Maritime traffic risk is increasing rapidly with the growth of marine traffic volume and construction of marine facilities, water bridges, port development, marine wind farm, etc. Given this emerging trend, this paper presents a bibliometric analysis and mapping of the broad academic literature related to maritime traffic safety, focusing on the influences of international collaborations and knowledge sources on the developments of this research domain. To identify trends, patterns and the knowledge distribution of the research on maritime traffic safety, the visualisation of similarities (VOS) viewer software, the bibliometric analysis, and scientometric mapping of the literature have been performed from the perspectives of publication and citation distribution over time, leading authors, countries (regions), institutions, the corresponding collaboration networks, most cited publications and references, focused research fields and topics, research trend evolution over time, etc. The paper provides a comprehensive and quantitative overview and significant picture representation of the domain's leading and evolutionary trends by employing specific aforementioned bibliometric analysis factors. In addition, by reviewing the evolutionary trends of the journals and the proposed investigated factors, such as the influential works, main research topics, and the research frontiers, this paper reveals the scientific literature's main research objectives and directions that could be addressed and explored in future studies.

A ship's perception of risk is an important basis for collision avoidance. To improve such perception, several risk measurement parameters on the ship domain are determined, including the approach factor, the time to domain violation (TDV) and the possible collision domain. Then, a risk hierarchy prewarning (RHP) model based on the violation detection of a ship domain is proposed, in which a two-level alarm scheme is adopted accordingly. A low-intensity alarm will be activated by reaching the minimum approach factor and the TDV threshold, and a high-intensity alarm will be activated by the factor of the possible collision domain and the TDV threshold. Subsequently, a novel guard zone in ARPA radar utilising the RHP model has been developed to establish a ship's risk perception system for officers on watch at sea. The model proposed in this paper can not only enhance the veracity of risk assessment around our own ship, but also be used as a decision support system for collision avoidance.