Climate Change and Transit Infrastructure: The Benefits of Climate Vulnerability Assessments

Our climate is changing.  Now more than ever, we are paying increased attention to the significant risks of climate change on the performance of engineered transit systems and public safety.  Engineers, decision makers and other stakeholders are beginning to see the benefits of including climate change adaptation as part of their primary mandates. Vulnerability and risk assessments are becoming important steps to ensuring climate change is considered early in the engineering design, operations and maintenance of civil infrastructure.

Climate Vulnerability and Adaptation Planning  

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The Intergovernmental Panel on Climate Change (IPCC) defines vulnerability as the degree to which a system is susceptible to, and unable to cope with, adverse effects of climate change, including climate variability and extremes. Vulnerability is a function of the character, magnitude and rate of climate change and variation to which a system is exposed, its sensitivity to climate change, and its adaptive capacity.

Adaptation to climate change includes any activity that reduces the negative impact of climate change while taking advantage of new opportunities that may arise. Adaptation aims to minimize the expected or actual effects of climate change before or as they begin to occur. 

Understanding the components of transit infrastructure that are highly vulnerable to extreme weather conditions and climate change impacts allows for cost-effective planning and design, operations and maintenance.   

Climate Vulnerability and Risk Assessment

Climate vulnerability assessments can support adaptation planning in the following ways:

  • Identify areas most likely to be impacted by projected changes in climate.
  • Build an understanding of why these areas are vulnerable, including the interaction between climate change, non-climatic stressors and cumulative impacts.
  • Assess the effectiveness of previous mitigation strategies in the context of historic and current changes in climate.
  • Identify and target adaptation measures to systems with the greatest vulnerability.

The major steps in conducting a climate vulnerability and risk assessment include:

  • Set context and build team.
  • Assess current vulnerability.
  • Develop and apply future scenarios.
  • Estimate future vulnerability and risks.
  • Develop adaptation options.
  • Implement and mainstream adaptation.

The Need for Climate Vulnerability Assessments

Our existing transit systems have already experienced the impacts of climate change, and we can expect more. Most transit infrastructure and operations function well under varied weather conditions, but some have been known to be vulnerable to extreme weather events, such as increased temperatures, increased severity of precipitation, higher wind gusts and increased freezing rain. A transit system’s vulnerabilities may include:

  • Impacts to rail integrity due to extreme temperatures, intense rainfall and strong wind gusts.
  • Freeze-thaw cycles or heavy snowfalls causing ice and snow to accumulate between moving rails, blocking and freezing the switches that allow trains to move from one track to another.
  • Embankment instability caused by intense rainfall and overland flooding.
  • Stations and facilities affected by intense rainstorms, extreme heat and freeze-thaw cycles.
  • Power outages caused by intense rainfall, flooding and freezing rain.
  • Communication system vulnerability due to rainfall, flooding, extreme heat and freeze-thaw cycles.
  • Crews, staff and customer issues due to rainfall and flooding, freezing rain and ice storms, and extreme heat events.

These climate change impacts could increase the risk of delays, disruptions, damage and failure across a transit system, severely disrupting the reliability, capacity and safety of the system.

The information gained from conducting a climate vulnerability assessment can be used to determine possible needs and prioritize investments to increase resiliency, identify areas where it is reasonable to direct new growth, and identify areas that should be avoided.

Why Transit Organizations Should Enhance Their Adaptive Capacities.

In Canada, there are significant infrastructure investments on the horizon.  With those, there are significant opportunities to ensure capital projects include requirements for climate resiliency, making new and upgraded systems less vulnerable to disruptions resulting from extreme weather events.

Policies related to climate change, resiliency and adaptation have already been implemented at federal, provincial, regional, local and corporate levels, and continue to evolve. For example, Infrastructure Canada’s “Investing in Canada Infrastructure Program” (ICIP) includes a horizontal requirement called The Climate Lens. This requirement is intended to incite behavioral change and introduce the consideration of climate impacts into the planning of infrastructure projects, including transit, with a view to implementing Canada's goals of a clean growth low-carbon economy. The ICIP Climate Lens, in part, employs a risk management approach to anticipate, prevent, withstand, respond to, and recover from a climate change related disruption or impact. So, depending on the program, funding stream, and the estimated total eligible cost of the project, it is possible that proponents of transit projects will be required to undertake a “Climate Change Resilience Assessment”.

Metrolinx: Planning for Resiliency

A number of transit agencies, such as Metrolinx, have begun to include Climate Vulnerability Assessments into their mandates to strengthen their resiliency and adaptive capacity to climate related hazards. In 2017, Metrolinx produced a report titled Planning for Resiliency: Toward a Corporate Climate Adaptation Plan. The report, details their Vulnerability Assessment Pilot Project, which was an exercise meant to improve Metrolinx’s understanding of the vulnerability and risk of its assets to extreme weather events and climate change. The study resulted in:

  • More informed planning and decision making to help enhance the resiliency of the assets examined.
  • Highlighting needed improvements in monitoring and maintenance protocols.
  • Informing climate resiliency requirements for new capital projects.

Vulnerability assessments are now being considered for application across Metrolinx’s entire asset portfolio.  In fact, their Planning for Resiliency: Toward a Corporate Climate Adaptation Plan (2017) report suggests three reasons why all transit organizations should enhance their adaptive capacities in the face of a changing climate:

  1. Doing nothing would expose an organization to the full force of extreme weather events and impede their ability to meet organizational objectives.
  2. Canadians who depend on public transit have a growing expectation that organizations will consider climate change when planning, building and operating infrastructure.
  3. There is potential for adaptation measures to create new opportunities for job growth and prosperity i.e. through innovative engineering solutions.

In 2018, Metrolinx produced a follow up report titled Metrolinx Climate Adaptation Strategy. This report describes the organization’s commitment and approach to operate climate resilient transportation services. The strategy outlines 40 key actions being taken to keep trains, buses and LRTs running on time.

We know climate change can have impacts on our transit infrastructure. Conducting appropriate Climate Vulnerability and Risk Assessments during the early stages of a transit infrastructure project will better prepare an agency to adapt to climate change, reducing potential disruptions and public safety issues.

Ask our Experts

We conduct vulnerability and resiliency assessments to determine exactly where and what operations/ elements of your system are most vulnerable. The output of this exercise will provide data allowing you to perform an initial risk assessment for each operation or component of your transit system.

For more information on how we can help with your vulnerability and resiliency assessment requirements, please visit our Climate Resilience webpage or contact:

Jim TeepleJim Teeple, Principal, Practice Lead, Transit Operations & Maintenance
416-499-3110 x1011224


Andrew Harkness2 - small-1Andrew Harkness, Director, Environmental
613-739-2910 x1022258


Morrison Hershfield is a market leading, employee-owned professional engineering and management firm that has been making a difference since 1946. We deliver technically sophisticated, cost effective and sustainable infrastructure solutions across the globe.
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