Abstract
<jats:p>The rise of intelligent and connected transportation has deepened power–transportation interdependence. Resilience assessment of these coupled systems under typhoons still faces two gaps: few studies incorporate dual functionality, and current metrics cannot capture vulnerability propagation. To bridge these gaps, we propose a metric framework built on a dual-dimensional composite performance function unifying power and transportation performance. This function underpins a five-stage valley-shaped resilience evolution model and seven geometric metrics covering the full restoration process. We also introduce a vulnerability-propagation polarity index to quantify propagation direction and strength, and a counterfactual method to quantify each coupling mechanism’s net contribution.</jats:p>