Sinking Airports: A Glance at the State of US Transport Infrastructure

Land subsidence poses a growing challenge to the operational safety and structural integrity of global air transport infrastructure. This study assesses the impact of differential land subsidence on airport runways using cutting-edge Interferometric Synthetic Aperture Radar (InSAR) data across 15 major U.S. airports, providing an estimate of potential foundational damage caused by settlement due to natural and anthropogenic factors. Our findings show San Francisco International Airport experiences the fastest subsidence rate of 9.2 ± 0.2 mm/year, while Los Angeles International Airport has the slowest subsidence rate of 2.0 ± 0.2 mm/year. While 96.1% of runway areas fall under low damage risk, 3.9% are at medium to very-high (VH) risk, with 3.5 million m² exposed to subsidence rates exceeding 5 mm/year and 13,950 m² classified as being at high to VH damage risk. Although no accidents have been directly linked to subsidence, increasing maintenance costs underscore the need for proactive monitoring. InSAR provides a near real-time, cost-effective solution for detecting infrastructure vulnerabilities, offering a non-intrusive approach to enhancing airport resilience and operational safety.