## 6 Discussion  
The results demonstrate that redesigning rectangular precautionary areas into circular roundabouts improves the traffic flow and safety, which aligns with findings from similar studies in road transport. The calculated entry capacities and volume-to-capacity ratios confirm that the adoption of roundabout principles enhances vessel maneuverability and reduces navigational conflicts. These findings suggest that maritime environments can benefit from concepts traditionally applied to road transport, thereby contributing to safer and more efficient operations in high-traffic waterways. The Lombok Strait serves as an ideal case study due to its strategic and ecologically significant location within the Coral Triangle--often referred to as the \"Amazon of the Seas\"--and in proximity of the Nusa Penida and Gili PSSA, home to 296 coral reef species [52]. This strait is a critical maritime gateway between the Indian and Pacific Oceans via the Makassar Strait and ASL II routes, thus requiring extensive marine traffic management. While protective measures such as the establishment of a TSS and VTS have been implemented, the increasing volume of traffic necessitates further measures, limiting the scope of this study to this specific area. The analysis of the AIS data in Table 3 reveals that only 33% of ships adhered to the designated precautionary area despite warnings and penalties from the VTS. According to the VTS, these violations often occurred as ships followed the natural course of their voyage toward their destinations, dishonoring the organized path enforced by the VTS as depicted in Figure 7, and emphasized the need for additional measures to improve vessel movements. Special attention must be paid to high-speed craft traffic using routes C1 and C2, which only crossed the given precautionary area during specific times, such as at approximately 8 a.m. Similarly, ferries that frequently crossed using routes D1 and D2 also need to be warned, underscoring the need for stricter monitoring and enforcement in these routes. This was also highlighted in previous research [53]. To address these challenges, the result of this study could serve as a proactive approach for the Indonesian Maritime Administration, urging all concerned domestic shipowners operating in the area to take necessary actions. Additionally, Indonesian maritime education and training institutions should emphasize the finding of this study regarding domestic ship behavior into relevant curricula to promote safety and ensure compliance with the TSS regulations. In contrast, the design on the roundabout demonstrates several advantages: Roundabouts provide a self-regulating system that inherently reduces conflict points (from 168 to 36 in this study) and improves safety through structured and predictable vessel movements. This comparative analysis underscores the roundabouts potential to complement and enhance existing strategies. The overall roundabout capacity and performances in Table 6 indicate that the roundabout is able to operate efficiently across all existing routes, with values below the threshold, signifying satisfactory performance. Hazard maps in Figure 15 indicate an overall improvement in the safety of navigation through the proposed roundabouts and confirm the existence of conflict points, as shown in Figure 13b. To address these risks effectively, the VTS must implement additional control measures to reduce the conflict points. This may involve regulating the crossing angle and entry direction while considering the speed and maneuverability of the ships and domain, as shown in Figure 11. Additionally, the VTS should encourage all ships to adhere strictly to collision regulations, ensuring that vessels will naturally evade one another within the designated roundabouts. This finding also aligns with previous studies [28, 30], which highlighted the importance of control measures for managing roundabouts in marine traffic.