Research on safety and efficiency warranted vessel scheduling in unidirectional multi-junction waterways of port waters

•Propose a framework to calculate the safe distance of ships in port while sailing in detail.•Propose a key collision avoidance point precomputation model to calculate the appropriate action time for vessels in advance.•An integrated vessel scheduling approach (IVSA) is proposed and developed to obtain the safety-enabled optimal vessel scheduling.•The new scheduling approach proposed in this paper is superior to the traditional strategies. Traffic management in port waters is a complicated task considering vessels with various characteristics and the specific layout of waterways. Optimal management is needed to reduce vessel waiting time and guarantee adequate safety, which in turn could enhance port competitiveness, and is conducive to port development. In this paper, a key collision avoidance point precomputation model is proposed to assess the safety level of each vessel scheduling plan and the consequent efficiency in unidirectional multi-junction waterways of port waters. An integrated vessel scheduling approach (IVSA) is proposed and developed to obtain the safety-enabled optimal vessel scheduling with the purpose to minimize the total delay under the premise of adequate safety. A series of experiments has been conducted by employing data of an empirical port in northern China. It is found that, in addition to improving traffic environment and reducing unnecessary behavior of vessels, IVSA could substantially reduce the total delay, from 6.04% to 27.75%. Result of this research can provide a guidance for port seaside management under complex situations and provide the decision-making support for the assessment of vessel traffic on future port waterway expansion.