How Many Alternatives Should an Emergency Directory Show? A Synthetic Monte Carlo Study of Stale Status, Capacity Constraints, and Route Disruption

This manuscript presents a synthetic Monte Carlo simulation examining how the number of alternatives displayed by a digital emergency shelter directory interacts with stale shelter-status information, capacity constraints, and route disruption. The study compares shortlist policies under simulated scenarios and explores how results depend on assumptions about fallback-search delays. All scenarios and results are generated computationally. The study does not use real evacuation records, does not represent measured conditions in Bahrain, and has not been validated against real-world emergency outcomes. The accompanying files provide simulation code and summary results to support reproducibility. Keywords: emergency shelter allocation; evacuation; Monte Carlo simulation; decision support; route disruption; uncertainty modelling. This manuscript is a research preprint and has not been peer reviewed.