Multi-period human evacuation model for passenger ships under walking speed uncertainty

An effective evacuation model can steer passengers from unsafe zones to safety in a time-sensitive manner on passenger ships. The International Maritime Organization highly recommends constructing robust evacuation models rooted in understanding human behavior and ship design. This study addresses the challenge by focusing on walking speed, a key determinant of human behavior, the capacity of transitional points (e.g., exit stairs), and the distance of passengers to the exit stairs for a safe and rapid evacuation. This study presents a multi-period human evacuation model aimed at optimizing the evacuation time of the slowest passenger, identifying the optimal number of stairs, and planning route evacuation under passenger walking speed uncertainty affected by the heeling angle for a deck of a passenger ship. A robust optimization approach is also employed to manage uncertainty by defining uncertainty sets for passengers' walking speeds. The computation of the price of robustness spans various test problems at various levels of conservatism. This research offers multiple managerial implications for maritime industry leaders, paving the way for more efficient evacuation planning.