Megaregional adaptation and recovery priorities preserve local resilience in the US Northeast rail corridor

Rail transit systems are vital to urban mobility. This is especially true in emergent 'megaregions' consisting of regional hubs agglomerated into densely interconnected, polycentric conurbations. Infrastructure such as tracks and interchange stations are often shared between urban, regional, and intercity networks, enabling inter-system travel. However, their resilience to hazards is typically assessed on an individual system basis, seeking local optima that risk overlooking global concerns of robustness and adaptive capacity. We introduce a framework for comparative analysis of urban-to-megaregional rail transit resilience, combining measures of connectivity and ridership to capture tradeoffs between local and megaregional adaptation and recovery strategies. Results indicate that megaregional coordination can significantly benefit global resilience while preserving local priorities, with top strategies increasing global resilience by 12-41% and yielding global-local benefit-cost ratios of 2.5-4.3. Furthermore, we find that strictly local assessments poorly capture megaregional priorities, offering minor local benefits while missing opportunities to strengthen megaregion-wide resilience.