Defining Transportation Systems Resilience under Natural Disasters: A Bibliometric Analysis Based on Mode, Metrics and Scope

Climate change is causing changes in the distribution of natural disasters in countries. Major disaster relief plans rely on the availability of transportation systems during disasters; however, transportation systems (road, rail, air, etc.) are also vulnerable to disruptions of natural disasters such as hurricanes, floods, etc. While each disaster may cause a different type of disruption to a transportation network (flooding, road closures, facility failures, etc.), each transportation system also has a different resilience to a disaster. For example, air services may not be available during a hurricane but may be available during an earthquake. Thus, it is necessary to define “transportation systems resilience”, which is the aim of this study. To derive the necessary resilience parameters for different transportation systems, a bibliometric analysis was performed using Bibliometrix on literature search results of 3350 abstracts from the Web of Science (WoS) database using the keywords “resilience” and “transport”. Reviewed articles were classified based on a) transportation systems, b) disaster types, and c) resilience index types. Descriptive and visual evaluation of the bibliometric analysis showed that there has been a growing interest in the topic since 2010, with an exponential increase. A further selection of 279 studies using title-based search allowed a more detailed analysis; the results showed that resilience measurement parameters can vary significantly between transportation systems. The resilience index definition is not straightforward for transportation systems; it is necessary to clarify the resilience scope, including the vulnerability of critical transportation infrastructures (bridges, airports, etc.), as well as accessibility to and within a disaster region. Transportation system resilience must be defined in a multi-scale (city, intercity, national, etc.) and multi-hazard (floods, hurricanes, etc.) scope for a region, where the vulnerability of different transportation systems needs to be evaluated separately to estimate the total resilience in the region.