Assessing the relocation of port customs facilities beyond port boundaries as a congestion mitigation strategy: evidence from three port systems

Customs clearance procedures remain a critical yet underexamined source of congestion in maritime ports. While the literature on port regionalization and dry ports has addressed the spatial redistribution of cargo handling functions, limited attention has been paid to the spatial configuration of customs facilities as a strategic design variable. This paper evaluates the operational and logistics impacts of relocating customs inspection facilities outside port boundaries through a hierarchical optimization–simulation framework. The methodology is applied to three port systems: Genoa (Italy), Altamira (Mexico), and Montevideo (Uruguay), to derive managerial and policy insights. Results indicate that partial relocation of inspection flows reduces customs queue intensity and internal truck interference, although the magnitude of benefits is strongly context-dependent. The elasticity of queue length and truck utilization with respect to inland allocation exceeds that of total system cost, suggesting that customs relocation primarily releases effective capacity rather than generating substantial cost savings. Hybrid configurations outperform pure strategies across heterogeneous institutional and infrastructural environments. These findings extend port regionalization theory by demonstrating that administrative functions can drive spatial reconfiguration and congestion mitigation within port–hinterland systems. Customs relocation thus emerges as a scalable strategy to enhance operational resilience and throughput without requiring immediate physical expansion.