Developing a Multi-Objective Maritime Vehicle Routing Framework for Integrated Passenger–Cargo Services in Small Island Networks: A Scenario-Based Assessment of the Thousand Islands, Indonesia

Abstract

Maritime transportation plays a critical role in maintaining mobility, logistics distribution, and regional connectivity in archipelagic regions. However, small-island transportation systems frequently experience operational inefficiencies arising from fragmented passenger and cargo services, low vessel utilization, accessibility disparities, and empty sailing movements. These challenges are evident in the Thousand Islands Regency (Kepulauan Seribu), Indonesia, where government-subsidized passenger vessels operate alongside traditional passenger–cargo services, resulting in duplicated operations and uneven service accessibility. This study develops a Multi-Objective Maritime Vehicle Routing Framework (MO-MVRF) to support integrated passenger–cargo transportation planning in small island networks. Unlike conventional maritime vehicle routing approaches that primarily focus on cost minimization, the proposed framework simultaneously incorporates operational efficiency, accessibility equity, vessel utilization, and passenger–cargo service integration within a unified decision-support structure. Using operational data from January–December 2024, including vessel movements, passenger demand, cargo service records, and inter-island distance matrices, the study evaluates existing network performance through three indicators: the Empty Sailing Index (ESI), Island Accessibility Deficit Index (IADI), and Cargo Accessibility Index (CAI). The analysis identified 328 empty departure trips and 530 empty arrival trips, representing 8.88% and 13.86% of annual vessel movements, respectively. Significant accessibility disparities were also observed, with Harapan and Sabira Islands experiencing service absence during 64.7% and 56.2% of operational days, respectively, while cargo services remained concentrated on a limited number of islands. A scenario-based evaluation was subsequently conducted to compare the existing fragmented transportation arrangement with the proposed integrated routing concept. The results indicate that the proposed framework can support demand consolidation, reduce empty sailing occurrences, improve vessel utilization, and enhance accessibility for peripheral islands through feeder-based service integration. The study contributes to the maritime transportation literature by extending multi-objective vehicle routing concepts to integrated passenger–cargo services in small island environments and provides a transferable framework for policymakers and transport operators seeking more efficient, equitable, and sustainable maritime transportation systems in archipelagic regions.