Improving the safety of the working environment in Indonesia’s construction industry presents significant challenges. Researchers have sought to identify key factors influencing safety performance. As an archipelago, Indonesia requires extensive port construction, therefore the identification of these factors is crucial for enhancing construction safety. This study aims to determine these factors and dominant risks associated with work safety and to explore their relationships. The research utilizes Interpretive Structural Modeling (ISM) to reveal the overall structure among these factors, followed by Fuzzy MICMAC (Matrix of Cross Impact Multiplications Applied to Classification) analysis. The results showed that “extreme weather” and “force majeure” are the most significant factors impacting safety in both sea and land construction works. Additionally, the study revealed the interdependencies among safety risk variables in these construction environments. These findings provide valuable insights for the effective development of measures to implement safety programs in the construction sector.