The Vertical Evacuation Problem: Why High-Density Cities Are Systematically Unprepared for Cascading Infrastructure Failures
Objective
Assess the evacuation and resilience capacity of cities with >50% high-rise residential density during simultaneous infrastructure failures (power, water, elevators, communications) triggered by climate events or cyberattacks.
Methodology
Simulation modeling of cascading infrastructure failure scenarios in 8 high-density cities (Singapore, Hong Kong, Dubai, NYC, Shanghai, Mumbai, Toronto, Melbourne). Agent-based evacuation modeling using census-level population distribution. Cross-referenced with actual emergency response data from COVID lockdowns and past disaster events.
Findings
Cities with >40% population in buildings above 15 floors have evacuation completion times 6-8x longer than low-rise equivalent. Simultaneous elevator failure + power outage creates mobility-trapped population of 12-31% in modeled cities. Medical emergency response times increase 340% in high-rise dense zones during infrastructure cascade. Only 2 of 8 cities studied had evacuation protocols accounting for >10-floor vertical mobility impairment.
Key Assumptions
- •Simulation parameters calibrated against historical disaster response data are transferable to novel cascades.
- •Building access and population distribution data is current within 2 years.
Limitations
- •Agent-based models cannot fully capture behavioral responses to novel disaster types.
- •Political willingness to implement vertical evacuation infrastructure varies widely.