Integrated AIS Collision-Risk Mapping in the Lombok Strait TSS

Abstract

This article develops an auditable Automatic Identification System (AIS) framework for collision risk mapping within the Lombok Strait Traffic Separation Scheme. The framework combines track reconstruction, pairwise encounter detection, distance and time to closest approach point, speed-adjusted two-way vessel domain, exposure-adjusted temporal and vessel class comparison, and Kernel Density Estimation. Because the original raw AIS records are available for analysis, this ready-to-use prototype uses a clearly identified synthetic dataset and should not be submitted as an empirical article. The dataset contains 1,286,430 AIS messages, 5,982 valid track segments, and 2,135 encounter events. Crossing situations constitute 42.0% of the encounters; 18.0% are classified as high CPA urgency and 19.3% involve vessel domain violations. Hypothetical high-risk levels were higher at night than during the day (23.8% versus 13.0%; odds ratio 2.09), while the associated violation rates were 24.3% and 15.0%. Events involving ferries showed the highest exposure-adjusted violation rates, and the northern prevention zone had the greatest synthetic spatial risk intensity. This framework resolves previous denominator and intersection inconsistencies by separating encounter frequency, kinematic urgency, geometric intrusion, exposure, and spatial concentration. All outcome values ​​derived from the original AIS and VTS records are subject to scientific interpretation