry port corridors has tended to focus on the design of the physical network on the one hand and the coordination of governance on the other. It is hard to maintain this separation in well-established Maritime Silk Road corridors. A corridor might have routes, inland nodes and digital platforms, and still not function smoothly at the rail/dry-port interface. This article therefore tackles corridor optimization as a problem of diagnosis and governance. It looks at the case of Ningbo-Zhoushan Port in a gateway province on China's eastern coast, and examines its relevance for Central Asian and landlocked economies relying on seaports, inland hubs, railways, customs facilities and digital platforms. The empirical basis comprises aggregated port planning and port transport-operation data from both the annual and quarterly perspectives as well as publicly available policy and industry material for contextual interpretation. The overarching question is pragmatic, and that is: If the side of the seaport is relatively on schedule, but the coordination on the inland rail side is not, where should optimization be targeted? The analysis links node-structure diagnosis, quarterly interface diagnosis and governance interpretation. To make the imbalance observable, the paper uses a Corridor Coupling Imbalance Gap (CIG), calculated as the difference between the mean completion rate of maritime-side indicators and the rail-freight completion rate at each quarter end. The evidence shows a stable three-part planned node structure for 2025–2026, but the 2025 rolling data also show that rail freight lagged maritime-side indicators for three consecutive quarters, with CIG reaching +10.20 percentage points in Q3. The main issue is thus not general seaport capacity. It lies in the translation from gateway capacity to inland consolidation, digital orchestration, and timely cross-actor intervention. The article proposes a governance-coupled optimization agenda organized around differentiated gateway roles, dry-port-centered consolidation, event-level digital coordination, and rolling warnings. Its contribution is to turn corridor optimization from a question of route expansion into a more precise diagnostic method for seaport–dry port governance.