The growing frequency of extreme events, such as winter storms, hurricanes, and extreme temperatures, disrupts the regular operation of the air transportation systems, causing travel delays and subsequent economic costs to travelers, airports, and airline careers (Doll, Klug et al., 2014). Despite the increasing awareness of the impacts of extreme weather events on air transportation, the extent of impacts on passenger travel delays is not fully understood nor quantified. It is estimated that the hazards of extreme weather events will be further aggravated due to the greater likelihood and severity of events (IPCC, 2018) and consequential impacts on air transportation. Thus, it is critical to better understand and quantify the impacts of extreme weather events on air transportation systems, especially from the perspective of passenger delays.
Previous studies have pinpointed the primary climate events affecting the airports’ infrastructure and operations, including sea-level rise and urban flooding, extreme temperatures, intense storms, and heavy precipitation. (ICAO, 2021). These extreme weather events can take place individually and jointly and give rise to complicated, intertwined, and ripple effects on the operation and security of airport systems. For example, the accompanying strong winds of intense storms could threaten the aircraft safety during takeoff and landing, and may also require runway closure in extreme cases, causing substantial flight delays and cancellations. Strong storms usually bring about heavy precipitation within a short period of time, which in turn could overwhelm airports’ drainage systems (Voskaki, Budd et al., 2023). In 2013, a severe winter storm combined with heavy precipitation at London’s Gatwick Airport caused delays and disruption for more than 16,000 travelers during the Christmas holiday season (Agency, 2016). Abnormal temperatures (extreme heatwaves and cold snaps) are another significant threat to airport infrastructures brought by climate change. Very high and low temperatures can cause equipment failure and improper operations. Also, extreme temperatures can affect runway performance. Very high temperatures can cause the runway to be excessively soft, making an unstable base for aircraft landing (De Vivo, Ellena et al., 2021). For example, in July 2018, prolonged high temperatures caused serious damage to the north runway of Hanover Airport in Germany and resulted in dozens of flight cancellations. Very low temperature may increase the runway’s slipperiness and undermine the planes’ braking effectiveness (Nuijten, 2016). Another effect of extreme temperatures is the planes’ maximum takeoff weights, which are affected by the changing air density due to humidity and temperature fluctuations and are especially influential for airports with higher altitudes and shorter runways (Zhao, 2020).
The increased frequency and intensity of extreme weather events highlights the importance of understanding the impacts of these events on air transportation systems and subsequent economic and social consequences. Most existing studies (such as Chen and Wang, 2019; Zhou and Chen, 2020) focused primarily on examining the impacts of extreme weather events on air transportation systems based on analyzing the extent of flight cancellations and flight delays. Such impacts on the flight delays are typically characterized as the time difference between the scheduled and actual flight departure/arrival (Borsky and Unterberger, 2019). Flight cancellations and flight delays, however, do not fully capture the extent of effects on passenger travel delays. This limitation can be effectively addressed using location-based data.
The emergence of location-based services has given rise to novel risk evaluation approaches based on fine-grained human mobility datasets (Liu et al., 2021; Coleman et al., 2022; Zhang and Li, 2022). Such datasets can provide high spatiotemporal resolution insights regarding population activity and mobility that can be used to understand how people move, act, and respond in hazard scenarios (Wang et al., 2020; Lee et al., 2022; Liu et al., 2022; Rajput et al., 2022; Rajput et al., 2022). By evaluating the changes in population activity and mobility patterns, the extent of impacts of hazard-induced disruptions can be effectively evaluated (Hsu et al., 2022; Lee, et al., 2022; Rajput and Mostafavi, 2022; Wang and Taylor, 2016; Liu et al., 2019). While location-based data has been used for evaluating hazard-induced perturbations in different infrastructures (Lee et al., 2022), the use of these high-resolution data has been rather limited in examining the vulnerability of air transportation systems to extreme weather events. This study addresses this gap and uses fine-grained location-based data for examining the effects of a recent extreme weather event, 2022 Winter Storm Elliott, on the U.S. air transportation system by quantifying and comparing the passenger delay (derived from passenger dwell time at airports).
Our dataset captured 41,344,261 anonymized trips at 62 major U.S. airports and records their dwell time during the steady-state period (December 21–26, 2021) and perturbation period (December 21–26, 2022). By comparing changes in passenger dwell times across different regions and time periods, this study aims to answer the following specific questions: (1) the extent to which the extreme weather events disrupt the air transportation system and which are the most disrupted airports from a passenger-delay perspective; (2) the extent to which airports are affected by direct hazard exposure versus cascading impacts through network effects; (3) the extent to which the airlines’ operating models (decentralized versus centralized) affects the vulnerability of airports. Figure 1 shows the framework for this study, including the data used, metrics computed, and the types of analysis performed to address our research questions. The details related to the dataset and methods are discussed in the next section.