## 2 Literature Review
### Introduction to Hinterland Connectivity  
In this section, we explore the critical concept of hinterland connectivity, focusing on how efficiently ports connect with their surrounding regions to facilitate cargo movement. Hinterland connectivity encompasses the transportation infrastructure and logistical systems that link ports to inland destinations, including roads, railways, and other transport modes [14; 15]. Effective connectivity is essential for optimizing cargo flow, reducing transit times, and ensuring timely delivery of goods [16; 17].  
The study on hinterland transport connectivity [18] underscores its pivotal role in port competitiveness, placing it just behind port costs. The review traces the evolution of port-hinterland relationships from early 20 th-century models to the transformative effects of containerization in the late 1960s. It highlights a shift from distance-decay to functional approaches in analyzing these relationships, emphasizing the growing importance of hinterland network dynamics over individual port performance. As business trends and technological advancements accelerate, the study advocates for leveraging enhanced regional network intelligence to better understand and adapt to these changes.  
The study [19] examines the impact of international land-sea transport corridors on port competition between neighboring countries using the Hoteling model. It highlights that while these corridors improve transport efficiency, trade integration, and inland access to markets, they also intensify competition among ports. The findings show that high cross-border transportation costs reduce the market share of overseas ports, while high maritime transportation costs offset the land transport advantages of these corridors, favoring domestic ports. This research emphasizes the need for balanced cross-border and maritime transport costs to maximize the benefits of transport corridors and supports strategic decision-making in port development and policy planning.  
Another study [14] highlights the critical role of hinterland connectivity in port competitiveness, emphasizing its evolution from local to multimodal perspectives. Traditionally, hinterland connectivity was assessed based on direct service connections, but with increasing intramodality, this local view is inadequate. By applying complex network science, the study expands the definition of connectivity to include non-local and multimodal elements. It finds that multimodal routes and transfer connections greatly enhance overall connectivity, showing that ports with limited local connections can still be well-positioned within a broader network. Multimodal integration benefits all ports, though some, particularly multimodal hubs, gain more than others.  
Also, the study [20] investigates how seaports and their hinterlands shape national spatial structures, focusing on Iran over the past two decades. Using social network analysis, the research examines the intensity, direction, and concentration of commodity flows between ports and hinterlands. The findings reveal that southern Iranian ports have bolstered the centrality of key inland cities, particularly Tehran, Bandar Abbas, and Mahshahr Port. Tehran, as the primary hub, plays a pivotal role in commodity production, consumption, processing, and distribution, influencing regional and local logistics. This pattern, characterized by strong core-port connectivity, represents a distinct phase in the evolution of port-hinterland relationships.