Extreme events from climate change will continue to cause disruption and damage to road networks. Despite the vulnerability of our infrastructure networks to natural disasters and climate events, they also play a critical role in boosting our resilience to these impacts.
Low-income countries and Small Island Developing States (SIDS) still need more reliable and resilient infrastructure systems. They are more vulnerable to disruptions, particularly from extreme events that increase in frequency and severity as the planet warms.
The Economist article warns that we will soon experience scorching temperatures as we breach the 1.5°C warming limit within the next five years. This means stronger hurricanes and storms, more ferocious wildfires, more extended droughts and heatwaves, and sea level rise, which can increase coastal flooding, and more intense snowstorms (How climate change, 2022).
The OECD report provides an exhaustive explanation of climate-resilient infrastructure, how to plan and design for it, and the importance of strengthening the enabling environment to support investment and build climate-resilient infrastructure.
Because we depend on our roads and transport networks for economic growth and social well-being, we need to ensure that these infrastructures are robust and resilient to the physical impacts of climate change.
According to the report, new infrastructure assets should be prioritized, planned, designed, built and operated to account for the climate changes that may occur over their lifetimes. Given the impacts of climate change, existing infrastructure may need to be retrofitted or managed differently. Decision-makers must have access to high-quality information, consistent data and the capacity to use this information to inform planning. Decision-makers can utilize tools like spatial planning frameworks and vulnerability maps, for example, to mainstream adaptation and encourage investments in resilient infrastructure.
A study published on 11 May 2023 in Environmental Research: Infrastructure and Sustainability aims to understand how road networks are affected by various disruptions, locate the hotspots of network vulnerabilities, and help prioritize and target future investments to increase road network resilience. Researchers analyzed the country-level network vulnerabilities using the available geospatial information of roads through OpenStreetMap (OSM).
Researchers looked at how a country’s road characteristic impacts the resilience of its road networks. These characteristics include economic such as income level or degree of urbanization, the terrain or geographic characteristics and whether the country is landlocked or not.
They have exposed 208 national road networks from various countries to different disruption schemes – random, local, and targeted disruptions, and see how these road systems respond to various natural hazards. The study classifies a flash flood as a local or targeted attack and a winter storm as a random attack.
Researchers took the following steps to assess country-level road networks’ vulnerability to various disruptions:
- They prepare each country’s network for analysis, standardizing them for comparability.
- They designed an origin-destination (O-D) matrix reflecting the travel flows within each country and assigning 100 unique O-D points to each country.
- They run random, local, and targeted attacks on each country’s network.
- They analyze the outcomes by identifying which country and network characteristics explain the level of disruption caused by each attack, what part of the country’s network causes the largest disruptions and its associated societal costs.
Researchers have also developed a national road vulnerability index (NRVI) which allowed them to rank countries according to the vulnerability of their national road networks by combining the results of each country’s targeted, local, and random attacks.
Their results show that the United States, China, and India have some of the lowest network vulnerabilities. In contrast, Comoros, Bhutan and Trinidad and Tobago have the highest overall road network vulnerability.
Countries with the largest road networks are generally the least vulnerable to disruptions. However, some of the smallest networks are the most vulnerable.
Among the most vulnerable countries are SIDS, such as Nauru and Saint Lucia, highly mountainous countries like Bhutan and Andorra, and some of the lowest-income countries, such as Somalia and Madagascar.
The results highlight that from an equity perspective, transport infrastructure investments, such as the building of new roads, are more desired in low-income country networks in Central America, the Caribbean, Sub-Saharan, Africa, Southeast Asia, and the Pacific, and should be prioritized, provided that the geography of these countries will allow for more redundancy in the networks.
In other countries, strengthening critical road segments, especially those exposed to natural hazards and threats, should be prioritized.
The coming years will be the hottest ever. (2023, May 17). The Economist. Retrieved from https://www.economist.com/science-and-technology/2023/05/17/the-coming-years-will-be-the-hottest-ever
How Climate Change is Fueling Extreme Weather. (2022, September 28). Earth Justice. Retrieved from https://earthjustice.org/feature/how-climate-change-is-fueling-extreme-weather
Koks, E., Rozenberg, J., Tariverdi, M., Dickens, B., Fox, C., Ginkel, K., & Hallegatte, S. (2023 May 11). A global assessment of national road network vulnerability. Environmental Research: Infrastructure and Sustainability. Retrieved from https://iopscience.iop.org/article/10.1088/2634-4505/acd1aa