The Impact of Regulation Amendments on Decision Support System Effectiveness on the Example of Vessel Traffic Planning on the Dredged Świnoujście–Szczecin Fairway

Detailed planning of vessel traffic on the fairway, carried out by Vessel Traffic Service (VTS) operators, is a complicated task, especially when there are restrictions for two-way ship traffic. Such restrictions take place on the dredged Świnoujście–Szczecin fairway in Poland. After the dredging of the fairway to 12.5 m, vessel traffic regulations introduced in a Port Regulations document have changed, which impacted the course of the decision-making process related to planning vessel traffic on the fairway performed by VTS operators. The aim of the article is to assess the probability of making erroneous decisions related to the admission of non-compliant vessels to traffic on the dredged Świnoujście–Szczecin fairway after the introduction of new vessel traffic regulations. In the article, the tasks carried out by VTS operators during vessel traffic planning were described and analyzed using Failure Mode and Effects Analysis (FMEA) method. The probability of making an erroneous decision at each stage of the planning process was calculated using the Human Error Assessment and Reduction Technique (HEART) method. An event tree was developed in relation to VTS operators’ decision-making on vessel traffic planning performed before and after the introduction of a decision support system (DSS). An expert method was used to determine the probability values. Recommendations were proposed to reduce the risk of making erroneous decisions by VTS operators while vessel traffic planning. The research results contributed to the expansion of knowledge on the impact of new regulation implementation on vessel traffic safety and the risk of making erroneous decisions related to the admission of non-compliant vessels to traffic on the dredged Świnoujście–Szczecin fairway, considering the implementation of a DSS. The results of the study may be of interest to VTS operators, port authorities and maritime administrations.