In the event of road or bridge closures due to extreme events damages like earthquakes, floods, wildfires, and others, can the transport network still allow access to essential services and amenities to residents affected?
When calamity hits a specific area, access to food, hospital or emergency services, schools, and even recreational activities supports residents’ fast recovery and increases resilience.
A community’s resilience is linked to its transportation network and whether it is truly serving the community’s needs by providing adequate and equitable access to amenities and services amid disruptions and disasters.
A paper by M.J. Anderson, D.A.F. Kiddle, and T.M. Logan, “The underestimated role of the transportation network: Improving disaster & community resilience,” published in Transportation Research, investigated the role of the transportation network in providing adequate and equitable access to amenities and services, which is key to community resilience.
Disruption to transportation networks caused by extreme weather events can indirectly affect the community.
The authors gave the following examples of the indirect effects of disruptions to infrastructure due to calamities and natural disasters.
The 2018 earthquake and tsunami in Indonesia has damaged many of its buildings and road infrastructures, preventing kids from going to school, lasting up to two years after the event.
When Katrina hit in 2005, its direct impacts could be seen in the closure of many roads and services.
But even after the roads had opened, supermarkets remained closed for many years, causing residents to take three buses to buy groceries.
Mitchell Anderson, the study’s lead author, writes:
“While numerous studies have been completed to understand the reliability and resilience of transport networks, current assessments often neglect two things: the wider objective of the network (which is to allow people to travel between destinations of interest) and the variety of needs (and therefore destinations) of the people that the network serves.”
“Yet, the transport network is all-but redundant if there are no operable destinations. Without considering the operational status of destinations, fixation on the network’s functionality can lead to a distorted understanding of the impacts that disruption has on access and community function.”
“Therefore, to better understand the resilience of a transportation network and its impacts on a community, we must reconsider and broaden the approach to measure that resilience.”
“To address these gaps, our objective was to enhance the understanding of the role of the transportation network in community resilience.”
“We achieve this by developing and demonstrating an approach to evaluate the direct and indirect impacts of a disruption on a transportation network and the community’s ability to access services.”
“The approach is based on the ability to modify the transport network for an entire city to reflect potential damage (direct impacts), in a manner that is computationally efficient and therefore practicable to integrate into repeated hazard simulation.”
“To measure the indirect impacts, we evaluate how a community’s access, and the equity of that access, changes as a result of the transportation network’s disruption and closures to essential services. This enables a better and broader understanding of how and where residents will be affected by potential hazards.”
“To demonstrate this approach with different types of hazards (earthquake liquefaction, pluvial flooding, and tsunami), we consider three cities: Seattle (WA, USA), Houston (TX, USA), and Christchurch (New Zealand).”
“These case studies are used to demonstrate (1) how access and access equity changes across different demographic groups, incorporating uncertainty; (2) regions prone to isolation and their demographics composition; and (3) the potential for multi-criteria optimisation to aid decision-makers in the process of coordinating an equitable restoration program.”
As the study demonstrates, transport networks support community resilience.
Knowing the direct and indirect impact of transportation disruptions on communities will help urban planners and emergency managers provide better and equitable access to support community resilience and speed up recovery.
Read the entire study by clicking on the link provided in the citation below.
M.J. Anderson, D.A.F. Kiddle, T.M. Logan, The underestimated role of the transportation network: Improving disaster & community resilience, Transportation Research Part D: Transport and Environment, Volume 106, 2022, 103218, ISSN 1361-9209, https://doi.org/10.1016/j.trd.2022.103218.
This blog post first appeared on the Climate Adaptation Platform. We shared it here because of its relevance to the transportation network’s resilience.